web 기본셋팅

backend/node_modules/mysql2/License

@@ -0,0 +1,19 @@
+Copyright (c) 2016 Andrey Sidorov (sidorares@yandex.ru) and contributors
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE.

backend/node_modules/mysql2/README.md

@@ -0,0 +1,114 @@
+[npm-image]: https://img.shields.io/npm/v/mysql2.svg
+[npm-url]: https://npmjs.com/package/mysql2
+[node-version-image]: https://img.shields.io/node/v/mysql2.svg
+[node-version-url]: https://nodejs.org/en/download
+[downloads-image]: https://img.shields.io/npm/dm/mysql2.svg
+[downloads-url]: https://npmjs.com/package/mysql2
+[license-url]: https://github.com/sidorares/node-mysql2/blob/master/License
+[license-image]: https://img.shields.io/npm/l/mysql2.svg?maxAge=2592000
+[node-mysql]: https://github.com/mysqljs/mysql
+[mysqljs]: https://github.com/mysqljs
+[mysql-native]: https://github.com/sidorares/nodejs-mysql-native
+[sidorares]: https://github.com/sidorares
+[TooTallNate]: https://gist.github.com/TooTallNate
+[starttls.js]: https://gist.github.com/TooTallNate/848444
+[node-mariasql]: https://github.com/mscdex/node-mariasql
+[contributors]: https://github.com/sidorares/node-mysql2/graphs/contributors
+[contributing]: https://github.com/sidorares/node-mysql2/blob/master/Contributing.md
+[docs-base]: https://sidorares.github.io/node-mysql2/docs
+[docs-base-zh-CN]: https://sidorares.github.io/node-mysql2/zh-CN/docs
+[docs-base-pt-BR]: https://sidorares.github.io/node-mysql2/pt-BR/docs
+[docs-prepared-statements]: https://sidorares.github.io/node-mysql2/docs/documentation/prepared-statements
+[docs-mysql-server]: https://sidorares.github.io/node-mysql2/docs/documentation/mysql-server
+[docs-promise-wrapper]: https://sidorares.github.io/node-mysql2/docs/documentation/promise-wrapper
+[docs-authentication-switch]: https://sidorares.github.io/node-mysql2/docs/documentation/authentication-switch
+[docs-streams]: https://sidorares.github.io/node-mysql2/docs/documentation/extras
+[docs-typescript-docs]: https://sidorares.github.io/node-mysql2/docs/documentation/typescript-examples
+[docs-qs-pooling]: https://sidorares.github.io/node-mysql2/docs#using-connection-pools
+[docs-qs-first-query]: https://sidorares.github.io/node-mysql2/docs#first-query
+[docs-qs-using-prepared-statements]: https://sidorares.github.io/node-mysql2/docs#using-prepared-statements
+[docs-examples]: https://sidorares.github.io/node-mysql2/docs/examples
+[docs-faq]: https://sidorares.github.io/node-mysql2/docs/faq
+[docs-documentation]: https://sidorares.github.io/node-mysql2/docs/documentation
+[docs-contributing]: https://sidorares.github.io/node-mysql2/docs/contributing/website
+[coverage]: https://img.shields.io/codecov/c/github/sidorares/node-mysql2
+[coverage-url]: https://app.codecov.io/github/sidorares/node-mysql2
+[ci-url]: https://github.com/sidorares/node-mysql2/actions/workflows/ci-coverage.yml?query=branch%3Amaster
+[ci-image]: https://img.shields.io/github/actions/workflow/status/sidorares/node-mysql2/ci-coverage.yml?event=push&style=flat&label=CI&branch=master
+
+# MySQL2
+
+[![NPM Version][npm-image]][npm-url]
+[![NPM Downloads][downloads-image]][downloads-url]
+[![Node.js Version][node-version-image]][node-version-url]
+[![GitHub Workflow Status (with event)][ci-image]][ci-url]
+[![Codecov][coverage]][coverage-url]
+[![License][license-image]][license-url]
+
+[English][docs-base] | [简体中文][docs-base-zh-CN] | [Português (BR)][docs-base-pt-BR]
+
+> MySQL client for Node.js with focus on performance. Supports prepared statements, non-utf8 encodings, binary log protocol, compression, ssl [much more][docs-documentation].
+
+**Table of Contents**
+
+- [History and Why MySQL2](#history-and-why-mysql2)
+- [Installation](#installation)
+- [Documentation](#documentation)
+- [Acknowledgements](#acknowledgements)
+- [Contributing](#contributing)
+
+## History and Why MySQL2
+
+MySQL2 project is a continuation of [MySQL-Native][mysql-native]. Protocol parser code was rewritten from scratch and api changed to match popular [Node MySQL][node-mysql]. MySQL2 team is working together with [Node MySQL][node-mysql] team to factor out shared code and move it under [mysqljs][mysqljs] organization.
+
+MySQL2 is mostly API compatible with [Node MySQL][node-mysql] and supports majority of features. MySQL2 also offers these additional features:
+
+- Faster / Better Performance
+- [Prepared Statements][docs-prepared-statements]
+- MySQL Binary Log Protocol
+- [MySQL Server][docs-mysql-server]
+- Extended support for Encoding and Collation
+- [Promise Wrapper][docs-promise-wrapper]
+- Compression
+- SSL and [Authentication Switch][docs-authentication-switch]
+- [Custom Streams][docs-streams]
+- [Pooling][docs-qs-pooling]
+
+## Installation
+
+MySQL2 is free from native bindings and can be installed on Linux, Mac OS or Windows without any issues.
+
+```bash
+npm install --save mysql2
+```
+
+If you are using TypeScript, you will need to install `@types/node`.
+
+```bash
+npm install --save-dev @types/node
+```
+
+> For TypeScript documentation and examples, see [here][docs-typescript-docs].
+
+## Documentation
+
+- [Quickstart][docs-base]
+  - [First Query][docs-qs-first-query], [Using Prepared Statements][docs-qs-using-prepared-statements], [Using Connection Pools][docs-qs-pooling] and more.
+- [Documentation][docs-documentation]
+- [Examples][docs-examples]
+- [FAQ][docs-faq]
+
+## Acknowledgements
+
+- Internal protocol is written by [@sidorares][sidorares] [MySQL-Native][mysql-native].
+- Constants, SQL parameters interpolation, Pooling, `ConnectionConfig` class taken from [Node MySQL][node-mysql].
+- SSL upgrade code based on [@TooTallNate][TooTallNate] [code][starttls.js].
+- Secure connection / compressed connection api flags compatible to [MariaSQL][node-mariasql] client.
+- [Contributors][contributors].
+
+## Contributing
+
+Want to improve something in **MySQL2**?
+Please check [Contributing.md][contributing] for detailed instruction on how to get started.
+
+To contribute in **MySQL2 Documentation**, please visit the [Website Contributing Guidelines][docs-contributing] for detailed instruction on how to get started.

backend/node_modules/mysql2/index.d.ts

@@ -0,0 +1 @@
+export * from './typings/mysql/index.js';

backend/node_modules/mysql2/index.js

@@ -0,0 +1,77 @@
+'use strict';
+
+const SqlString = require('sql-escaper');
+
+const ConnectionConfig = require('./lib/connection_config.js');
+const parserCache = require('./lib/parsers/parser_cache.js');
+
+const Connection = require('./lib/connection.js');
+
+exports.createConnection = require('./lib/create_connection.js');
+exports.connect = exports.createConnection;
+exports.Connection = Connection;
+exports.ConnectionConfig = ConnectionConfig;
+
+const Pool = require('./lib/pool.js');
+const PoolCluster = require('./lib/pool_cluster.js');
+const createPool = require('./lib/create_pool.js');
+const createPoolCluster = require('./lib/create_pool_cluster.js');
+
+exports.createPool = createPool;
+
+exports.createPoolCluster = createPoolCluster;
+
+exports.createQuery = Connection.createQuery;
+
+exports.Pool = Pool;
+
+exports.PoolCluster = PoolCluster;
+
+exports.createServer = function (handler) {
+  const Server = require('./lib/server.js');
+  const s = new Server();
+  if (handler) {
+    s.on('connection', handler);
+  }
+  return s;
+};
+
+exports.PoolConnection = require('./lib/pool_connection.js');
+exports.authPlugins = require('./lib/auth_plugins');
+exports.escape = SqlString.escape;
+exports.escapeId = SqlString.escapeId;
+exports.format = SqlString.format;
+exports.raw = SqlString.raw;
+
+exports.__defineGetter__(
+  'createConnectionPromise',
+  () => require('./promise.js').createConnection
+);
+
+exports.__defineGetter__(
+  'createPoolPromise',
+  () => require('./promise.js').createPool
+);
+
+exports.__defineGetter__(
+  'createPoolClusterPromise',
+  () => require('./promise.js').createPoolCluster
+);
+
+exports.__defineGetter__('Types', () => require('./lib/constants/types.js'));
+
+exports.__defineGetter__('Charsets', () =>
+  require('./lib/constants/charsets.js')
+);
+
+exports.__defineGetter__('CharsetToEncoding', () =>
+  require('./lib/constants/charset_encodings.js')
+);
+
+exports.setMaxParserCache = function (max) {
+  parserCache.setMaxCache(max);
+};
+
+exports.clearParserCache = function () {
+  parserCache.clearCache();
+};

backend/node_modules/mysql2/lib/auth_41.js

@@ -0,0 +1,95 @@
+'use strict';
+
+/*
+4.1 authentication: (http://bazaar.launchpad.net/~mysql/mysql-server/5.5/view/head:/sql/password.c)
+
+  SERVER:  public_seed=create_random_string()
+           send(public_seed)
+
+  CLIENT:  recv(public_seed)
+           hash_stage1=sha1("password")
+           hash_stage2=sha1(hash_stage1)
+           reply=xor(hash_stage1, sha1(public_seed,hash_stage2)
+
+           // this three steps are done in scramble()
+
+           send(reply)
+
+
+  SERVER:  recv(reply)
+           hash_stage1=xor(reply, sha1(public_seed,hash_stage2))
+           candidate_hash2=sha1(hash_stage1)
+           check(candidate_hash2==hash_stage2)
+
+server stores sha1(sha1(password)) ( hash_stag2)
+*/
+
+const crypto = require('crypto');
+
+function sha1(msg, msg1, msg2) {
+  const hash = crypto.createHash('sha1');
+  hash.update(msg);
+  if (msg1) {
+    hash.update(msg1);
+  }
+
+  if (msg2) {
+    hash.update(msg2);
+  }
+
+  return hash.digest();
+}
+
+function xor(a, b) {
+  const result = Buffer.allocUnsafe(a.length);
+  for (let i = 0; i < a.length; i++) {
+    result[i] = a[i] ^ b[i];
+  }
+  return result;
+}
+
+exports.xor = xor;
+
+function token(password, scramble1, scramble2) {
+  if (!password) {
+    return Buffer.alloc(0);
+  }
+  const stage1 = sha1(password);
+  return exports.calculateTokenFromPasswordSha(stage1, scramble1, scramble2);
+}
+
+exports.calculateTokenFromPasswordSha = function (
+  passwordSha,
+  scramble1,
+  scramble2
+) {
+  // we use AUTH 41 here, and we need only the bytes we just need.
+  const authPluginData1 = scramble1.slice(0, 8);
+  const authPluginData2 = scramble2.slice(0, 12);
+  const stage2 = sha1(passwordSha);
+  const stage3 = sha1(authPluginData1, authPluginData2, stage2);
+  return xor(stage3, passwordSha);
+};
+
+exports.calculateToken = token;
+
+exports.verifyToken = function (publicSeed1, publicSeed2, token, doubleSha) {
+  const hashStage1 = xor(token, sha1(publicSeed1, publicSeed2, doubleSha));
+  const candidateHash2 = sha1(hashStage1);
+  return candidateHash2.compare(doubleSha) === 0;
+};
+
+exports.doubleSha1 = function (password) {
+  return sha1(sha1(password));
+};
+
+function xorRotating(a, seed) {
+  const result = Buffer.allocUnsafe(a.length);
+  const seedLen = seed.length;
+
+  for (let i = 0; i < a.length; i++) {
+    result[i] = a[i] ^ seed[i % seedLen];
+  }
+  return result;
+}
+exports.xorRotating = xorRotating;

backend/node_modules/mysql2/lib/auth_plugins/caching_sha2_password.js

@@ -0,0 +1,115 @@
+'use strict';
+
+// https://mysqlserverteam.com/mysql-8-0-4-new-default-authentication-plugin-caching_sha2_password/
+
+const PLUGIN_NAME = 'caching_sha2_password';
+const crypto = require('crypto');
+const { xor, xorRotating } = require('../auth_41');
+
+const REQUEST_SERVER_KEY_PACKET = Buffer.from([2]);
+const FAST_AUTH_SUCCESS_PACKET = Buffer.from([3]);
+const PERFORM_FULL_AUTHENTICATION_PACKET = Buffer.from([4]);
+
+const STATE_INITIAL = 0;
+const STATE_TOKEN_SENT = 1;
+const STATE_WAIT_SERVER_KEY = 2;
+const STATE_FINAL = -1;
+
+function sha256(msg) {
+  const hash = crypto.createHash('sha256');
+  hash.update(msg);
+  return hash.digest();
+}
+
+function calculateToken(password, scramble) {
+  if (!password) {
+    return Buffer.alloc(0);
+  }
+  const stage1 = sha256(Buffer.from(password));
+  const stage2 = sha256(stage1);
+  const stage3 = sha256(Buffer.concat([stage2, scramble]));
+  return xor(stage1, stage3);
+}
+
+function encrypt(password, scramble, key) {
+  const stage1 = xorRotating(Buffer.from(`${password}\0`, 'utf8'), scramble);
+  return crypto.publicEncrypt(
+    {
+      key,
+      oaepHash: 'sha1',
+      padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
+    },
+    stage1
+  );
+}
+
+const pluginFactory =
+  (pluginOptions = {}) =>
+  ({ connection }) => {
+    let state = 0;
+    let scramble = null;
+
+    const password = connection.config.password;
+
+    const authWithKey = (serverKey) => {
+      const _password = encrypt(password, scramble, serverKey);
+      state = STATE_FINAL;
+      return _password;
+    };
+
+    return (data) => {
+      switch (state) {
+        case STATE_INITIAL:
+          scramble = data.slice(0, 20);
+          state = STATE_TOKEN_SENT;
+          return calculateToken(password, scramble);
+
+        case STATE_TOKEN_SENT:
+          if (FAST_AUTH_SUCCESS_PACKET.equals(data)) {
+            state = STATE_FINAL;
+            return null;
+          }
+
+          if (PERFORM_FULL_AUTHENTICATION_PACKET.equals(data)) {
+            const isSecureConnection =
+              typeof pluginOptions.overrideIsSecure === 'undefined'
+                ? connection.config.ssl || connection.config.socketPath
+                : pluginOptions.overrideIsSecure;
+            if (isSecureConnection) {
+              state = STATE_FINAL;
+              return Buffer.from(`${password}\0`, 'utf8');
+            }
+
+            // if client provides key we can save one extra roundrip on first connection
+            if (pluginOptions.serverPublicKey) {
+              return authWithKey(pluginOptions.serverPublicKey);
+            }
+
+            state = STATE_WAIT_SERVER_KEY;
+            return REQUEST_SERVER_KEY_PACKET;
+          }
+          throw new Error(
+            `Invalid AuthMoreData packet received by ${PLUGIN_NAME} plugin in STATE_TOKEN_SENT state.`
+          );
+        case STATE_WAIT_SERVER_KEY:
+          if (pluginOptions.onServerPublicKey) {
+            pluginOptions.onServerPublicKey(data);
+          }
+          return authWithKey(data);
+        case STATE_FINAL:
+          throw new Error(
+            `Unexpected data in AuthMoreData packet received by ${PLUGIN_NAME} plugin in STATE_FINAL state.`
+          );
+      }
+
+      throw new Error(
+        `Unexpected data in AuthMoreData packet received by ${PLUGIN_NAME} plugin in state ${state}`
+      );
+    };
+  };
+
+// Export the plugin factory as default
+module.exports = pluginFactory;
+
+// Export calculateToken for reuse in initial handshake optimization
+module.exports.calculateToken = calculateToken;

backend/node_modules/mysql2/lib/auth_plugins/caching_sha2_password.md

@@ -0,0 +1,18 @@
+##
+
+https://dev.mysql.com/doc/refman/8.0/en/caching-sha2-pluggable-authentication.html
+
+```js
+const mysql = require('mysql');
+mysql.createConnection({
+  authPlugins: {
+    caching_sha2_password: mysql.authPlugins.caching_sha2_password({
+      onServerPublikKey: function (key) {
+        console.log(key);
+      },
+      serverPublicKey: 'xxxyyy',
+      overrideIsSecure: true, //
+    }),
+  },
+});
+```

backend/node_modules/mysql2/lib/auth_plugins/index.js

@@ -0,0 +1,8 @@
+'use strict';
+
+module.exports = {
+  caching_sha2_password: require('./caching_sha2_password'),
+  mysql_clear_password: require('./mysql_clear_password'),
+  mysql_native_password: require('./mysql_native_password'),
+  sha256_password: require('./sha256_password'),
+};

backend/node_modules/mysql2/lib/auth_plugins/mysql_clear_password.js

@@ -0,0 +1,17 @@
+'use strict';
+
+function bufferFromStr(str) {
+  return Buffer.from(`${str}\0`);
+}
+
+const create_mysql_clear_password_plugin = (pluginOptions) =>
+  function mysql_clear_password_plugin({ connection, command }) {
+    const password =
+      command.password || pluginOptions.password || connection.config.password;
+
+    return function (/* pluginData */) {
+      return bufferFromStr(password);
+    };
+  };
+
+module.exports = create_mysql_clear_password_plugin;

backend/node_modules/mysql2/lib/auth_plugins/mysql_native_password.js

@@ -0,0 +1,34 @@
+'use strict';
+
+//const PLUGIN_NAME = 'mysql_native_password';
+const auth41 = require('../auth_41.js');
+
+module.exports =
+  (pluginOptions) =>
+  ({ connection, command }) => {
+    const password =
+      command.password || pluginOptions.password || connection.config.password;
+    const passwordSha1 =
+      command.passwordSha1 ||
+      pluginOptions.passwordSha1 ||
+      connection.config.passwordSha1;
+    return (data) => {
+      const authPluginData1 = data.slice(0, 8);
+      const authPluginData2 = data.slice(8, 20);
+      let authToken;
+      if (passwordSha1) {
+        authToken = auth41.calculateTokenFromPasswordSha(
+          passwordSha1,
+          authPluginData1,
+          authPluginData2
+        );
+      } else {
+        authToken = auth41.calculateToken(
+          password,
+          authPluginData1,
+          authPluginData2
+        );
+      }
+      return authToken;
+    };
+  };

backend/node_modules/mysql2/lib/auth_plugins/sha256_password.js

@@ -0,0 +1,74 @@
+'use strict';
+
+const PLUGIN_NAME = 'sha256_password';
+const crypto = require('crypto');
+const { xorRotating } = require('../auth_41');
+const Tls = require('tls');
+
+const REQUEST_SERVER_KEY_PACKET = Buffer.from([1]);
+
+const STATE_INITIAL = 0;
+const STATE_WAIT_SERVER_KEY = 1;
+const STATE_FINAL = -1;
+
+function encrypt(password, scramble, key) {
+  const stage1 = xorRotating(Buffer.from(`${password}\0`, 'utf8'), scramble);
+  return crypto.publicEncrypt(
+    {
+      key,
+      oaepHash: 'sha1',
+    },
+    stage1
+  );
+}
+
+module.exports =
+  (pluginOptions = {}) =>
+  ({ connection }) => {
+    let state = 0;
+    let scramble = null;
+
+    const password = connection.config.password;
+
+    const authWithKey = (serverKey) => {
+      const _password = encrypt(password, scramble, serverKey);
+      state = STATE_FINAL;
+      return _password;
+    };
+
+    return (data) => {
+      switch (state) {
+        case STATE_INITIAL:
+          if (
+            connection.stream instanceof Tls.TLSSocket &&
+            connection.stream.encrypted === true
+          ) {
+            // We don't need to encrypt passwords over TLS connection
+            return Buffer.from(`${password}\0`, 'utf8');
+          }
+
+          scramble = data.slice(0, 20);
+          // if client provides key we can save one extra roundrip on first connection
+          if (pluginOptions.serverPublicKey) {
+            return authWithKey(pluginOptions.serverPublicKey);
+          }
+
+          state = STATE_WAIT_SERVER_KEY;
+          return REQUEST_SERVER_KEY_PACKET;
+
+        case STATE_WAIT_SERVER_KEY:
+          if (pluginOptions.onServerPublicKey) {
+            pluginOptions.onServerPublicKey(data);
+          }
+          return authWithKey(data);
+        case STATE_FINAL:
+          throw new Error(
+            `Unexpected data in AuthMoreData packet received by ${PLUGIN_NAME} plugin in STATE_FINAL state.`
+          );
+      }
+
+      throw new Error(
+        `Unexpected data in AuthMoreData packet received by ${PLUGIN_NAME} plugin in state ${state}`
+      );
+    };
+  };

backend/node_modules/mysql2/lib/base/pool.js

@@ -0,0 +1,347 @@
+'use strict';
+
+const process = require('process');
+const SqlString = require('sql-escaper');
+const EventEmitter = require('events').EventEmitter;
+const PoolConnection = require('../pool_connection.js');
+const Queue = require('denque');
+const BaseConnection = require('./connection.js');
+const Errors = require('../constants/errors.js');
+const {
+  traceCallback,
+  getServerContext,
+  poolConnectChannel,
+} = require('../tracing.js');
+
+// Source: https://github.com/go-sql-driver/mysql/blob/76c00e35a8d48f8f70f0e7dffe584692bd3fa612/packets.go#L598-L613
+function isReadOnlyError(err) {
+  if (!err || !err.errno) {
+    return false;
+  }
+  // 1792: ER_CANT_EXECUTE_IN_READ_ONLY_TRANSACTION
+  // 1290: ER_OPTION_PREVENTS_STATEMENT (returned by Aurora during failover)
+  // 1836: ER_READ_ONLY_MODE
+  return (
+    err.errno === Errors.ER_OPTION_PREVENTS_STATEMENT ||
+    err.errno === Errors.ER_CANT_EXECUTE_IN_READ_ONLY_TRANSACTION ||
+    err.errno === Errors.ER_READ_ONLY_MODE
+  );
+}
+
+function spliceConnection(queue, connection) {
+  const len = queue.length;
+  for (let i = 0; i < len; i++) {
+    if (queue.get(i) === connection) {
+      queue.removeOne(i);
+      break;
+    }
+  }
+}
+
+class BasePool extends EventEmitter {
+  constructor(options) {
+    super();
+    this.config = options.config;
+    this.config.connectionConfig.pool = this;
+    this._allConnections = new Queue();
+    this._freeConnections = new Queue();
+    this._connectionQueue = new Queue();
+    this._closed = false;
+    if (this.config.maxIdle < this.config.connectionLimit) {
+      // create idle connection timeout automatically release job
+      this._removeIdleTimeoutConnections();
+    }
+  }
+
+  getConnection(cb) {
+    const _getConnection = (cb) => {
+      if (this._closed) {
+        return process.nextTick(() => cb(new Error('Pool is closed.')));
+      }
+      let connection;
+      if (this._freeConnections.length > 0) {
+        connection = this._freeConnections.pop();
+        this.emit('acquire', connection);
+        return process.nextTick(() => {
+          connection._released = false;
+          cb(null, connection);
+        });
+      }
+      if (
+        this.config.connectionLimit === 0 ||
+        this._allConnections.length < this.config.connectionLimit
+      ) {
+        connection = new PoolConnection(this, {
+          config: this.config.connectionConfig,
+        });
+        this._allConnections.push(connection);
+        return connection.connect((err) => {
+          if (this._closed) {
+            return cb(new Error('Pool is closed.'));
+          }
+          if (err) {
+            return cb(err);
+          }
+          this.emit('connection', connection);
+          this.emit('acquire', connection);
+          return cb(null, connection);
+        });
+      }
+      if (!this.config.waitForConnections) {
+        return process.nextTick(() =>
+          cb(new Error('No connections available.'))
+        );
+      }
+      if (
+        this.config.queueLimit &&
+        this._connectionQueue.length >= this.config.queueLimit
+      ) {
+        return cb(new Error('Queue limit reached.'));
+      }
+      this.emit('enqueue');
+      return this._connectionQueue.push(cb);
+    };
+    const config = this.config.connectionConfig;
+    traceCallback(
+      poolConnectChannel,
+      _getConnection,
+      0,
+      () => {
+        const server = getServerContext(config);
+        return {
+          database: config.database || '',
+          serverAddress: server.serverAddress,
+          serverPort: server.serverPort,
+        };
+      },
+      null,
+      cb
+    );
+  }
+
+  releaseConnection(connection) {
+    let cb;
+    if (!connection._pool) {
+      // The connection has been removed from the pool and is no longer good.
+      if (this._connectionQueue.length) {
+        cb = this._connectionQueue.shift();
+        process.nextTick(this.getConnection.bind(this, cb));
+      }
+      return;
+    }
+
+    // Reset connection state if configured
+    if (this.config.resetOnRelease && connection.reset) {
+      connection.reset((err) => {
+        if (err) {
+          // If reset fails, remove connection from pool
+          connection._pool = null;
+          spliceConnection(this._allConnections, connection);
+          connection.destroy();
+
+          // Try to create a new connection for waiting callbacks
+          if (this._connectionQueue.length) {
+            cb = this._connectionQueue.shift();
+            process.nextTick(this.getConnection.bind(this, cb));
+          }
+          return;
+        }
+
+        // Reset successful, continue with normal release flow
+        this._handleSuccessfulRelease(connection);
+      });
+    } else {
+      this._handleSuccessfulRelease(connection);
+    }
+  }
+
+  _handleSuccessfulRelease(connection) {
+    let cb;
+    if (this._connectionQueue.length) {
+      cb = this._connectionQueue.shift();
+      process.nextTick(() => {
+        connection._released = false;
+        cb(null, connection);
+      });
+    } else {
+      this._freeConnections.push(connection);
+      this.emit('release', connection);
+    }
+  }
+
+  [Symbol.dispose]() {
+    if (!this._closed) {
+      this.end();
+    }
+  }
+
+  end(cb) {
+    this._closed = true;
+    clearTimeout(this._removeIdleTimeoutConnectionsTimer);
+    if (typeof cb !== 'function') {
+      cb = function (err) {
+        if (err) {
+          throw err;
+        }
+      };
+    }
+    while (this._connectionQueue.length > 0) {
+      const queuedCallback = this._connectionQueue.shift();
+      process.nextTick(() => queuedCallback(new Error('Pool is closed.')));
+    }
+    let calledBack = false;
+    let closedConnections = 0;
+    let connection;
+    const endCB = function (err) {
+      if (calledBack) {
+        return;
+      }
+      if (err || ++closedConnections >= this._allConnections.length) {
+        calledBack = true;
+        cb(err);
+        return;
+      }
+    }.bind(this);
+    if (this._allConnections.length === 0) {
+      endCB();
+      return;
+    }
+    for (let i = 0; i < this._allConnections.length; i++) {
+      connection = this._allConnections.get(i);
+      connection._realEnd(endCB);
+    }
+  }
+
+  query(sql, values, cb) {
+    const cmdQuery = BaseConnection.createQuery(
+      sql,
+      values,
+      cb,
+      this.config.connectionConfig
+    );
+    if (typeof cmdQuery.namedPlaceholders === 'undefined') {
+      cmdQuery.namedPlaceholders =
+        this.config.connectionConfig.namedPlaceholders;
+    }
+    this.getConnection((err, conn) => {
+      if (err) {
+        if (typeof cmdQuery.onResult === 'function') {
+          cmdQuery.onResult(err);
+        } else {
+          cmdQuery.emit('error', err);
+        }
+        return;
+      }
+      try {
+        let queryError = null;
+        const origOnResult = cmdQuery.onResult;
+        if (origOnResult) {
+          cmdQuery.onResult = function (err, rows, fields) {
+            queryError = err || null;
+            origOnResult(err, rows, fields);
+          };
+        } else {
+          cmdQuery.once('error', (err) => {
+            queryError = err;
+          });
+        }
+        conn.query(cmdQuery).once('end', () => {
+          if (isReadOnlyError(queryError)) {
+            conn.destroy();
+          } else {
+            conn.release();
+          }
+        });
+      } catch (e) {
+        conn.release();
+        throw e;
+      }
+    });
+    return cmdQuery;
+  }
+
+  execute(sql, values, cb) {
+    // TODO construct execute command first here and pass it to connection.execute
+    // so that polymorphic arguments logic is there in one place
+    if (typeof values === 'function') {
+      cb = values;
+      values = [];
+    }
+    this.getConnection((err, conn) => {
+      if (err) {
+        return cb(err);
+      }
+      try {
+        conn
+          .execute(sql, values, (err, rows, fields) => {
+            if (isReadOnlyError(err)) {
+              conn.destroy();
+            }
+            cb(err, rows, fields);
+          })
+          .once('end', () => {
+            conn.release();
+          });
+      } catch (e) {
+        conn.release();
+        return cb(e);
+      }
+    });
+  }
+
+  _removeConnection(connection) {
+    // Remove connection from all connections
+    spliceConnection(this._allConnections, connection);
+    // Remove connection from free connections
+    spliceConnection(this._freeConnections, connection);
+    this.releaseConnection(connection);
+  }
+
+  _removeIdleTimeoutConnections() {
+    if (this._removeIdleTimeoutConnectionsTimer) {
+      clearTimeout(this._removeIdleTimeoutConnectionsTimer);
+    }
+
+    this._removeIdleTimeoutConnectionsTimer = setTimeout(() => {
+      try {
+        while (
+          this._freeConnections.length > this.config.maxIdle ||
+          (this._freeConnections.length > 0 &&
+            Date.now() - this._freeConnections.get(0).lastActiveTime >
+              this.config.idleTimeout)
+        ) {
+          if (this.config.connectionConfig.gracefulEnd) {
+            this._freeConnections.get(0).end();
+          } else {
+            this._freeConnections.get(0).destroy();
+          }
+        }
+      } finally {
+        this._removeIdleTimeoutConnections();
+      }
+    }, 1000);
+  }
+
+  format(sql, values) {
+    return SqlString.format(
+      sql,
+      values,
+      this.config.connectionConfig.stringifyObjects,
+      this.config.connectionConfig.timezone
+    );
+  }
+
+  escape(value) {
+    return SqlString.escape(
+      value,
+      this.config.connectionConfig.stringifyObjects,
+      this.config.connectionConfig.timezone
+    );
+  }
+
+  escapeId(value) {
+    return SqlString.escapeId(value, false);
+  }
+}
+
+module.exports = BasePool;

backend/node_modules/mysql2/lib/commands/auth_switch.js

@@ -0,0 +1,151 @@
+// This file was modified by Oracle on July 5, 2021.
+// Errors generated by asynchronous authentication plugins are now being
+// handled and subsequently emitted at the command level.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+const Packets = require('../packets/index.js');
+const sha256_password = require('../auth_plugins/sha256_password');
+const caching_sha2_password = require('../auth_plugins/caching_sha2_password.js');
+const mysql_native_password = require('../auth_plugins/mysql_native_password.js');
+const mysql_clear_password = require('../auth_plugins/mysql_clear_password.js');
+
+// Use Object.create(null) to avoid prototype pollution
+// This prevents server-controlled pluginName values like "toString" or "__proto__"
+// from resolving to prototype properties
+const standardAuthPlugins = Object.assign(Object.create(null), {
+  sha256_password: sha256_password({}),
+  caching_sha2_password: caching_sha2_password({}),
+  mysql_native_password: mysql_native_password({}),
+  mysql_clear_password: mysql_clear_password({}),
+});
+
+// Helper function to get auth plugin (custom or standard)
+function getAuthPlugin(pluginName, connection) {
+  const customPlugins = connection.config.authPlugins;
+
+  // Check custom plugins with hasOwnProperty for safety
+  if (
+    customPlugins &&
+    Object.prototype.hasOwnProperty.call(customPlugins, pluginName)
+  ) {
+    return customPlugins[pluginName];
+  }
+
+  // Safe to access standardAuthPlugins directly since it has no prototype
+  return standardAuthPlugins[pluginName];
+}
+
+function warnLegacyAuthSwitch() {
+  console.warn(
+    'WARNING! authSwitchHandler api is deprecated, please use new authPlugins api'
+  );
+}
+
+function authSwitchPluginError(error, command) {
+  // Authentication errors are fatal
+  error.code = 'AUTH_SWITCH_PLUGIN_ERROR';
+  error.fatal = true;
+
+  command.emit('error', error);
+}
+
+function authSwitchRequest(packet, connection, command) {
+  const { pluginName, pluginData } =
+    Packets.AuthSwitchRequest.fromPacket(packet);
+
+  // legacy plugin api don't allow to override mysql_native_password
+  // if pluginName is mysql_native_password it's using standard auth4.1 auth
+  if (
+    connection.config.authSwitchHandler &&
+    pluginName !== 'mysql_native_password'
+  ) {
+    const legacySwitchHandler = connection.config.authSwitchHandler;
+    warnLegacyAuthSwitch();
+    legacySwitchHandler({ pluginName, pluginData }, (err, data) => {
+      if (err) {
+        return authSwitchPluginError(err, command);
+      }
+      connection.writePacket(new Packets.AuthSwitchResponse(data).toPacket());
+    });
+    return;
+  }
+
+  if (pluginName === 'mysql_clear_password') {
+    const hasCustomPlugin =
+      connection.config.authPlugins &&
+      Object.prototype.hasOwnProperty.call(
+        connection.config.authPlugins,
+        'mysql_clear_password'
+      );
+    if (!hasCustomPlugin && !connection.config.enableCleartextPlugin) {
+      const err = new Error(
+        'Server requested authentication using mysql_clear_password, ' +
+          'which sends the password in plaintext over the network and is ' +
+          'disabled by default. To enable it, set the `enableCleartextPlugin` ' +
+          'option to `true` in your connection configuration, or provide a ' +
+          'custom `mysql_clear_password` auth plugin via the `authPlugins` ' +
+          'option. Only use this over a secure connection (TLS/SSL).'
+      );
+      err.code = 'MYSQL_CLEAR_PASSWORD_NOT_ENABLED';
+      err.fatal = true;
+      throw err;
+    }
+  }
+
+  const authPlugin = getAuthPlugin(pluginName, connection);
+  if (!authPlugin) {
+    throw new Error(
+      `Server requests authentication using unknown plugin ${pluginName}. See ${'TODO: add plugins doco here'} on how to configure or author authentication plugins.`
+    );
+  }
+  connection._authPlugin = authPlugin({ connection, command });
+  Promise.resolve(connection._authPlugin(pluginData))
+    .then((data) => {
+      if (data) {
+        connection.writePacket(new Packets.AuthSwitchResponse(data).toPacket());
+      }
+    })
+    .catch((err) => {
+      authSwitchPluginError(err, command);
+    });
+}
+
+function authSwitchRequestMoreData(packet, connection, command) {
+  const { data } = Packets.AuthSwitchRequestMoreData.fromPacket(packet);
+
+  if (connection.config.authSwitchHandler) {
+    const legacySwitchHandler = connection.config.authSwitchHandler;
+    warnLegacyAuthSwitch();
+    legacySwitchHandler({ pluginData: data }, (err, data) => {
+      if (err) {
+        return authSwitchPluginError(err, command);
+      }
+      connection.writePacket(new Packets.AuthSwitchResponse(data).toPacket());
+    });
+    return;
+  }
+
+  if (!connection._authPlugin) {
+    throw new Error(
+      'AuthPluginMoreData received but no auth plugin instance found'
+    );
+  }
+  Promise.resolve(connection._authPlugin(data))
+    .then((data) => {
+      if (data) {
+        connection.writePacket(new Packets.AuthSwitchResponse(data).toPacket());
+      }
+    })
+    .catch((err) => {
+      authSwitchPluginError(err, command);
+    });
+}
+
+module.exports = {
+  authSwitchRequest,
+  authSwitchRequestMoreData,
+  getAuthPlugin,
+  standardAuthPlugins,
+};

backend/node_modules/mysql2/lib/commands/binlog_dump.js

@@ -0,0 +1,109 @@
+'use strict';
+
+const Command = require('./command');
+const Packets = require('../packets');
+
+const eventParsers = [];
+
+class BinlogEventHeader {
+  constructor(packet) {
+    this.timestamp = packet.readInt32();
+    this.eventType = packet.readInt8();
+    this.serverId = packet.readInt32();
+    this.eventSize = packet.readInt32();
+    this.logPos = packet.readInt32();
+    this.flags = packet.readInt16();
+  }
+}
+
+class BinlogDump extends Command {
+  constructor(opts) {
+    super();
+    // this.onResult = callback;
+    this.opts = opts;
+  }
+
+  start(packet, connection) {
+    const newPacket = new Packets.BinlogDump(this.opts);
+    connection.writePacket(newPacket.toPacket(1));
+    return BinlogDump.prototype.binlogData;
+  }
+
+  binlogData(packet) {
+    // ok - continue consuming events
+    // error - error
+    // eof - end of binlog
+    if (packet.isEOF()) {
+      this.emit('eof');
+      return null;
+    }
+    // binlog event header
+    packet.readInt8();
+    const header = new BinlogEventHeader(packet);
+    const EventParser = eventParsers[header.eventType];
+    let event;
+    if (EventParser) {
+      event = new EventParser(packet);
+    } else {
+      event = {
+        name: 'UNKNOWN',
+      };
+    }
+    event.header = header;
+    this.emit('event', event);
+    return BinlogDump.prototype.binlogData;
+  }
+}
+
+class RotateEvent {
+  constructor(packet) {
+    this.pposition = packet.readInt32();
+    // TODO: read uint64 here
+    packet.readInt32(); // positionDword2
+    this.nextBinlog = packet.readString();
+    this.name = 'RotateEvent';
+  }
+}
+
+class FormatDescriptionEvent {
+  constructor(packet) {
+    this.binlogVersion = packet.readInt16();
+    this.serverVersion = packet.readString(50).replace(/\u0000.*/, ''); // eslint-disable-line no-control-regex
+    this.createTimestamp = packet.readInt32();
+    this.eventHeaderLength = packet.readInt8(); // should be 19
+    this.eventsLength = packet.readBuffer();
+    this.name = 'FormatDescriptionEvent';
+  }
+}
+
+class QueryEvent {
+  constructor(packet) {
+    const parseStatusVars = require('../packets/binlog_query_statusvars.js');
+    this.slaveProxyId = packet.readInt32();
+    this.executionTime = packet.readInt32();
+    const schemaLength = packet.readInt8();
+    this.errorCode = packet.readInt16();
+    const statusVarsLength = packet.readInt16();
+    const statusVars = packet.readBuffer(statusVarsLength);
+    this.schema = packet.readString(schemaLength);
+    packet.readInt8(); // should be zero
+    this.statusVars = parseStatusVars(statusVars);
+    this.query = packet.readString();
+    this.name = 'QueryEvent';
+  }
+}
+
+class XidEvent {
+  constructor(packet) {
+    this.binlogVersion = packet.readInt16();
+    this.xid = packet.readInt64();
+    this.name = 'XidEvent';
+  }
+}
+
+eventParsers[2] = QueryEvent;
+eventParsers[4] = RotateEvent;
+eventParsers[15] = FormatDescriptionEvent;
+eventParsers[16] = XidEvent;
+
+module.exports = BinlogDump;

backend/node_modules/mysql2/lib/commands/change_user.js

@@ -0,0 +1,68 @@
+// This file was modified by Oracle on September 21, 2021.
+// The changes involve saving additional authentication factor passwords
+// in the command scope and enabling multi-factor authentication in the
+// client-side when the server supports it.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+const Command = require('./command.js');
+const Packets = require('../packets/index.js');
+const ClientConstants = require('../constants/client');
+const ClientHandshake = require('./client_handshake.js');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+
+class ChangeUser extends Command {
+  constructor(options, callback) {
+    super();
+    this.onResult = callback;
+    this.user = options.user;
+    this.password = options.password;
+    // "password1" is an alias of "password"
+    this.password1 = options.password;
+    this.password2 = options.password2;
+    this.password3 = options.password3;
+    this.database = options.database;
+    this.passwordSha1 = options.passwordSha1;
+    this.charsetNumber = options.charsetNumber;
+    this.currentConfig = options.currentConfig;
+    this.authenticationFactor = 0;
+  }
+  start(packet, connection) {
+    const newPacket = new Packets.ChangeUser({
+      flags: connection.config.clientFlags,
+      user: this.user,
+      database: this.database,
+      charsetNumber: this.charsetNumber,
+      password: this.password,
+      passwordSha1: this.passwordSha1,
+      authPluginData1: connection._handshakePacket.authPluginData1,
+      authPluginData2: connection._handshakePacket.authPluginData2,
+    });
+    this.currentConfig.user = this.user;
+    this.currentConfig.password = this.password;
+    this.currentConfig.database = this.database;
+    this.currentConfig.charsetNumber = this.charsetNumber;
+    connection.clientEncoding = CharsetToEncoding[this.charsetNumber];
+    // clear prepared statements cache as all statements become invalid after changeUser
+    connection._statements.clear();
+    connection.writePacket(newPacket.toPacket());
+    // check if the server supports multi-factor authentication
+    const multiFactorAuthentication =
+      connection.serverCapabilityFlags &
+      ClientConstants.MULTI_FACTOR_AUTHENTICATION;
+    if (multiFactorAuthentication) {
+      // if the server supports multi-factor authentication, we enable it in
+      // the client
+      this.authenticationFactor = 1;
+    }
+    return ChangeUser.prototype.handshakeResult;
+  }
+}
+
+ChangeUser.prototype.handshakeResult =
+  ClientHandshake.prototype.handshakeResult;
+ChangeUser.prototype.calculateNativePasswordAuthToken =
+  ClientHandshake.prototype.calculateNativePasswordAuthToken;
+
+module.exports = ChangeUser;

backend/node_modules/mysql2/lib/commands/client_handshake.js

@@ -0,0 +1,386 @@
+// This file was modified by Oracle on June 17, 2021.
+// Handshake errors are now maked as fatal and the corresponding events are
+// emitted in the command instance itself.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+// This file was modified by Oracle on September 21, 2021.
+// Handshake workflow now supports additional authentication factors requested
+// by the server.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+const Command = require('./command.js');
+const Packets = require('../packets/index.js');
+const ClientConstants = require('../constants/client.js');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+const auth41 = require('../auth_41.js');
+const { getAuthPlugin } = require('./auth_switch.js');
+const {
+  calculateToken: calculateSha2Token,
+} = require('../auth_plugins/caching_sha2_password.js');
+
+function flagNames(flags) {
+  const res = [];
+  for (const c in ClientConstants) {
+    if (flags & ClientConstants[c]) {
+      res.push(c.replace(/_/g, ' ').toLowerCase());
+    }
+  }
+  return res;
+}
+
+class ClientHandshake extends Command {
+  constructor(clientFlags) {
+    super();
+    this.handshake = null;
+    this.clientFlags = clientFlags;
+    this.authenticationFactor = 0;
+  }
+
+  start() {
+    return ClientHandshake.prototype.handshakeInit;
+  }
+
+  sendSSLRequest(connection) {
+    const sslRequest = new Packets.SSLRequest(
+      this.clientFlags,
+      connection.config.charsetNumber
+    );
+    connection.writePacket(sslRequest.toPacket());
+  }
+
+  sendCredentials(connection) {
+    if (connection.config.debug) {
+      console.log(
+        'Sending handshake packet: flags:%d=(%s)',
+        this.clientFlags,
+        flagNames(this.clientFlags).join(', ')
+      );
+    }
+    this.user = connection.config.user;
+    this.password = connection.config.password;
+    // "password1" is an alias to the original "password" value
+    // to make it easier to integrate multi-factor authentication
+    this.password1 = connection.config.password;
+    // "password2" and "password3" are the 2nd and 3rd factor authentication
+    // passwords, which can be undefined depending on the authentication
+    // plugin being used
+    this.password2 = connection.config.password2;
+    this.password3 = connection.config.password3;
+    this.passwordSha1 = connection.config.passwordSha1;
+    this.database = connection.config.database;
+    this.authPluginName = this.handshake.authPluginName;
+
+    // Optimization: Try to use the server's preferred authentication method
+    // to avoid an unnecessary auth switch roundtrip
+    const serverAuthMethod = this.handshake.authPluginName;
+    const isSecureConnection =
+      connection.config.ssl || connection.config.socketPath;
+
+    // Combine auth plugin data for easier handling
+    // Note: authPluginData2 can include a trailing NUL byte when PLUGIN_AUTH is set
+    // We must ensure exactly 20 bytes for the scramble
+    const authPluginData =
+      this.handshake.authPluginData1 && this.handshake.authPluginData2
+        ? Buffer.concat([
+            this.handshake.authPluginData1,
+            this.handshake.authPluginData2,
+          ]).slice(0, 20)
+        : Buffer.alloc(20);
+
+    // Check if user has custom auth plugin or legacy handler for the server-advertised method
+    // If so, we must not bypass the auth switch flow with our built-in implementation
+    const hasCustomAuthPlugin =
+      connection.config.authPlugins &&
+      Object.prototype.hasOwnProperty.call(
+        connection.config.authPlugins,
+        serverAuthMethod
+      );
+    const hasLegacyAuthSwitchHandler =
+      typeof connection.config.authSwitchHandler === 'function';
+
+    // Determine which auth method to use
+    // Try to use server's preferred method if we can, otherwise fallback to native
+    const canUseDirectAuth =
+      !hasCustomAuthPlugin &&
+      !hasLegacyAuthSwitchHandler &&
+      this.canUseAuthMethodDirectly(serverAuthMethod, isSecureConnection) &&
+      (serverAuthMethod !== 'mysql_clear_password' ||
+        connection.config.enableCleartextPlugin);
+
+    const clientAuthMethod = canUseDirectAuth
+      ? serverAuthMethod
+      : 'mysql_native_password';
+
+    // Calculate the auth token for the chosen method
+    const authToken = this.calculateAuthToken(
+      clientAuthMethod,
+      this.password,
+      authPluginData
+    );
+
+    if (connection.config.debug) {
+      console.log(
+        'Server auth method: %s, Using auth method: %s',
+        serverAuthMethod,
+        clientAuthMethod
+      );
+    }
+
+    const handshakeResponse = new Packets.HandshakeResponse({
+      flags: this.clientFlags,
+      user: this.user,
+      database: this.database,
+      password: this.password,
+      passwordSha1: this.passwordSha1,
+      charsetNumber: connection.config.charsetNumber,
+      authPluginData1: this.handshake.authPluginData1,
+      authPluginData2: this.handshake.authPluginData2,
+      compress: connection.config.compress,
+      connectAttributes: connection.config.connectAttributes,
+      authToken: authToken,
+      authPluginName: clientAuthMethod,
+    });
+    connection.writePacket(handshakeResponse.toPacket());
+
+    // If we used a non-native auth method in the initial handshake response,
+    // we need to prepare for potential AuthMoreData packets by creating
+    // the appropriate auth plugin instance
+    if (clientAuthMethod !== 'mysql_native_password') {
+      this.initializeAuthPlugin(clientAuthMethod, authPluginData, connection);
+    }
+  }
+
+  calculateNativePasswordAuthToken(authPluginData) {
+    // TODO: dont split into authPluginData1 and authPluginData2, instead join when 1 & 2 received
+    const authPluginData1 = authPluginData.slice(0, 8);
+    const authPluginData2 = authPluginData.slice(8, 20);
+    let authToken;
+    if (this.passwordSha1) {
+      authToken = auth41.calculateTokenFromPasswordSha(
+        this.passwordSha1,
+        authPluginData1,
+        authPluginData2
+      );
+    } else {
+      authToken = auth41.calculateToken(
+        this.password,
+        authPluginData1,
+        authPluginData2
+      );
+    }
+    return authToken;
+  }
+
+  calculateSha256Token(password, scramble) {
+    // Reuse the token calculation from caching_sha2_password plugin
+    // to avoid code duplication and ensure consistency
+    return calculateSha2Token(password, scramble);
+  }
+
+  // Helper: Calculate auth token for a specific auth method
+  calculateAuthToken(authMethod, password, authPluginData) {
+    switch (authMethod) {
+      case 'mysql_native_password':
+        return this.calculateNativePasswordAuthToken(authPluginData);
+
+      case 'caching_sha2_password':
+        return this.calculateSha256Token(password, authPluginData);
+
+      case 'sha256_password':
+      case 'mysql_clear_password':
+        // These methods send plaintext password over secure connections
+        return password
+          ? Buffer.from(`${password}\0`, 'utf8')
+          : Buffer.alloc(0);
+
+      default:
+        // Unknown method - use native password as fallback
+        return this.calculateNativePasswordAuthToken(authPluginData);
+    }
+  }
+
+  // Helper: Determine if we can use a specific auth method directly
+  canUseAuthMethodDirectly(authMethod, isSecureConnection) {
+    switch (authMethod) {
+      case 'mysql_native_password':
+      case 'caching_sha2_password':
+        // These methods work with or without SSL
+        return true;
+
+      case 'sha256_password':
+      case 'mysql_clear_password':
+        // These methods require secure connection for direct use
+        return isSecureConnection;
+
+      default:
+        // Unknown methods - fallback to native password
+        return false;
+    }
+  }
+
+  // Helper: Initialize auth plugin for handling subsequent AuthMoreData packets
+  initializeAuthPlugin(authMethod, authPluginData, connection) {
+    const authPlugin = getAuthPlugin(authMethod, connection);
+    if (!authPlugin) {
+      return; // Plugin not found, will fallback to auth switch if needed
+    }
+
+    // Initialize the plugin with connection and command context
+    const pluginHandler = authPlugin({ connection, command: this });
+    connection._authPlugin = pluginHandler;
+
+    // Prime the plugin by calling it with the scramble data
+    // This advances the plugin's state machine (e.g., to STATE_TOKEN_SENT)
+    // We don't send the result because we already included it in the handshake response
+    try {
+      Promise.resolve(pluginHandler(authPluginData)).catch((err) => {
+        // Ignore errors during initialization since we already sent the token
+        if (connection.config.debug) {
+          console.log('Auth plugin initialization:', err.message);
+        }
+      });
+    } catch (err) {
+      // Ignore synchronous errors during initialization
+      if (connection.config.debug) {
+        console.log('Auth plugin initialization error:', err.message);
+      }
+    }
+  }
+
+  handshakeInit(helloPacket, connection) {
+    this.on('error', (e) => {
+      connection._fatalError = e;
+      connection._protocolError = e;
+    });
+    this.handshake = Packets.Handshake.fromPacket(helloPacket);
+    if (connection.config.debug) {
+      console.log(
+        'Server hello packet: capability flags:%d=(%s)',
+        this.handshake.capabilityFlags,
+        flagNames(this.handshake.capabilityFlags).join(', ')
+      );
+    }
+    connection.serverCapabilityFlags = this.handshake.capabilityFlags;
+    connection.serverEncoding = CharsetToEncoding[this.handshake.characterSet];
+    connection.connectionId = this.handshake.connectionId;
+    const serverSSLSupport =
+      this.handshake.capabilityFlags & ClientConstants.SSL;
+    // multi factor authentication is enabled with the
+    // "MULTI_FACTOR_AUTHENTICATION" capability and should only be used if it
+    // is supported by the server
+    const multiFactorAuthentication =
+      this.handshake.capabilityFlags &
+      ClientConstants.MULTI_FACTOR_AUTHENTICATION;
+    this.clientFlags = this.clientFlags | multiFactorAuthentication;
+    // use compression only if requested by client and supported by server
+    connection.config.compress =
+      connection.config.compress &&
+      this.handshake.capabilityFlags & ClientConstants.COMPRESS;
+    this.clientFlags = this.clientFlags | connection.config.compress;
+    if (connection.config.ssl) {
+      // client requires SSL but server does not support it
+      if (!serverSSLSupport) {
+        const err = new Error('Server does not support secure connection');
+        err.code = 'HANDSHAKE_NO_SSL_SUPPORT';
+        err.fatal = true;
+        this.emit('error', err);
+        return false;
+      }
+      // send ssl upgrade request and immediately upgrade connection to secure
+      this.clientFlags |= ClientConstants.SSL;
+      this.sendSSLRequest(connection);
+      connection.startTLS((err) => {
+        // after connection is secure
+        if (err) {
+          // SSL negotiation error are fatal
+          err.code = 'HANDSHAKE_SSL_ERROR';
+          err.fatal = true;
+          this.emit('error', err);
+          return;
+        }
+        // rest of communication is encrypted
+        this.sendCredentials(connection);
+      });
+    } else {
+      this.sendCredentials(connection);
+    }
+    if (multiFactorAuthentication) {
+      // if the server supports multi-factor authentication, we enable it in
+      // the client
+      this.authenticationFactor = 1;
+    }
+    return ClientHandshake.prototype.handshakeResult;
+  }
+
+  handshakeResult(packet, connection) {
+    const marker = packet.peekByte();
+    // packet can be OK_Packet, ERR_Packet, AuthSwitchRequest, AuthNextFactor
+    // or AuthMoreData
+    if (marker === 0xfe || marker === 1 || marker === 0x02) {
+      const authSwitch = require('./auth_switch');
+      try {
+        if (marker === 1) {
+          authSwitch.authSwitchRequestMoreData(packet, connection, this);
+        } else {
+          // if authenticationFactor === 0, it means the server does not support
+          // the multi-factor authentication capability
+          if (this.authenticationFactor !== 0) {
+            // if we are past the first authentication factor, we should use the
+            // corresponding password (if there is one)
+            connection.config.password =
+              this[`password${this.authenticationFactor}`];
+            // update the current authentication factor
+            this.authenticationFactor += 1;
+          }
+          // if marker === 0x02, it means it is an AuthNextFactor packet,
+          // which is similar in structure to an AuthSwitchRequest packet,
+          // so, we can use it directly
+          authSwitch.authSwitchRequest(packet, connection, this);
+        }
+        return ClientHandshake.prototype.handshakeResult;
+      } catch (err) {
+        if (!err.code) {
+          err.code = 'AUTH_SWITCH_PLUGIN_ERROR';
+        }
+        err.fatal = true;
+
+        if (this.onResult) {
+          this.onResult(err);
+        } else {
+          this.emit('error', err);
+        }
+        return null;
+      }
+    }
+    if (marker !== 0) {
+      const err = new Error('Unexpected packet during handshake phase');
+      // Unknown handshake errors are fatal
+      err.code = 'HANDSHAKE_UNKNOWN_ERROR';
+      err.fatal = true;
+
+      if (this.onResult) {
+        this.onResult(err);
+      } else {
+        this.emit('error', err);
+      }
+      return null;
+    }
+    // this should be called from ClientHandshake command only
+    // and skipped when called from ChangeUser command
+    if (!connection.authorized) {
+      connection.authorized = true;
+      if (connection.config.compress) {
+        const enableCompression =
+          require('../compressed_protocol.js').enableCompression;
+        enableCompression(connection);
+      }
+    }
+    if (this.onResult) {
+      this.onResult(null);
+    }
+    return null;
+  }
+}
+module.exports = ClientHandshake;

backend/node_modules/mysql2/lib/commands/close_statement.js

@@ -0,0 +1,18 @@
+'use strict';
+
+const Command = require('./command');
+const Packets = require('../packets/index.js');
+
+class CloseStatement extends Command {
+  constructor(id) {
+    super();
+    this.id = id;
+  }
+
+  start(packet, connection) {
+    connection.writePacket(new Packets.CloseStatement(this.id).toPacket(1));
+    return null;
+  }
+}
+
+module.exports = CloseStatement;

backend/node_modules/mysql2/lib/commands/command.js

@@ -0,0 +1,54 @@
+'use strict';
+
+const EventEmitter = require('events').EventEmitter;
+const Timers = require('timers');
+
+class Command extends EventEmitter {
+  constructor() {
+    super();
+    this.next = null;
+  }
+
+  // slow. debug only
+  stateName() {
+    const state = this.next;
+    for (const i in this) {
+      if (this[i] === state && i !== 'next') {
+        return i;
+      }
+    }
+    return 'unknown name';
+  }
+
+  execute(packet, connection) {
+    if (!this.next) {
+      this.next = this.start;
+      connection._resetSequenceId();
+    }
+    if (packet && packet.isError()) {
+      const err = packet.asError(connection.clientEncoding);
+      err.sql = this.sql || this.query;
+      if (this.queryTimeout) {
+        Timers.clearTimeout(this.queryTimeout);
+        this.queryTimeout = null;
+      }
+      if (this.onResult) {
+        this.onResult(err);
+        this.emit('end');
+      } else {
+        this.emit('error', err);
+        this.emit('end');
+      }
+      return true;
+    }
+    // TODO: don't return anything from execute, it's ugly and error-prone. Listen for 'end' event in connection
+    this.next = this.next(packet, connection);
+    if (this.next) {
+      return false;
+    }
+    this.emit('end');
+    return true;
+  }
+}
+
+module.exports = Command;

backend/node_modules/mysql2/lib/commands/execute.js

@@ -0,0 +1,116 @@
+'use strict';
+
+const Command = require('./command.js');
+const Query = require('./query.js');
+const Packets = require('../packets/index.js');
+
+const getBinaryParser = require('../parsers/binary_parser.js');
+const getStaticBinaryParser = require('../parsers/static_binary_parser.js');
+
+class Execute extends Command {
+  constructor(options, callback) {
+    super();
+    this.statement = options.statement;
+    this.sql = options.sql;
+    this.values = options.values;
+    this.onResult = callback;
+    this.parameters = options.values;
+    this.insertId = 0;
+    this.timeout = options.timeout;
+    this.queryTimeout = null;
+    this._rows = [];
+    this._fields = [];
+    this._result = [];
+    this._fieldCount = 0;
+    this._rowParser = null;
+    this._executeOptions = options;
+    this._resultIndex = 0;
+    this._localStream = null;
+    this._unpipeStream = function () {};
+    this._streamFactory = options.infileStreamFactory;
+    this._connection = null;
+  }
+
+  buildParserFromFields(fields, connection) {
+    if (this.options.disableEval) {
+      return getStaticBinaryParser(fields, this.options, connection.config);
+    }
+
+    return getBinaryParser(fields, this.options, connection.config);
+  }
+
+  start(packet, connection) {
+    this._connection = connection;
+    this.options = Object.assign({}, connection.config, this._executeOptions);
+    this._setTimeout();
+    const clientFlags =
+      connection.config.clientFlags & (connection.serverCapabilityFlags || 0);
+    const executePacket = new Packets.Execute(
+      this.statement.id,
+      this.parameters,
+      connection.config.charsetNumber,
+      connection.config.timezone,
+      this._executeOptions.attributes,
+      clientFlags
+    );
+    //For reasons why this try-catch is here, please see
+    // https://github.com/sidorares/node-mysql2/pull/689
+    //For additional discussion, see
+    // 1. https://github.com/sidorares/node-mysql2/issues/493
+    // 2. https://github.com/sidorares/node-mysql2/issues/187
+    // 3. https://github.com/sidorares/node-mysql2/issues/480
+    try {
+      connection.writePacket(executePacket.toPacket(1));
+    } catch (error) {
+      this.onResult(error);
+    }
+    return Execute.prototype.resultsetHeader;
+  }
+
+  readField(packet, connection) {
+    let fields;
+    // disabling for now, but would be great to find reliable way to parse fields only once
+    // fields reported by prepare can be empty at all or just incorrect - see #169
+    //
+    // perfomance optimisation: if we already have this field parsed in statement header, use one from header
+    // const field = this.statement.columns.length == this._fieldCount ?
+    //  this.statement.columns[this._receivedFieldsCount] : new Packets.ColumnDefinition(packet);
+    const field = new Packets.ColumnDefinition(
+      packet,
+      connection.clientEncoding
+    );
+    this._receivedFieldsCount++;
+    this._fields[this._resultIndex].push(field);
+    if (this._receivedFieldsCount === this._fieldCount) {
+      fields = this._fields[this._resultIndex];
+      this.emit('fields', fields, this._resultIndex);
+      return Execute.prototype.fieldsEOF;
+    }
+    return Execute.prototype.readField;
+  }
+
+  fieldsEOF(packet, connection) {
+    // check EOF
+    if (!packet.isEOF()) {
+      return connection.protocolError('Expected EOF packet');
+    }
+    this._rowParser = new (this.buildParserFromFields(
+      this._fields[this._resultIndex],
+      connection
+    ))();
+    return Execute.prototype.row;
+  }
+}
+
+Execute.prototype.done = Query.prototype.done;
+Execute.prototype.doneInsert = Query.prototype.doneInsert;
+Execute.prototype.resultsetHeader = Query.prototype.resultsetHeader;
+Execute.prototype._findOrCreateReadStream =
+  Query.prototype._findOrCreateReadStream;
+Execute.prototype._streamLocalInfile = Query.prototype._streamLocalInfile;
+Execute.prototype._setTimeout = Query.prototype._setTimeout;
+Execute.prototype._handleTimeoutError = Query.prototype._handleTimeoutError;
+Execute.prototype.row = Query.prototype.row;
+Execute.prototype.stream = Query.prototype.stream;
+
+module.exports = Execute;

backend/node_modules/mysql2/lib/commands/index.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const ClientHandshake = require('./client_handshake.js');
+const ServerHandshake = require('./server_handshake.js');
+const Query = require('./query.js');
+const Prepare = require('./prepare.js');
+const CloseStatement = require('./close_statement.js');
+const Execute = require('./execute.js');
+const Ping = require('./ping.js');
+const RegisterSlave = require('./register_slave.js');
+const BinlogDump = require('./binlog_dump.js');
+const ChangeUser = require('./change_user.js');
+const ResetConnection = require('./reset_connection.js');
+const Quit = require('./quit.js');
+
+module.exports = {
+  ClientHandshake,
+  ServerHandshake,
+  Query,
+  Prepare,
+  CloseStatement,
+  Execute,
+  Ping,
+  RegisterSlave,
+  BinlogDump,
+  ChangeUser,
+  ResetConnection,
+  Quit,
+};

backend/node_modules/mysql2/lib/commands/ping.js

@@ -0,0 +1,36 @@
+'use strict';
+
+const Command = require('./command');
+const CommandCode = require('../constants/commands');
+const Packet = require('../packets/packet');
+
+// TODO: time statistics?
+// usefull for queue size and network latency monitoring
+// store created,sent,reply timestamps
+class Ping extends Command {
+  constructor(callback) {
+    super();
+    this.onResult = callback;
+  }
+
+  start(packet, connection) {
+    const ping = new Packet(
+      0,
+      Buffer.from([1, 0, 0, 0, CommandCode.PING]),
+      0,
+      5
+    );
+    connection.writePacket(ping);
+    return Ping.prototype.pingResponse;
+  }
+
+  pingResponse() {
+    // TODO: check it's OK packet. error check already done in caller
+    if (this.onResult) {
+      process.nextTick(this.onResult.bind(this));
+    }
+    return null;
+  }
+}
+
+module.exports = Ping;

backend/node_modules/mysql2/lib/commands/prepare.js

@@ -0,0 +1,143 @@
+'use strict';
+
+const Packets = require('../packets/index.js');
+const Command = require('./command.js');
+const CloseStatement = require('./close_statement.js');
+const Execute = require('./execute.js');
+
+class PreparedStatementInfo {
+  constructor(query, id, columns, parameters, connection) {
+    this.query = query;
+    this.id = id;
+    this.columns = columns;
+    this.parameters = parameters;
+    this.rowParser = null;
+    this._connection = connection;
+  }
+
+  close() {
+    return this._connection.addCommand(new CloseStatement(this.id));
+  }
+
+  execute(parameters, callback) {
+    if (typeof parameters === 'function') {
+      callback = parameters;
+      parameters = [];
+    }
+    return this._connection.addCommand(
+      new Execute({ statement: this, values: parameters }, callback)
+    );
+  }
+}
+
+class Prepare extends Command {
+  constructor(options, callback) {
+    super();
+    this.query = options.sql;
+    this.onResult = callback;
+    this.id = 0;
+    this.fieldCount = 0;
+    this.parameterCount = 0;
+    this.fields = [];
+    this.parameterDefinitions = [];
+    this.options = options;
+  }
+
+  start(packet, connection) {
+    const Connection = connection.constructor;
+    this.key = Connection.statementKey(this.options);
+    const statement = connection._statements.get(this.key);
+    if (statement) {
+      if (this.onResult) {
+        this.onResult(null, statement);
+      }
+      return null;
+    }
+    const cmdPacket = new Packets.PrepareStatement(
+      this.query,
+      connection.config.charsetNumber,
+      this.options.values
+    );
+    connection.writePacket(cmdPacket.toPacket(1));
+    return Prepare.prototype.prepareHeader;
+  }
+
+  prepareHeader(packet, connection) {
+    const header = new Packets.PreparedStatementHeader(packet);
+    this.id = header.id;
+    this.fieldCount = header.fieldCount;
+    this.parameterCount = header.parameterCount;
+    if (this.parameterCount > 0) {
+      return Prepare.prototype.readParameter;
+    }
+    if (this.fieldCount > 0) {
+      return Prepare.prototype.readField;
+    }
+    return this.prepareDone(connection);
+  }
+
+  readParameter(packet, connection) {
+    // there might be scenarios when mysql server reports more parameters than
+    // are actually present in the array of parameter definitions.
+    // if EOF packet is received we switch to "read fields" state if there are
+    // any fields reported by the server, otherwise we finish the command.
+    if (packet.isEOF()) {
+      if (this.fieldCount > 0) {
+        return Prepare.prototype.readField;
+      }
+      return this.prepareDone(connection);
+    }
+    const def = new Packets.ColumnDefinition(packet, connection.clientEncoding);
+    this.parameterDefinitions.push(def);
+    if (this.parameterDefinitions.length === this.parameterCount) {
+      return Prepare.prototype.parametersEOF;
+    }
+    return this.readParameter;
+  }
+
+  readField(packet, connection) {
+    if (packet.isEOF()) {
+      return this.prepareDone(connection);
+    }
+    const def = new Packets.ColumnDefinition(packet, connection.clientEncoding);
+    this.fields.push(def);
+    if (this.fields.length === this.fieldCount) {
+      return Prepare.prototype.fieldsEOF;
+    }
+    return Prepare.prototype.readField;
+  }
+
+  parametersEOF(packet, connection) {
+    if (!packet.isEOF()) {
+      return connection.protocolError('Expected EOF packet after parameters');
+    }
+    if (this.fieldCount > 0) {
+      return Prepare.prototype.readField;
+    }
+    return this.prepareDone(connection);
+  }
+
+  fieldsEOF(packet, connection) {
+    if (!packet.isEOF()) {
+      return connection.protocolError('Expected EOF packet after fields');
+    }
+    return this.prepareDone(connection);
+  }
+
+  prepareDone(connection) {
+    const statement = new PreparedStatementInfo(
+      this.query,
+      this.id,
+      this.fields,
+      this.parameterDefinitions,
+      connection
+    );
+    connection._statements.set(this.key, statement);
+    if (this.onResult) {
+      this.onResult(null, statement);
+    }
+    return null;
+  }
+}
+
+module.exports = Prepare;

backend/node_modules/mysql2/lib/commands/query.js

@@ -0,0 +1,365 @@
+'use strict';
+
+const process = require('process');
+const Timers = require('timers');
+
+const Readable = require('stream').Readable;
+
+const Command = require('./command.js');
+const Packets = require('../packets/index.js');
+const getTextParser = require('../parsers/text_parser.js');
+const staticParser = require('../parsers/static_text_parser.js');
+const ServerStatus = require('../constants/server_status.js');
+
+const EmptyPacket = new Packets.Packet(0, Buffer.allocUnsafe(4), 0, 4);
+
+// http://dev.mysql.com/doc/internals/en/com-query.html
+class Query extends Command {
+  constructor(options, callback) {
+    super();
+    this.sql = options.sql;
+    this.values = options.values;
+    this._queryOptions = options;
+    this.namedPlaceholders = options.namedPlaceholders || false;
+    this.onResult = callback;
+    this.timeout = options.timeout;
+    this.queryTimeout = null;
+    this._fieldCount = 0;
+    this._rowParser = null;
+    this._fields = [];
+    this._rows = [];
+    this._receivedFieldsCount = 0;
+    this._resultIndex = 0;
+    this._localStream = null;
+    this._unpipeStream = function () {};
+    this._streamFactory = options.infileStreamFactory;
+    this._connection = null;
+  }
+
+  then() {
+    const err =
+      "You have tried to call .then(), .catch(), or invoked await on the result of query that is not a promise, which is a programming error. Try calling con.promise().query(), or require('mysql2/promise') instead of 'mysql2' for a promise-compatible version of the query interface. To learn how to use async/await or Promises check out documentation at https://sidorares.github.io/node-mysql2/docs#using-promise-wrapper, or the mysql2 documentation at https://sidorares.github.io/node-mysql2/docs/documentation/promise-wrapper";
+
+    console.log(err);
+    throw new Error(err);
+  }
+
+  /* eslint no-unused-vars: ["error", { "argsIgnorePattern": "^_" }] */
+  start(_packet, connection) {
+    if (connection.config.debug) {
+      console.log('        Sending query command: %s', this.sql);
+    }
+    this._connection = connection;
+    this.options = Object.assign({}, connection.config, this._queryOptions);
+    this._setTimeout();
+
+    const clientFlags =
+      connection.config.clientFlags & (connection.serverCapabilityFlags || 0);
+    const cmdPacket = new Packets.Query(
+      this.sql,
+      connection.config.charsetNumber,
+      this._queryOptions.attributes,
+      clientFlags
+    );
+    connection.writePacket(cmdPacket.toPacket(1));
+    return Query.prototype.resultsetHeader;
+  }
+
+  done() {
+    this._unpipeStream();
+    // if all ready timeout, return null directly
+    if (this.timeout && !this.queryTimeout) {
+      return null;
+    }
+    // else clear timer
+    if (this.queryTimeout) {
+      Timers.clearTimeout(this.queryTimeout);
+      this.queryTimeout = null;
+    }
+    if (this.onResult) {
+      let rows, fields;
+      if (this._resultIndex === 0) {
+        rows = this._rows[0];
+        fields = this._fields[0];
+      } else {
+        rows = this._rows;
+        fields = this._fields;
+      }
+      if (fields) {
+        process.nextTick(() => {
+          this.onResult(null, rows, fields);
+        });
+      } else {
+        process.nextTick(() => {
+          this.onResult(null, rows);
+        });
+      }
+    }
+    return null;
+  }
+
+  doneInsert(rs) {
+    if (this._localStreamError) {
+      if (this.onResult) {
+        this.onResult(this._localStreamError, rs);
+      } else {
+        this.emit('error', this._localStreamError);
+      }
+      return null;
+    }
+    this._rows.push(rs);
+    this._fields.push(void 0);
+    this.emit('fields', void 0);
+    this.emit('result', rs);
+    if (rs.serverStatus & ServerStatus.SERVER_MORE_RESULTS_EXISTS) {
+      this._resultIndex++;
+      return this.resultsetHeader;
+    }
+    return this.done();
+  }
+
+  resultsetHeader(packet, connection) {
+    const rs = new Packets.ResultSetHeader(packet, connection);
+    this._fieldCount = rs.fieldCount;
+    if (connection.config.debug) {
+      console.log(
+        `        Resultset header received, expecting ${rs.fieldCount} column definition packets`
+      );
+    }
+    if (this._fieldCount === 0) {
+      return this.doneInsert(rs);
+    }
+    if (this._fieldCount === null) {
+      return this._streamLocalInfile(connection, rs.infileName);
+    }
+    this._receivedFieldsCount = 0;
+    this._rows.push([]);
+    this._fields.push([]);
+    return this.readField;
+  }
+
+  _streamLocalInfile(connection, path) {
+    if (this._streamFactory) {
+      this._localStream = this._streamFactory(path);
+    } else {
+      this._localStreamError = new Error(
+        `As a result of LOCAL INFILE command server wants to read ${path} file, but as of v2.0 you must provide streamFactory option returning ReadStream.`
+      );
+      connection.writePacket(EmptyPacket);
+      return this.infileOk;
+    }
+
+    const onConnectionError = () => {
+      this._unpipeStream();
+    };
+    const onDrain = () => {
+      this._localStream.resume();
+    };
+    const onPause = () => {
+      this._localStream.pause();
+    };
+    const onData = function (data) {
+      const dataWithHeader = Buffer.allocUnsafe(data.length + 4);
+      data.copy(dataWithHeader, 4);
+      connection.writePacket(
+        new Packets.Packet(0, dataWithHeader, 0, dataWithHeader.length)
+      );
+    };
+    const onEnd = () => {
+      connection.removeListener('error', onConnectionError);
+      connection.writePacket(EmptyPacket);
+    };
+    const onError = (err) => {
+      this._localStreamError = err;
+      connection.removeListener('error', onConnectionError);
+      connection.writePacket(EmptyPacket);
+    };
+    this._unpipeStream = () => {
+      connection.stream.removeListener('pause', onPause);
+      connection.stream.removeListener('drain', onDrain);
+      this._localStream.removeListener('data', onData);
+      this._localStream.removeListener('end', onEnd);
+      this._localStream.removeListener('error', onError);
+    };
+    connection.stream.on('pause', onPause);
+    connection.stream.on('drain', onDrain);
+    this._localStream.on('data', onData);
+    this._localStream.on('end', onEnd);
+    this._localStream.on('error', onError);
+    connection.once('error', onConnectionError);
+    return this.infileOk;
+  }
+
+  readField(packet, connection) {
+    this._receivedFieldsCount++;
+    // Often there is much more data in the column definition than in the row itself
+    // If you set manually _fields[0] to array of ColumnDefinition's (from previous call)
+    // you can 'cache' result of parsing. Field packets still received, but ignored in that case
+    // this is the reason _receivedFieldsCount exist (otherwise we could just use current length of fields array)
+    if (this._fields[this._resultIndex].length !== this._fieldCount) {
+      const field = new Packets.ColumnDefinition(
+        packet,
+        connection.clientEncoding
+      );
+      this._fields[this._resultIndex].push(field);
+      if (connection.config.debug) {
+        console.log('        Column definition:');
+        console.log(`          name: ${field.name}`);
+        console.log(`          type: ${field.columnType}`);
+        console.log(`         flags: ${field.flags}`);
+      }
+    }
+    // last field received
+    if (this._receivedFieldsCount === this._fieldCount) {
+      const fields = this._fields[this._resultIndex];
+      this.emit('fields', fields);
+      if (this.options.disableEval) {
+        this._rowParser = staticParser(fields, this.options, connection.config);
+      } else {
+        this._rowParser = new (getTextParser(
+          fields,
+          this.options,
+          connection.config
+        ))(fields);
+      }
+      return Query.prototype.fieldsEOF;
+    }
+    return Query.prototype.readField;
+  }
+
+  fieldsEOF(packet, connection) {
+    // check EOF
+    if (!packet.isEOF()) {
+      return connection.protocolError('Expected EOF packet');
+    }
+    return this.row;
+  }
+
+  row(packet, _connection) {
+    if (packet.isEOF()) {
+      const status = packet.eofStatusFlags();
+      const moreResults = status & ServerStatus.SERVER_MORE_RESULTS_EXISTS;
+      if (moreResults) {
+        this._resultIndex++;
+        return Query.prototype.resultsetHeader;
+      }
+      return this.done();
+    }
+    let row;
+    try {
+      row = this._rowParser.next(
+        packet,
+        this._fields[this._resultIndex],
+        this.options
+      );
+    } catch (err) {
+      this._localStreamError = err;
+      return this.doneInsert(null);
+    }
+    if (this.onResult) {
+      this._rows[this._resultIndex].push(row);
+    } else {
+      this.emit('result', row, this._resultIndex);
+    }
+    return Query.prototype.row;
+  }
+
+  infileOk(packet, connection) {
+    const rs = new Packets.ResultSetHeader(packet, connection);
+    return this.doneInsert(rs);
+  }
+
+  stream(options) {
+    options = options || Object.create(null);
+    options.objectMode = true;
+
+    const stream = new Readable({
+      ...options,
+      emitClose: true,
+      autoDestroy: true,
+      read: () => {
+        this._connection && this._connection.resume();
+      },
+    });
+
+    // Prevent a breaking change for users that rely on `end` event
+    stream.once('close', () => {
+      if (!stream.readableEnded) {
+        stream.emit('end');
+      }
+    });
+
+    const onResult = (row, index) => {
+      if (stream.destroyed) return;
+
+      if (!stream.push(row)) {
+        this._connection && this._connection.pause();
+      }
+
+      stream.emit('result', row, index); // replicate old emitter
+    };
+
+    const onFields = (fields) => {
+      if (stream.destroyed) return;
+
+      stream.emit('fields', fields); // replicate old emitter
+    };
+
+    const onEnd = () => {
+      if (stream.destroyed) return;
+
+      stream.push(null); // pushing null, indicating EOF
+    };
+
+    const onError = (err) => {
+      stream.destroy(err);
+    };
+
+    stream._destroy = (err, cb) => {
+      this._connection && this._connection.resume();
+
+      this.removeListener('result', onResult);
+      this.removeListener('fields', onFields);
+      this.removeListener('end', onEnd);
+      this.removeListener('error', onError);
+
+      cb(err); // Pass on any errors
+    };
+
+    this.on('result', onResult);
+    this.on('fields', onFields);
+    this.on('end', onEnd);
+    this.on('error', onError);
+
+    return stream;
+  }
+
+  _setTimeout() {
+    if (this.timeout) {
+      const timeoutHandler = this._handleTimeoutError.bind(this);
+      this.queryTimeout = Timers.setTimeout(timeoutHandler, this.timeout);
+    }
+  }
+
+  _handleTimeoutError() {
+    if (this.queryTimeout) {
+      Timers.clearTimeout(this.queryTimeout);
+      this.queryTimeout = null;
+    }
+
+    const err = new Error('Query inactivity timeout');
+    err.errorno = 'PROTOCOL_SEQUENCE_TIMEOUT';
+    err.code = 'PROTOCOL_SEQUENCE_TIMEOUT';
+    err.syscall = 'query';
+
+    if (this.onResult) {
+      this.onResult(err);
+    } else {
+      this.emit('error', err);
+    }
+  }
+}
+
+Query.prototype.catch = Query.prototype.then;
+
+module.exports = Query;

backend/node_modules/mysql2/lib/commands/quit.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const Command = require('./command.js');
+const CommandCode = require('../constants/commands.js');
+const Packet = require('../packets/packet.js');
+
+class Quit extends Command {
+  constructor(callback) {
+    super();
+    this.onResult = callback;
+  }
+
+  start(packet, connection) {
+    connection._closing = true;
+    const quit = new Packet(
+      0,
+      Buffer.from([1, 0, 0, 0, CommandCode.QUIT]),
+      0,
+      5
+    );
+    if (this.onResult) {
+      this.onResult();
+    }
+    connection.writePacket(quit);
+    return null;
+  }
+}
+
+module.exports = Quit;

backend/node_modules/mysql2/lib/commands/register_slave.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const Command = require('./command');
+const Packets = require('../packets');
+
+class RegisterSlave extends Command {
+  constructor(opts, callback) {
+    super();
+    this.onResult = callback;
+    this.opts = opts;
+  }
+
+  start(packet, connection) {
+    const newPacket = new Packets.RegisterSlave(this.opts);
+    connection.writePacket(newPacket.toPacket(1));
+    return RegisterSlave.prototype.registerResponse;
+  }
+
+  registerResponse() {
+    if (this.onResult) {
+      process.nextTick(this.onResult.bind(this));
+    }
+    return null;
+  }
+}
+
+module.exports = RegisterSlave;

backend/node_modules/mysql2/lib/commands/reset_connection.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const Command = require('./command');
+const Packets = require('../packets/index.js');
+
+class ResetConnection extends Command {
+  constructor(callback) {
+    super();
+    this.onResult = callback;
+  }
+
+  start(packet, connection) {
+    const req = new Packets.ResetConnection();
+    connection.writePacket(req.toPacket());
+    return ResetConnection.prototype.resetConnectionResponse;
+  }
+
+  resetConnectionResponse(packet, connection) {
+    if (connection._statements) {
+      connection._statements.clear();
+    }
+    if (this.onResult) {
+      process.nextTick(this.onResult.bind(this, null));
+    }
+    return null;
+  }
+}
+
+module.exports = ResetConnection;

backend/node_modules/mysql2/lib/commands/server_handshake.js

@@ -0,0 +1,205 @@
+'use strict';
+
+const CommandCode = require('../constants/commands.js');
+const Errors = require('../constants/errors.js');
+
+const Command = require('./command.js');
+const Packets = require('../packets/index.js');
+
+class ServerHandshake extends Command {
+  constructor(args) {
+    super();
+    this.args = args;
+    /*
+    this.protocolVersion = args.protocolVersion || 10;
+    this.serverVersion   = args.serverVersion;
+    this.connectionId    = args.connectionId,
+    this.statusFlags     = args.statusFlags,
+    this.characterSet    = args.characterSet,
+    this.capabilityFlags = args.capabilityFlags || 512;
+    */
+  }
+
+  start(packet, connection) {
+    const serverHelloPacket = new Packets.Handshake(this.args);
+    this.serverHello = serverHelloPacket;
+    serverHelloPacket.setScrambleData((err) => {
+      if (err) {
+        connection.emit('error', new Error('Error generating random bytes'));
+        return;
+      }
+      connection.writePacket(serverHelloPacket.toPacket(0));
+    });
+    return ServerHandshake.prototype.readClientReply;
+  }
+
+  readClientReply(packet, connection) {
+    // check auth here
+    const clientHelloReply = Packets.HandshakeResponse.fromPacket(
+      packet,
+      this.args.capabilityFlags
+    );
+    // TODO check we don't have something similar already
+    connection.clientHelloReply = clientHelloReply;
+    if (this.args.authCallback) {
+      this.args.authCallback(
+        {
+          user: clientHelloReply.user,
+          database: clientHelloReply.database,
+          address: connection.stream.remoteAddress,
+          authPluginData1: this.serverHello.authPluginData1,
+          authPluginData2: this.serverHello.authPluginData2,
+          authToken: clientHelloReply.authToken,
+        },
+        (err, mysqlError) => {
+          // if (err)
+          if (!mysqlError) {
+            connection.writeOk();
+          } else {
+            // TODO create constants / errorToCode
+            // 1045 = ER_ACCESS_DENIED_ERROR
+            connection.writeError({
+              message: mysqlError.message || '',
+              code: mysqlError.code || 1045,
+            });
+            connection.close();
+          }
+        }
+      );
+    } else {
+      connection.writeOk();
+    }
+    return ServerHandshake.prototype.dispatchCommands;
+  }
+
+  _isStatement(query, name) {
+    const firstWord = query.split(' ')[0].toUpperCase();
+    return firstWord === name;
+  }
+
+  dispatchCommands(packet, connection) {
+    // command from client to server
+    let knownCommand = true;
+    const encoding = connection.clientHelloReply.encoding;
+    const commandCode = packet.readInt8();
+    switch (commandCode) {
+      case CommandCode.STMT_PREPARE:
+        if (connection.listeners('stmt_prepare').length) {
+          const query = packet.readString(undefined, encoding);
+          connection.emit('stmt_prepare', query);
+        } else {
+          connection.writeError({
+            code: Errors.HA_ERR_INTERNAL_ERROR,
+            message: 'No query handler for prepared statements.',
+          });
+        }
+        break;
+      case CommandCode.STMT_EXECUTE:
+        if (connection.listeners('stmt_execute').length) {
+          const { stmtId, flags, iterationCount, values } =
+            Packets.Execute.fromPacket(packet, encoding);
+          connection.emit(
+            'stmt_execute',
+            stmtId,
+            flags,
+            iterationCount,
+            values
+          );
+        } else {
+          connection.writeError({
+            code: Errors.HA_ERR_INTERNAL_ERROR,
+            message: 'No query handler for execute statements.',
+          });
+        }
+        break;
+      case CommandCode.QUIT:
+        if (connection.listeners('quit').length) {
+          connection.emit('quit');
+        } else {
+          connection.stream.end();
+        }
+        break;
+      case CommandCode.INIT_DB:
+        if (connection.listeners('init_db').length) {
+          const schemaName = packet.readString(undefined, encoding);
+          connection.emit('init_db', schemaName);
+        } else {
+          connection.writeOk();
+        }
+        break;
+      case CommandCode.QUERY:
+        if (connection.listeners('query').length) {
+          const query = packet.readString(undefined, encoding);
+          if (
+            this._isStatement(query, 'PREPARE') ||
+            this._isStatement(query, 'SET')
+          ) {
+            connection.emit('stmt_prepare', query);
+          } else if (this._isStatement(query, 'EXECUTE')) {
+            connection.emit('stmt_execute', null, null, null, null, query);
+          } else connection.emit('query', query);
+        } else {
+          connection.writeError({
+            code: Errors.HA_ERR_INTERNAL_ERROR,
+            message: 'No query handler',
+          });
+        }
+        break;
+      case CommandCode.FIELD_LIST:
+        if (connection.listeners('field_list').length) {
+          const table = packet.readNullTerminatedString(encoding);
+          const fields = packet.readString(undefined, encoding);
+          connection.emit('field_list', table, fields);
+        } else {
+          connection.writeError({
+            code: Errors.ER_WARN_DEPRECATED_SYNTAX,
+            message:
+              'As of MySQL 5.7.11, COM_FIELD_LIST is deprecated and will be removed in a future version of MySQL.',
+          });
+        }
+        break;
+      case CommandCode.PING:
+        if (connection.listeners('ping').length) {
+          connection.emit('ping');
+        } else {
+          connection.writeOk();
+        }
+        break;
+      default:
+        knownCommand = false;
+    }
+    if (connection.listeners('packet').length) {
+      connection.emit('packet', packet.clone(), knownCommand, commandCode);
+    } else if (!knownCommand) {
+      console.log('Unknown command:', commandCode);
+    }
+    return ServerHandshake.prototype.dispatchCommands;
+  }
+}
+
+module.exports = ServerHandshake;
+
+// TODO: implement server-side 4.1 authentication
+/*
+4.1 authentication: (http://bazaar.launchpad.net/~mysql/mysql-server/5.5/view/head:/sql/password.c)
+
+  SERVER:  public_seed=create_random_string()
+           send(public_seed)
+
+  CLIENT:  recv(public_seed)
+           hash_stage1=sha1("password")
+           hash_stage2=sha1(hash_stage1)
+           reply=xor(hash_stage1, sha1(public_seed,hash_stage2)
+
+           // this three steps are done in scramble()
+
+           send(reply)
+
+
+  SERVER:  recv(reply)
+           hash_stage1=xor(reply, sha1(public_seed,hash_stage2))
+           candidate_hash2=sha1(hash_stage1)
+           check(candidate_hash2==hash_stage2)
+
+server stores sha1(sha1(password)) ( hash_stag2)
+*/

backend/node_modules/mysql2/lib/compressed_protocol.js

@@ -0,0 +1,153 @@
+'use strict';
+
+// connection mixins
+// implementation of http://dev.mysql.com/doc/internals/en/compression.html
+
+const zlib = require('zlib');
+const PacketParser = require('./packet_parser.js');
+
+class Queue {
+  constructor() {
+    this._queue = [];
+    this._running = false;
+  }
+
+  push(fn) {
+    this._queue.push(fn);
+    if (!this._running) {
+      this._running = true;
+      process.nextTick(() => this._next());
+    }
+  }
+
+  _next() {
+    const task = this._queue.shift();
+    if (!task) {
+      this._running = false;
+      return;
+    }
+    task({
+      done: () => process.nextTick(() => this._next()),
+    });
+  }
+}
+
+function handleCompressedPacket(packet) {
+  // eslint-disable-next-line consistent-this, no-invalid-this
+  const connection = this;
+  const deflatedLength = packet.readInt24();
+  const body = packet.readBuffer();
+
+  if (deflatedLength !== 0) {
+    connection.inflateQueue.push((task) => {
+      zlib.inflate(body, (err, data) => {
+        if (err) {
+          connection._handleNetworkError(err);
+          return;
+        }
+        connection._bumpCompressedSequenceId(packet.numPackets);
+        connection._inflatedPacketsParser.execute(data);
+        task.done();
+      });
+    });
+  } else {
+    connection.inflateQueue.push((task) => {
+      connection._bumpCompressedSequenceId(packet.numPackets);
+      connection._inflatedPacketsParser.execute(body);
+      task.done();
+    });
+  }
+}
+
+function writeCompressed(buffer) {
+  // http://dev.mysql.com/doc/internals/en/example-several-mysql-packets.html
+  // note: sending a MySQL Packet of the size 2^24−5 to 2^24−1 via compression
+  // leads to at least one extra compressed packet.
+  // (this is because "length of the packet before compression" need to fit
+  // into 3 byte unsigned int. "length of the packet before compression" includes
+  // 4 byte packet header, hence 2^24−5)
+  const MAX_COMPRESSED_LENGTH = 16777210;
+  let start;
+  if (buffer.length > MAX_COMPRESSED_LENGTH) {
+    for (start = 0; start < buffer.length; start += MAX_COMPRESSED_LENGTH) {
+      writeCompressed.call(
+        // eslint-disable-next-line no-invalid-this
+        this,
+        buffer.slice(start, start + MAX_COMPRESSED_LENGTH)
+      );
+    }
+    return;
+  }
+
+  // eslint-disable-next-line no-invalid-this, consistent-this
+  const connection = this;
+
+  let packetLen = buffer.length;
+  const compressHeader = Buffer.allocUnsafe(7);
+
+  // seqqueue is used here because zlib async execution is routed via thread pool
+  // internally and when we have multiple compressed packets arriving we need
+  // to assemble uncompressed result sequentially
+  (function (seqId) {
+    connection.deflateQueue.push((task) => {
+      zlib.deflate(buffer, (err, compressed) => {
+        if (err) {
+          connection._handleFatalError(err);
+          return;
+        }
+        let compressedLength = compressed.length;
+
+        if (compressedLength < packetLen) {
+          compressHeader.writeUInt8(compressedLength & 0xff, 0);
+          compressHeader.writeUInt16LE(compressedLength >> 8, 1);
+          compressHeader.writeUInt8(seqId, 3);
+          compressHeader.writeUInt8(packetLen & 0xff, 4);
+          compressHeader.writeUInt16LE(packetLen >> 8, 5);
+          connection.writeUncompressed(compressHeader);
+          connection.writeUncompressed(compressed);
+        } else {
+          // http://dev.mysql.com/doc/internals/en/uncompressed-payload.html
+          // To send an uncompressed payload:
+          //   - set length of payload before compression to 0
+          //   - the compressed payload contains the uncompressed payload instead.
+          compressedLength = packetLen;
+          packetLen = 0;
+          compressHeader.writeUInt8(compressedLength & 0xff, 0);
+          compressHeader.writeUInt16LE(compressedLength >> 8, 1);
+          compressHeader.writeUInt8(seqId, 3);
+          compressHeader.writeUInt8(packetLen & 0xff, 4);
+          compressHeader.writeUInt16LE(packetLen >> 8, 5);
+          connection.writeUncompressed(compressHeader);
+          connection.writeUncompressed(buffer);
+        }
+        task.done();
+      });
+    });
+  })(connection.compressedSequenceId);
+  connection._bumpCompressedSequenceId(1);
+}
+
+function enableCompression(connection) {
+  connection._lastWrittenPacketId = 0;
+  connection._lastReceivedPacketId = 0;
+
+  connection._handleCompressedPacket = handleCompressedPacket;
+  connection._inflatedPacketsParser = new PacketParser((p) => {
+    connection.handlePacket(p);
+  }, 4);
+  connection._inflatedPacketsParser._lastPacket = 0;
+  connection.packetParser = new PacketParser((packet) => {
+    connection._handleCompressedPacket(packet);
+  }, 7);
+
+  connection.writeUncompressed = connection.write;
+  connection.write = writeCompressed;
+
+  connection.inflateQueue = new Queue();
+  connection.deflateQueue = new Queue();
+}
+
+module.exports = {
+  enableCompression: enableCompression,
+  Queue: Queue,
+};

backend/node_modules/mysql2/lib/connection.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const BaseConnection = require('./base/connection.js');
+
+class Connection extends BaseConnection {
+  promise(promiseImpl) {
+    const PromiseConnection = require('./promise/connection.js');
+    return new PromiseConnection(this, promiseImpl);
+  }
+}
+
+module.exports = Connection;

backend/node_modules/mysql2/lib/connection_config.js

@@ -0,0 +1,300 @@
+// This file was modified by Oracle on September 21, 2021.
+// New connection options for additional authentication factors were
+// introduced.
+// Multi-factor authentication capability is now enabled if one of these
+// options is used.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+const { URL } = require('url');
+const ClientConstants = require('./constants/client');
+const Charsets = require('./constants/charsets');
+const { version } = require('../package.json');
+let SSLProfiles = null;
+
+const validOptions = {
+  authPlugins: 1,
+  authSwitchHandler: 1,
+  bigNumberStrings: 1,
+  charset: 1,
+  charsetNumber: 1,
+  compress: 1,
+  connectAttributes: 1,
+  connectTimeout: 1,
+  database: 1,
+  dateStrings: 1,
+  debug: 1,
+  decimalNumbers: 1,
+  enableKeepAlive: 1,
+  flags: 1,
+  host: 1,
+  insecureAuth: 1,
+  infileStreamFactory: 1,
+  isServer: 1,
+  keepAliveInitialDelay: 1,
+  localAddress: 1,
+  maxPreparedStatements: 1,
+  multipleStatements: 1,
+  namedPlaceholders: 1,
+  nestTables: 1,
+  password: 1,
+  // with multi-factor authentication, the main password (used for the first
+  // authentication factor) can be provided via password1
+  password1: 1,
+  password2: 1,
+  password3: 1,
+  passwordSha1: 1,
+  pool: 1,
+  port: 1,
+  queryFormat: 1,
+  rowsAsArray: 1,
+  socketPath: 1,
+  ssl: 1,
+  stream: 1,
+  stringifyObjects: 1,
+  supportBigNumbers: 1,
+  timezone: 1,
+  trace: 1,
+  typeCast: 1,
+  uri: 1,
+  user: 1,
+  disableEval: 1,
+  enableCleartextPlugin: 1,
+  // These options are used for Pool
+  connectionLimit: 1,
+  maxIdle: 1,
+  idleTimeout: 1,
+  Promise: 1,
+  queueLimit: 1,
+  resetOnRelease: 1,
+  waitForConnections: 1,
+  jsonStrings: 1,
+  gracefulEnd: 1,
+};
+
+class ConnectionConfig {
+  constructor(options) {
+    if (typeof options === 'string') {
+      options = ConnectionConfig.parseUrl(options);
+    } else if (options && options.uri) {
+      const uriOptions = ConnectionConfig.parseUrl(options.uri);
+      for (const key in uriOptions) {
+        if (!Object.prototype.hasOwnProperty.call(uriOptions, key)) continue;
+        if (options[key]) continue;
+        options[key] = uriOptions[key];
+      }
+    }
+    for (const key in options) {
+      if (!Object.prototype.hasOwnProperty.call(options, key)) continue;
+      if (validOptions[key] !== 1) {
+        // REVIEW: Should this be emitted somehow?
+        console.error(
+          `Ignoring invalid configuration option passed to Connection: ${key}. This is currently a warning, but in future versions of MySQL2, an error will be thrown if you pass an invalid configuration option to a Connection`
+        );
+      }
+    }
+    this.isServer = options.isServer;
+    this.stream = options.stream;
+    this.host = options.host || 'localhost';
+    this.port =
+      (typeof options.port === 'string'
+        ? parseInt(options.port, 10)
+        : options.port) || 3306;
+    this.localAddress = options.localAddress;
+    this.socketPath = options.socketPath;
+    this.user = options.user || undefined;
+    // for the purpose of multi-factor authentication, or not, the main
+    // password (used for the 1st authentication factor) can also be
+    // provided via the "password1" option
+    this.password = options.password || options.password1 || undefined;
+    this.password2 = options.password2 || undefined;
+    this.password3 = options.password3 || undefined;
+    this.passwordSha1 = options.passwordSha1 || undefined;
+    this.database = options.database;
+    this.connectTimeout = isNaN(options.connectTimeout)
+      ? 10 * 1000
+      : options.connectTimeout;
+    this.insecureAuth = options.insecureAuth || false;
+    this.infileStreamFactory = options.infileStreamFactory || undefined;
+    this.supportBigNumbers = options.supportBigNumbers || false;
+    this.bigNumberStrings = options.bigNumberStrings || false;
+    this.decimalNumbers = options.decimalNumbers || false;
+    this.dateStrings = options.dateStrings || false;
+    this.debug = options.debug;
+    this.trace = options.trace !== false;
+    this.stringifyObjects = options.stringifyObjects || false;
+    this.enableKeepAlive = options.enableKeepAlive !== false;
+    this.keepAliveInitialDelay = options.keepAliveInitialDelay;
+    if (
+      options.timezone &&
+      !/^(?:local|Z|[ +-]\d\d:\d\d)$/.test(options.timezone)
+    ) {
+      // strictly supports timezones specified by mysqljs/mysql:
+      // https://github.com/mysqljs/mysql#user-content-connection-options
+
+      console.error(
+        `Ignoring invalid timezone passed to Connection: ${options.timezone}. This is currently a warning, but in future versions of MySQL2, an error will be thrown if you pass an invalid configuration option to a Connection`
+      );
+      // SqlStrings falls back to UTC on invalid timezone
+      this.timezone = 'Z';
+    } else {
+      this.timezone = options.timezone || 'local';
+    }
+    this.queryFormat = options.queryFormat;
+    this.pool = options.pool || undefined;
+    this.ssl =
+      typeof options.ssl === 'string'
+        ? ConnectionConfig.getSSLProfile(options.ssl)
+        : options.ssl || false;
+    this.multipleStatements = options.multipleStatements || false;
+    this.rowsAsArray = options.rowsAsArray || false;
+    this.namedPlaceholders = options.namedPlaceholders || false;
+    this.nestTables =
+      options.nestTables === undefined ? undefined : options.nestTables;
+    this.typeCast = options.typeCast === undefined ? true : options.typeCast;
+    this.disableEval = Boolean(options.disableEval);
+    this.enableCleartextPlugin = Boolean(options.enableCleartextPlugin);
+    if (this.timezone[0] === ' ') {
+      // "+" is a url encoded char for space so it
+      // gets translated to space when giving a
+      // connection string..
+      this.timezone = `+${this.timezone.slice(1)}`;
+    }
+    if (this.ssl) {
+      if (typeof this.ssl !== 'object') {
+        throw new TypeError(
+          `SSL profile must be an object, instead it's a ${typeof this.ssl}`
+        );
+      }
+      // Default rejectUnauthorized to true
+      this.ssl.rejectUnauthorized = this.ssl.rejectUnauthorized !== false;
+    }
+    this.maxPacketSize = 0;
+    this.charsetNumber = options.charset
+      ? ConnectionConfig.getCharsetNumber(options.charset)
+      : options.charsetNumber || Charsets.UTF8MB4_UNICODE_CI;
+    this.compress = options.compress || false;
+    this.authPlugins = options.authPlugins;
+    this.authSwitchHandler = options.authSwitchHandler;
+    this.clientFlags = ConnectionConfig.mergeFlags(
+      ConnectionConfig.getDefaultFlags(options),
+      options.flags || ''
+    );
+    // Default connection attributes
+    // https://dev.mysql.com/doc/refman/8.0/en/performance-schema-connection-attribute-tables.html
+    const defaultConnectAttributes = {
+      _client_name: 'Node-MySQL-2',
+      _client_version: version,
+    };
+    this.connectAttributes = {
+      ...defaultConnectAttributes,
+      ...(options.connectAttributes || {}),
+    };
+    this.maxPreparedStatements = options.maxPreparedStatements || 16000;
+    this.jsonStrings = options.jsonStrings || false;
+    this.gracefulEnd = options.gracefulEnd || false;
+  }
+
+  static mergeFlags(default_flags, user_flags) {
+    let flags = 0x0,
+      i;
+    if (!Array.isArray(user_flags)) {
+      user_flags = String(user_flags || '')
+        .toUpperCase()
+        .split(/\s*,+\s*/);
+    }
+    // add default flags unless "blacklisted"
+    for (i in default_flags) {
+      if (user_flags.indexOf(`-${default_flags[i]}`) >= 0) {
+        continue;
+      }
+      flags |= ClientConstants[default_flags[i]] || 0x0;
+    }
+    // add user flags unless already already added
+    for (i in user_flags) {
+      if (user_flags[i][0] === '-') {
+        continue;
+      }
+      if (default_flags.indexOf(user_flags[i]) >= 0) {
+        continue;
+      }
+      flags |= ClientConstants[user_flags[i]] || 0x0;
+    }
+    return flags;
+  }
+
+  static getDefaultFlags(options) {
+    const defaultFlags = [
+      'LONG_PASSWORD',
+      'FOUND_ROWS',
+      'LONG_FLAG',
+      'CONNECT_WITH_DB',
+      'ODBC',
+      'LOCAL_FILES',
+      'IGNORE_SPACE',
+      'PROTOCOL_41',
+      'IGNORE_SIGPIPE',
+      'TRANSACTIONS',
+      'RESERVED',
+      'SECURE_CONNECTION',
+      'MULTI_RESULTS',
+      'TRANSACTIONS',
+      'SESSION_TRACK',
+      'CONNECT_ATTRS',
+      'CLIENT_QUERY_ATTRIBUTES',
+    ];
+    if (options && options.multipleStatements) {
+      defaultFlags.push('MULTI_STATEMENTS');
+    }
+    defaultFlags.push('PLUGIN_AUTH');
+    defaultFlags.push('PLUGIN_AUTH_LENENC_CLIENT_DATA');
+
+    return defaultFlags;
+  }
+
+  static getCharsetNumber(charset) {
+    const num = Charsets[charset.toUpperCase()];
+    if (num === undefined) {
+      throw new TypeError(`Unknown charset '${charset}'`);
+    }
+    return num;
+  }
+
+  static getSSLProfile(name) {
+    if (!SSLProfiles) {
+      SSLProfiles = require('./constants/ssl_profiles.js');
+    }
+    const ssl = SSLProfiles[name];
+    if (ssl === undefined) {
+      throw new TypeError(`Unknown SSL profile '${name}'`);
+    }
+    return ssl;
+  }
+
+  static parseUrl(url) {
+    const parsedUrl = new URL(url);
+    const options = {
+      host: decodeURIComponent(parsedUrl.hostname),
+      port: parseInt(parsedUrl.port, 10),
+      database: decodeURIComponent(parsedUrl.pathname.slice(1)),
+      user: decodeURIComponent(parsedUrl.username),
+      password: decodeURIComponent(parsedUrl.password),
+    };
+    for (const [key, value] of parsedUrl.searchParams) {
+      if (key in options) {
+        continue;
+      }
+      try {
+        // Try to parse this as a JSON expression first
+        options[key] = JSON.parse(value);
+      } catch {
+        // Otherwise assume it is a plain string
+        options[key] = value;
+      }
+    }
+    return options;
+  }
+}
+
+module.exports = ConnectionConfig;

backend/node_modules/mysql2/lib/constants/charset_encodings.js

@@ -0,0 +1,317 @@
+'use strict';
+
+// see tools/generate-charset-mapping.js
+// basicalliy result of "SHOW COLLATION" query
+
+module.exports = [
+  'utf8',
+  'big5',
+  'latin2',
+  'dec8',
+  'cp850',
+  'latin1',
+  'hp8',
+  'koi8r',
+  'latin1',
+  'latin2',
+  'swe7',
+  'ascii',
+  'eucjp',
+  'sjis',
+  'cp1251',
+  'latin1',
+  'hebrew',
+  'utf8',
+  'tis620',
+  'euckr',
+  'latin7',
+  'latin2',
+  'koi8u',
+  'cp1251',
+  'gb2312',
+  'greek',
+  'cp1250',
+  'latin2',
+  'gbk',
+  'cp1257',
+  'latin5',
+  'latin1',
+  'armscii8',
+  'cesu8',
+  'cp1250',
+  'ucs2',
+  'cp866',
+  'keybcs2',
+  'macintosh',
+  'macroman',
+  'cp852',
+  'latin7',
+  'latin7',
+  'macintosh',
+  'cp1250',
+  'utf8',
+  'utf8',
+  'latin1',
+  'latin1',
+  'latin1',
+  'cp1251',
+  'cp1251',
+  'cp1251',
+  'macroman',
+  'utf16',
+  'utf16',
+  'utf16-le',
+  'cp1256',
+  'cp1257',
+  'cp1257',
+  'utf32',
+  'utf32',
+  'utf16-le',
+  'binary',
+  'armscii8',
+  'ascii',
+  'cp1250',
+  'cp1256',
+  'cp866',
+  'dec8',
+  'greek',
+  'hebrew',
+  'hp8',
+  'keybcs2',
+  'koi8r',
+  'koi8u',
+  'cesu8',
+  'latin2',
+  'latin5',
+  'latin7',
+  'cp850',
+  'cp852',
+  'swe7',
+  'cesu8',
+  'big5',
+  'euckr',
+  'gb2312',
+  'gbk',
+  'sjis',
+  'tis620',
+  'ucs2',
+  'eucjp',
+  'geostd8',
+  'geostd8',
+  'latin1',
+  'cp932',
+  'cp932',
+  'eucjpms',
+  'eucjpms',
+  'cp1250',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf16',
+  'utf8',
+  'utf8',
+  'utf8',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'ucs2',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'ucs2',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf32',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'cesu8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'cesu8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'gb18030',
+  'gb18030',
+  'gb18030',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+  'utf8',
+];

backend/node_modules/mysql2/lib/constants/charsets.js

@@ -0,0 +1,317 @@
+'use strict';
+
+exports.BIG5_CHINESE_CI = 1;
+exports.LATIN2_CZECH_CS = 2;
+exports.DEC8_SWEDISH_CI = 3;
+exports.CP850_GENERAL_CI = 4;
+exports.LATIN1_GERMAN1_CI = 5;
+exports.HP8_ENGLISH_CI = 6;
+exports.KOI8R_GENERAL_CI = 7;
+exports.LATIN1_SWEDISH_CI = 8;
+exports.LATIN2_GENERAL_CI = 9;
+exports.SWE7_SWEDISH_CI = 10;
+exports.ASCII_GENERAL_CI = 11;
+exports.UJIS_JAPANESE_CI = 12;
+exports.SJIS_JAPANESE_CI = 13;
+exports.CP1251_BULGARIAN_CI = 14;
+exports.LATIN1_DANISH_CI = 15;
+exports.HEBREW_GENERAL_CI = 16;
+exports.TIS620_THAI_CI = 18;
+exports.EUCKR_KOREAN_CI = 19;
+exports.LATIN7_ESTONIAN_CS = 20;
+exports.LATIN2_HUNGARIAN_CI = 21;
+exports.KOI8U_GENERAL_CI = 22;
+exports.CP1251_UKRAINIAN_CI = 23;
+exports.GB2312_CHINESE_CI = 24;
+exports.GREEK_GENERAL_CI = 25;
+exports.CP1250_GENERAL_CI = 26;
+exports.LATIN2_CROATIAN_CI = 27;
+exports.GBK_CHINESE_CI = 28;
+exports.CP1257_LITHUANIAN_CI = 29;
+exports.LATIN5_TURKISH_CI = 30;
+exports.LATIN1_GERMAN2_CI = 31;
+exports.ARMSCII8_GENERAL_CI = 32;
+exports.UTF8_GENERAL_CI = 33;
+exports.CP1250_CZECH_CS = 34;
+exports.UCS2_GENERAL_CI = 35;
+exports.CP866_GENERAL_CI = 36;
+exports.KEYBCS2_GENERAL_CI = 37;
+exports.MACCE_GENERAL_CI = 38;
+exports.MACROMAN_GENERAL_CI = 39;
+exports.CP852_GENERAL_CI = 40;
+exports.LATIN7_GENERAL_CI = 41;
+exports.LATIN7_GENERAL_CS = 42;
+exports.MACCE_BIN = 43;
+exports.CP1250_CROATIAN_CI = 44;
+exports.UTF8MB4_GENERAL_CI = 45;
+exports.UTF8MB4_BIN = 46;
+exports.LATIN1_BIN = 47;
+exports.LATIN1_GENERAL_CI = 48;
+exports.LATIN1_GENERAL_CS = 49;
+exports.CP1251_BIN = 50;
+exports.CP1251_GENERAL_CI = 51;
+exports.CP1251_GENERAL_CS = 52;
+exports.MACROMAN_BIN = 53;
+exports.UTF16_GENERAL_CI = 54;
+exports.UTF16_BIN = 55;
+exports.UTF16LE_GENERAL_CI = 56;
+exports.CP1256_GENERAL_CI = 57;
+exports.CP1257_BIN = 58;
+exports.CP1257_GENERAL_CI = 59;
+exports.UTF32_GENERAL_CI = 60;
+exports.UTF32_BIN = 61;
+exports.UTF16LE_BIN = 62;
+exports.BINARY = 63;
+exports.ARMSCII8_BIN = 64;
+exports.ASCII_BIN = 65;
+exports.CP1250_BIN = 66;
+exports.CP1256_BIN = 67;
+exports.CP866_BIN = 68;
+exports.DEC8_BIN = 69;
+exports.GREEK_BIN = 70;
+exports.HEBREW_BIN = 71;
+exports.HP8_BIN = 72;
+exports.KEYBCS2_BIN = 73;
+exports.KOI8R_BIN = 74;
+exports.KOI8U_BIN = 75;
+exports.UTF8_TOLOWER_CI = 76;
+exports.LATIN2_BIN = 77;
+exports.LATIN5_BIN = 78;
+exports.LATIN7_BIN = 79;
+exports.CP850_BIN = 80;
+exports.CP852_BIN = 81;
+exports.SWE7_BIN = 82;
+exports.UTF8_BIN = 83;
+exports.BIG5_BIN = 84;
+exports.EUCKR_BIN = 85;
+exports.GB2312_BIN = 86;
+exports.GBK_BIN = 87;
+exports.SJIS_BIN = 88;
+exports.TIS620_BIN = 89;
+exports.UCS2_BIN = 90;
+exports.UJIS_BIN = 91;
+exports.GEOSTD8_GENERAL_CI = 92;
+exports.GEOSTD8_BIN = 93;
+exports.LATIN1_SPANISH_CI = 94;
+exports.CP932_JAPANESE_CI = 95;
+exports.CP932_BIN = 96;
+exports.EUCJPMS_JAPANESE_CI = 97;
+exports.EUCJPMS_BIN = 98;
+exports.CP1250_POLISH_CI = 99;
+exports.UTF16_UNICODE_CI = 101;
+exports.UTF16_ICELANDIC_CI = 102;
+exports.UTF16_LATVIAN_CI = 103;
+exports.UTF16_ROMANIAN_CI = 104;
+exports.UTF16_SLOVENIAN_CI = 105;
+exports.UTF16_POLISH_CI = 106;
+exports.UTF16_ESTONIAN_CI = 107;
+exports.UTF16_SPANISH_CI = 108;
+exports.UTF16_SWEDISH_CI = 109;
+exports.UTF16_TURKISH_CI = 110;
+exports.UTF16_CZECH_CI = 111;
+exports.UTF16_DANISH_CI = 112;
+exports.UTF16_LITHUANIAN_CI = 113;
+exports.UTF16_SLOVAK_CI = 114;
+exports.UTF16_SPANISH2_CI = 115;
+exports.UTF16_ROMAN_CI = 116;
+exports.UTF16_PERSIAN_CI = 117;
+exports.UTF16_ESPERANTO_CI = 118;
+exports.UTF16_HUNGARIAN_CI = 119;
+exports.UTF16_SINHALA_CI = 120;
+exports.UTF16_GERMAN2_CI = 121;
+exports.UTF16_CROATIAN_CI = 122;
+exports.UTF16_UNICODE_520_CI = 123;
+exports.UTF16_VIETNAMESE_CI = 124;
+exports.UCS2_UNICODE_CI = 128;
+exports.UCS2_ICELANDIC_CI = 129;
+exports.UCS2_LATVIAN_CI = 130;
+exports.UCS2_ROMANIAN_CI = 131;
+exports.UCS2_SLOVENIAN_CI = 132;
+exports.UCS2_POLISH_CI = 133;
+exports.UCS2_ESTONIAN_CI = 134;
+exports.UCS2_SPANISH_CI = 135;
+exports.UCS2_SWEDISH_CI = 136;
+exports.UCS2_TURKISH_CI = 137;
+exports.UCS2_CZECH_CI = 138;
+exports.UCS2_DANISH_CI = 139;
+exports.UCS2_LITHUANIAN_CI = 140;
+exports.UCS2_SLOVAK_CI = 141;
+exports.UCS2_SPANISH2_CI = 142;
+exports.UCS2_ROMAN_CI = 143;
+exports.UCS2_PERSIAN_CI = 144;
+exports.UCS2_ESPERANTO_CI = 145;
+exports.UCS2_HUNGARIAN_CI = 146;
+exports.UCS2_SINHALA_CI = 147;
+exports.UCS2_GERMAN2_CI = 148;
+exports.UCS2_CROATIAN_CI = 149;
+exports.UCS2_UNICODE_520_CI = 150;
+exports.UCS2_VIETNAMESE_CI = 151;
+exports.UCS2_GENERAL_MYSQL500_CI = 159;
+exports.UTF32_UNICODE_CI = 160;
+exports.UTF32_ICELANDIC_CI = 161;
+exports.UTF32_LATVIAN_CI = 162;
+exports.UTF32_ROMANIAN_CI = 163;
+exports.UTF32_SLOVENIAN_CI = 164;
+exports.UTF32_POLISH_CI = 165;
+exports.UTF32_ESTONIAN_CI = 166;
+exports.UTF32_SPANISH_CI = 167;
+exports.UTF32_SWEDISH_CI = 168;
+exports.UTF32_TURKISH_CI = 169;
+exports.UTF32_CZECH_CI = 170;
+exports.UTF32_DANISH_CI = 171;
+exports.UTF32_LITHUANIAN_CI = 172;
+exports.UTF32_SLOVAK_CI = 173;
+exports.UTF32_SPANISH2_CI = 174;
+exports.UTF32_ROMAN_CI = 175;
+exports.UTF32_PERSIAN_CI = 176;
+exports.UTF32_ESPERANTO_CI = 177;
+exports.UTF32_HUNGARIAN_CI = 178;
+exports.UTF32_SINHALA_CI = 179;
+exports.UTF32_GERMAN2_CI = 180;
+exports.UTF32_CROATIAN_CI = 181;
+exports.UTF32_UNICODE_520_CI = 182;
+exports.UTF32_VIETNAMESE_CI = 183;
+exports.UTF8_UNICODE_CI = 192;
+exports.UTF8_ICELANDIC_CI = 193;
+exports.UTF8_LATVIAN_CI = 194;
+exports.UTF8_ROMANIAN_CI = 195;
+exports.UTF8_SLOVENIAN_CI = 196;
+exports.UTF8_POLISH_CI = 197;
+exports.UTF8_ESTONIAN_CI = 198;
+exports.UTF8_SPANISH_CI = 199;
+exports.UTF8_SWEDISH_CI = 200;
+exports.UTF8_TURKISH_CI = 201;
+exports.UTF8_CZECH_CI = 202;
+exports.UTF8_DANISH_CI = 203;
+exports.UTF8_LITHUANIAN_CI = 204;
+exports.UTF8_SLOVAK_CI = 205;
+exports.UTF8_SPANISH2_CI = 206;
+exports.UTF8_ROMAN_CI = 207;
+exports.UTF8_PERSIAN_CI = 208;
+exports.UTF8_ESPERANTO_CI = 209;
+exports.UTF8_HUNGARIAN_CI = 210;
+exports.UTF8_SINHALA_CI = 211;
+exports.UTF8_GERMAN2_CI = 212;
+exports.UTF8_CROATIAN_CI = 213;
+exports.UTF8_UNICODE_520_CI = 214;
+exports.UTF8_VIETNAMESE_CI = 215;
+exports.UTF8_GENERAL_MYSQL500_CI = 223;
+exports.UTF8MB4_UNICODE_CI = 224;
+exports.UTF8MB4_ICELANDIC_CI = 225;
+exports.UTF8MB4_LATVIAN_CI = 226;
+exports.UTF8MB4_ROMANIAN_CI = 227;
+exports.UTF8MB4_SLOVENIAN_CI = 228;
+exports.UTF8MB4_POLISH_CI = 229;
+exports.UTF8MB4_ESTONIAN_CI = 230;
+exports.UTF8MB4_SPANISH_CI = 231;
+exports.UTF8MB4_SWEDISH_CI = 232;
+exports.UTF8MB4_TURKISH_CI = 233;
+exports.UTF8MB4_CZECH_CI = 234;
+exports.UTF8MB4_DANISH_CI = 235;
+exports.UTF8MB4_LITHUANIAN_CI = 236;
+exports.UTF8MB4_SLOVAK_CI = 237;
+exports.UTF8MB4_SPANISH2_CI = 238;
+exports.UTF8MB4_ROMAN_CI = 239;
+exports.UTF8MB4_PERSIAN_CI = 240;
+exports.UTF8MB4_ESPERANTO_CI = 241;
+exports.UTF8MB4_HUNGARIAN_CI = 242;
+exports.UTF8MB4_SINHALA_CI = 243;
+exports.UTF8MB4_GERMAN2_CI = 244;
+exports.UTF8MB4_CROATIAN_CI = 245;
+exports.UTF8MB4_UNICODE_520_CI = 246;
+exports.UTF8MB4_VIETNAMESE_CI = 247;
+exports.GB18030_CHINESE_CI = 248;
+exports.GB18030_BIN = 249;
+exports.GB18030_UNICODE_520_CI = 250;
+exports.UTF8_GENERAL50_CI = 253; // deprecated
+exports.UTF8MB4_0900_AI_CI = 255;
+exports.UTF8MB4_DE_PB_0900_AI_CI = 256;
+exports.UTF8MB4_IS_0900_AI_CI = 257;
+exports.UTF8MB4_LV_0900_AI_CI = 258;
+exports.UTF8MB4_RO_0900_AI_CI = 259;
+exports.UTF8MB4_SL_0900_AI_CI = 260;
+exports.UTF8MB4_PL_0900_AI_CI = 261;
+exports.UTF8MB4_ET_0900_AI_CI = 262;
+exports.UTF8MB4_ES_0900_AI_CI = 263;
+exports.UTF8MB4_SV_0900_AI_CI = 264;
+exports.UTF8MB4_TR_0900_AI_CI = 265;
+exports.UTF8MB4_CS_0900_AI_CI = 266;
+exports.UTF8MB4_DA_0900_AI_CI = 267;
+exports.UTF8MB4_LT_0900_AI_CI = 268;
+exports.UTF8MB4_SK_0900_AI_CI = 269;
+exports.UTF8MB4_ES_TRAD_0900_AI_CI = 270;
+exports.UTF8MB4_LA_0900_AI_CI = 271;
+exports.UTF8MB4_EO_0900_AI_CI = 273;
+exports.UTF8MB4_HU_0900_AI_CI = 274;
+exports.UTF8MB4_HR_0900_AI_CI = 275;
+exports.UTF8MB4_VI_0900_AI_CI = 277;
+exports.UTF8MB4_0900_AS_CS = 278;
+exports.UTF8MB4_DE_PB_0900_AS_CS = 279;
+exports.UTF8MB4_IS_0900_AS_CS = 280;
+exports.UTF8MB4_LV_0900_AS_CS = 281;
+exports.UTF8MB4_RO_0900_AS_CS = 282;
+exports.UTF8MB4_SL_0900_AS_CS = 283;
+exports.UTF8MB4_PL_0900_AS_CS = 284;
+exports.UTF8MB4_ET_0900_AS_CS = 285;
+exports.UTF8MB4_ES_0900_AS_CS = 286;
+exports.UTF8MB4_SV_0900_AS_CS = 287;
+exports.UTF8MB4_TR_0900_AS_CS = 288;
+exports.UTF8MB4_CS_0900_AS_CS = 289;
+exports.UTF8MB4_DA_0900_AS_CS = 290;
+exports.UTF8MB4_LT_0900_AS_CS = 291;
+exports.UTF8MB4_SK_0900_AS_CS = 292;
+exports.UTF8MB4_ES_TRAD_0900_AS_CS = 293;
+exports.UTF8MB4_LA_0900_AS_CS = 294;
+exports.UTF8MB4_EO_0900_AS_CS = 296;
+exports.UTF8MB4_HU_0900_AS_CS = 297;
+exports.UTF8MB4_HR_0900_AS_CS = 298;
+exports.UTF8MB4_VI_0900_AS_CS = 300;
+exports.UTF8MB4_JA_0900_AS_CS = 303;
+exports.UTF8MB4_JA_0900_AS_CS_KS = 304;
+exports.UTF8MB4_0900_AS_CI = 305;
+exports.UTF8MB4_RU_0900_AI_CI = 306;
+exports.UTF8MB4_RU_0900_AS_CS = 307;
+exports.UTF8MB4_ZH_0900_AS_CS = 308;
+exports.UTF8MB4_0900_BIN = 309;
+
+// short aliases
+exports.BIG5 = exports.BIG5_CHINESE_CI;
+exports.DEC8 = exports.DEC8_SWEDISH_CI;
+exports.CP850 = exports.CP850_GENERAL_CI;
+exports.HP8 = exports.HP8_ENGLISH_CI;
+exports.KOI8R = exports.KOI8R_GENERAL_CI;
+exports.LATIN1 = exports.LATIN1_SWEDISH_CI;
+exports.LATIN2 = exports.LATIN2_GENERAL_CI;
+exports.SWE7 = exports.SWE7_SWEDISH_CI;
+exports.ASCII = exports.ASCII_GENERAL_CI;
+exports.UJIS = exports.UJIS_JAPANESE_CI;
+exports.SJIS = exports.SJIS_JAPANESE_CI;
+exports.HEBREW = exports.HEBREW_GENERAL_CI;
+exports.TIS620 = exports.TIS620_THAI_CI;
+exports.EUCKR = exports.EUCKR_KOREAN_CI;
+exports.KOI8U = exports.KOI8U_GENERAL_CI;
+exports.GB2312 = exports.GB2312_CHINESE_CI;
+exports.GREEK = exports.GREEK_GENERAL_CI;
+exports.CP1250 = exports.CP1250_GENERAL_CI;
+exports.GBK = exports.GBK_CHINESE_CI;
+exports.LATIN5 = exports.LATIN5_TURKISH_CI;
+exports.ARMSCII8 = exports.ARMSCII8_GENERAL_CI;
+exports.UTF8 = exports.UTF8_GENERAL_CI;
+exports.UCS2 = exports.UCS2_GENERAL_CI;
+exports.CP866 = exports.CP866_GENERAL_CI;
+exports.KEYBCS2 = exports.KEYBCS2_GENERAL_CI;
+exports.MACCE = exports.MACCE_GENERAL_CI;
+exports.MACROMAN = exports.MACROMAN_GENERAL_CI;
+exports.CP852 = exports.CP852_GENERAL_CI;
+exports.LATIN7 = exports.LATIN7_GENERAL_CI;
+exports.UTF8MB4 = exports.UTF8MB4_GENERAL_CI;
+exports.CP1251 = exports.CP1251_GENERAL_CI;
+exports.UTF16 = exports.UTF16_GENERAL_CI;
+exports.UTF16LE = exports.UTF16LE_GENERAL_CI;
+exports.CP1256 = exports.CP1256_GENERAL_CI;
+exports.CP1257 = exports.CP1257_GENERAL_CI;
+exports.UTF32 = exports.UTF32_GENERAL_CI;
+exports.CP932 = exports.CP932_JAPANESE_CI;
+exports.EUCJPMS = exports.EUCJPMS_JAPANESE_CI;
+exports.GB18030 = exports.GB18030_CHINESE_CI;
+exports.GEOSTD8 = exports.GEOSTD8_GENERAL_CI;

backend/node_modules/mysql2/lib/constants/client.js

@@ -0,0 +1,39 @@
+// This file was modified by Oracle on September 21, 2021.
+// New capability for multi-factor authentication based on mandatory session
+// trackers, that are signaled with an extra single-byte prefix on new
+// versions of the MySQL server.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+// Manually extracted from mysql-5.5.23/include/mysql_com.h
+exports.LONG_PASSWORD = 0x00000001; /* new more secure passwords */
+exports.FOUND_ROWS = 0x00000002; /* found instead of affected rows */
+exports.LONG_FLAG = 0x00000004; /* get all column flags */
+exports.CONNECT_WITH_DB = 0x00000008; /* one can specify db on connect */
+exports.NO_SCHEMA = 0x00000010; /* don't allow database.table.column */
+exports.COMPRESS = 0x00000020; /* can use compression protocol */
+exports.ODBC = 0x00000040; /* odbc client */
+exports.LOCAL_FILES = 0x00000080; /* can use LOAD DATA LOCAL */
+exports.IGNORE_SPACE = 0x00000100; /* ignore spaces before '' */
+exports.PROTOCOL_41 = 0x00000200; /* new 4.1 protocol */
+exports.INTERACTIVE = 0x00000400; /* this is an interactive client */
+exports.SSL = 0x00000800; /* switch to ssl after handshake */
+exports.IGNORE_SIGPIPE = 0x00001000; /* IGNORE sigpipes */
+exports.TRANSACTIONS = 0x00002000; /* client knows about transactions */
+exports.RESERVED = 0x00004000; /* old flag for 4.1 protocol  */
+exports.SECURE_CONNECTION = 0x00008000; /* new 4.1 authentication */
+exports.MULTI_STATEMENTS = 0x00010000; /* enable/disable multi-stmt support */
+exports.MULTI_RESULTS = 0x00020000; /* enable/disable multi-results */
+exports.PS_MULTI_RESULTS = 0x00040000; /* multi-results in ps-protocol */
+exports.PLUGIN_AUTH = 0x00080000; /* client supports plugin authentication */
+exports.CONNECT_ATTRS = 0x00100000; /* permits connection attributes */
+exports.PLUGIN_AUTH_LENENC_CLIENT_DATA = 0x00200000; /* Understands length-encoded integer for auth response data in Protocol::HandshakeResponse41. */
+exports.CAN_HANDLE_EXPIRED_PASSWORDS = 0x00400000; /* Announces support for expired password extension. */
+exports.SESSION_TRACK = 0x00800000; /* Can set SERVER_SESSION_STATE_CHANGED in the Status Flags and send session-state change data after a OK packet. */
+exports.CLIENT_QUERY_ATTRIBUTES = 0x08000000; /* support query attributes in COM_QUERY and COM_STMT_EXECUTE */
+
+exports.SSL_VERIFY_SERVER_CERT = 0x40000000;
+exports.REMEMBER_OPTIONS = 0x80000000;
+
+exports.MULTI_FACTOR_AUTHENTICATION = 0x10000000; /* multi-factor authentication */

backend/node_modules/mysql2/lib/constants/commands.js

@@ -0,0 +1,37 @@
+'use strict';
+
+module.exports = {
+  SLEEP: 0x00, // deprecated
+  QUIT: 0x01,
+  INIT_DB: 0x02,
+  QUERY: 0x03,
+  FIELD_LIST: 0x04,
+  CREATE_DB: 0x05,
+  DROP_DB: 0x06,
+  REFRESH: 0x07,
+  SHUTDOWN: 0x08,
+  STATISTICS: 0x09,
+  PROCESS_INFO: 0x0a, // deprecated
+  CONNECT: 0x0b, // deprecated
+  PROCESS_KILL: 0x0c,
+  DEBUG: 0x0d,
+  PING: 0x0e,
+  TIME: 0x0f, // deprecated
+  DELAYED_INSERT: 0x10, // deprecated
+  CHANGE_USER: 0x11,
+  BINLOG_DUMP: 0x12,
+  TABLE_DUMP: 0x13,
+  CONNECT_OUT: 0x14,
+  REGISTER_SLAVE: 0x15,
+  STMT_PREPARE: 0x16,
+  STMT_EXECUTE: 0x17,
+  STMT_SEND_LONG_DATA: 0x18,
+  STMT_CLOSE: 0x19,
+  STMT_RESET: 0x1a,
+  SET_OPTION: 0x1b,
+  STMT_FETCH: 0x1c,
+  DAEMON: 0x1d, // deprecated
+  BINLOG_DUMP_GTID: 0x1e,
+  RESET_CONNECTION: 0x1f, // introduced in 5.7.3
+  UNKNOWN: 0xff, // bad!
+};

backend/node_modules/mysql2/lib/constants/cursor.js

@@ -0,0 +1,9 @@
+'use strict';
+
+module.exports = {
+  NO_CURSOR: 0,
+  READ_ONLY: 1,
+  FOR_UPDATE: 2,
+  SCROLLABLE: 3,
+  PARAMETER_COUNT_AVAILABLE: 8,
+};

backend/node_modules/mysql2/lib/constants/encoding_charset.js

@@ -0,0 +1,50 @@
+'use strict';
+
+// inverse of charset_encodings
+// given encoding, get matching mysql charset number
+
+module.exports = {
+  big5: 1,
+  latin2: 2,
+  dec8: 3,
+  cp850: 4,
+  latin1: 5,
+  hp8: 6,
+  koi8r: 7,
+  swe7: 10,
+  ascii: 11,
+  eucjp: 12,
+  sjis: 13,
+  cp1251: 14,
+  hebrew: 16,
+  tis620: 18,
+  euckr: 19,
+  latin7: 20,
+  koi8u: 22,
+  gb2312: 24,
+  greek: 25,
+  cp1250: 26,
+  gbk: 28,
+  cp1257: 29,
+  latin5: 30,
+  armscii8: 32,
+  cesu8: 33,
+  ucs2: 35,
+  cp866: 36,
+  keybcs2: 37,
+  macintosh: 38,
+  macroman: 39,
+  cp852: 40,
+  utf8: 45,
+  utf8mb4: 45,
+  utf16: 54,
+  utf16le: 56,
+  cp1256: 57,
+  utf32: 60,
+  binary: 63,
+  geostd8: 92,
+  cp932: 95,
+  eucjpms: 97,
+  gb18030: 248,
+  utf8mb3: 192,
+};

backend/node_modules/mysql2/lib/constants/field_flags.js

@@ -0,0 +1,20 @@
+'use strict';
+
+// Manually extracted from mysql-5.5.23/include/mysql_com.h
+exports.NOT_NULL = 1; /* Field can't be NULL */
+exports.PRI_KEY = 2; /* Field is part of a primary key */
+exports.UNIQUE_KEY = 4; /* Field is part of a unique key */
+exports.MULTIPLE_KEY = 8; /* Field is part of a key */
+exports.BLOB = 16; /* Field is a blob */
+exports.UNSIGNED = 32; /* Field is unsigned */
+exports.ZEROFILL = 64; /* Field is zerofill */
+exports.BINARY = 128; /* Field is binary   */
+
+/* The following are only sent to new clients */
+exports.ENUM = 256; /* field is an enum */
+exports.AUTO_INCREMENT = 512; /* field is a autoincrement field */
+exports.TIMESTAMP = 1024; /* Field is a timestamp */
+exports.SET = 2048; /* field is a set */
+exports.NO_DEFAULT_VALUE = 4096; /* Field doesn't have default value */
+exports.ON_UPDATE_NOW = 8192; /* Field is set to NOW on UPDATE */
+exports.NUM = 32768; /* Field is num (for clients) */

backend/node_modules/mysql2/lib/constants/server_status.js

@@ -0,0 +1,44 @@
+'use strict';
+
+// Manually extracted from mysql-5.5.23/include/mysql_com.h
+
+/**
+  Is raised when a multi-statement transaction
+  has been started, either explicitly, by means
+  of BEGIN or COMMIT AND CHAIN, or
+  implicitly, by the first transactional
+  statement, when autocommit=off.
+*/
+exports.SERVER_STATUS_IN_TRANS = 1;
+exports.SERVER_STATUS_AUTOCOMMIT = 2; /* Server in auto_commit mode */
+exports.SERVER_MORE_RESULTS_EXISTS = 8; /* Multi query - next query exists */
+exports.SERVER_QUERY_NO_GOOD_INDEX_USED = 16;
+exports.SERVER_QUERY_NO_INDEX_USED = 32;
+/**
+  The server was able to fulfill the clients request and opened a
+  read-only non-scrollable cursor for a query. This flag comes
+  in reply to COM_STMT_EXECUTE and COM_STMT_FETCH commands.
+*/
+exports.SERVER_STATUS_CURSOR_EXISTS = 64;
+/**
+  This flag is sent when a read-only cursor is exhausted, in reply to
+  COM_STMT_FETCH command.
+*/
+exports.SERVER_STATUS_LAST_ROW_SENT = 128;
+exports.SERVER_STATUS_DB_DROPPED = 256; /* A database was dropped */
+exports.SERVER_STATUS_NO_BACKSLASH_ESCAPES = 512;
+/**
+  Sent to the client if after a prepared statement reprepare
+  we discovered that the new statement returns a different
+  number of result set columns.
+*/
+exports.SERVER_STATUS_METADATA_CHANGED = 1024;
+exports.SERVER_QUERY_WAS_SLOW = 2048;
+
+/**
+  To mark ResultSet containing output parameter values.
+*/
+exports.SERVER_PS_OUT_PARAMS = 4096;
+
+exports.SERVER_STATUS_IN_TRANS_READONLY = 0x2000; // in a read-only transaction
+exports.SERVER_SESSION_STATE_CHANGED = 0x4000;

backend/node_modules/mysql2/lib/constants/session_track.js

@@ -0,0 +1,11 @@
+'use strict';
+
+exports.SYSTEM_VARIABLES = 0;
+exports.SCHEMA = 1;
+exports.STATE_CHANGE = 2;
+exports.STATE_GTIDS = 3;
+exports.TRANSACTION_CHARACTERISTICS = 4;
+exports.TRANSACTION_STATE = 5;
+
+exports.FIRST_KEY = exports.SYSTEM_VARIABLES;
+exports.LAST_KEY = exports.TRANSACTION_STATE;

backend/node_modules/mysql2/lib/constants/ssl_profiles.js

@@ -0,0 +1,11 @@
+'use strict';
+
+const awsCaBundle = require('aws-ssl-profiles');
+
+/**
+ * @deprecated
+ * Please, use [**aws-ssl-profiles**](https://github.com/mysqljs/aws-ssl-profiles).
+ */
+exports['Amazon RDS'] = {
+  ca: awsCaBundle.ca,
+};

backend/node_modules/mysql2/lib/constants/types.js

@@ -0,0 +1,64 @@
+'use strict';
+
+module.exports = {
+  0x00: 'DECIMAL', // aka DECIMAL
+  0x01: 'TINY', // aka TINYINT, 1 byte
+  0x02: 'SHORT', // aka SMALLINT, 2 bytes
+  0x03: 'LONG', // aka INT, 4 bytes
+  0x04: 'FLOAT', // aka FLOAT, 4-8 bytes
+  0x05: 'DOUBLE', // aka DOUBLE, 8 bytes
+  0x06: 'NULL', // NULL (used for prepared statements, I think)
+  0x07: 'TIMESTAMP', // aka TIMESTAMP
+  0x08: 'LONGLONG', // aka BIGINT, 8 bytes
+  0x09: 'INT24', // aka MEDIUMINT, 3 bytes
+  0x0a: 'DATE', // aka DATE
+  0x0b: 'TIME', // aka TIME
+  0x0c: 'DATETIME', // aka DATETIME
+  0x0d: 'YEAR', // aka YEAR, 1 byte (don't ask)
+  0x0e: 'NEWDATE', // aka ?
+  0x0f: 'VARCHAR', // aka VARCHAR (?)
+  0x10: 'BIT', // aka BIT, 1-8 byte
+  0xf5: 'JSON',
+  0xf6: 'NEWDECIMAL', // aka DECIMAL
+  0xf7: 'ENUM', // aka ENUM
+  0xf8: 'SET', // aka SET
+  0xf9: 'TINY_BLOB', // aka TINYBLOB, TINYTEXT
+  0xfa: 'MEDIUM_BLOB', // aka MEDIUMBLOB, MEDIUMTEXT
+  0xfb: 'LONG_BLOB', // aka LONGBLOG, LONGTEXT
+  0xfc: 'BLOB', // aka BLOB, TEXT
+  0xfd: 'VAR_STRING', // aka VARCHAR, VARBINARY
+  0xfe: 'STRING', // aka CHAR, BINARY
+  0xff: 'GEOMETRY', // aka GEOMETRY
+};
+
+// Manually extracted from mysql-5.5.23/include/mysql_com.h
+// some more info here: http://dev.mysql.com/doc/refman/5.5/en/c-api-prepared-statement-type-codes.html
+module.exports.DECIMAL = 0x00; // aka DECIMAL (http://dev.mysql.com/doc/refman/5.0/en/precision-math-decimal-changes.html)
+module.exports.TINY = 0x01; // aka TINYINT, 1 byte
+module.exports.SHORT = 0x02; // aka SMALLINT, 2 bytes
+module.exports.LONG = 0x03; // aka INT, 4 bytes
+module.exports.FLOAT = 0x04; // aka FLOAT, 4-8 bytes
+module.exports.DOUBLE = 0x05; // aka DOUBLE, 8 bytes
+module.exports.NULL = 0x06; // NULL (used for prepared statements, I think)
+module.exports.TIMESTAMP = 0x07; // aka TIMESTAMP
+module.exports.LONGLONG = 0x08; // aka BIGINT, 8 bytes
+module.exports.INT24 = 0x09; // aka MEDIUMINT, 3 bytes
+module.exports.DATE = 0x0a; // aka DATE
+module.exports.TIME = 0x0b; // aka TIME
+module.exports.DATETIME = 0x0c; // aka DATETIME
+module.exports.YEAR = 0x0d; // aka YEAR, 1 byte (don't ask)
+module.exports.NEWDATE = 0x0e; // aka ?
+module.exports.VARCHAR = 0x0f; // aka VARCHAR (?)
+module.exports.BIT = 0x10; // aka BIT, 1-8 byte
+module.exports.VECTOR = 0xf2;
+module.exports.JSON = 0xf5;
+module.exports.NEWDECIMAL = 0xf6; // aka DECIMAL
+module.exports.ENUM = 0xf7; // aka ENUM
+module.exports.SET = 0xf8; // aka SET
+module.exports.TINY_BLOB = 0xf9; // aka TINYBLOB, TINYTEXT
+module.exports.MEDIUM_BLOB = 0xfa; // aka MEDIUMBLOB, MEDIUMTEXT
+module.exports.LONG_BLOB = 0xfb; // aka LONGBLOG, LONGTEXT
+module.exports.BLOB = 0xfc; // aka BLOB, TEXT
+module.exports.VAR_STRING = 0xfd; // aka VARCHAR, VARBINARY
+module.exports.STRING = 0xfe; // aka CHAR, BINARY
+module.exports.GEOMETRY = 0xff; // aka GEOMETRY

backend/node_modules/mysql2/lib/create_connection.js

@@ -0,0 +1,10 @@
+'use strict';
+
+const Connection = require('./connection.js');
+const ConnectionConfig = require('./connection_config.js');
+
+function createConnection(opts) {
+  return new Connection({ config: new ConnectionConfig(opts) });
+}
+
+module.exports = createConnection;

backend/node_modules/mysql2/lib/create_pool.js

@@ -0,0 +1,10 @@
+'use strict';
+
+const Pool = require('./pool.js');
+const PoolConfig = require('./pool_config.js');
+
+function createPool(config) {
+  return new Pool({ config: new PoolConfig(config) });
+}
+
+module.exports = createPool;

backend/node_modules/mysql2/lib/create_pool_cluster.js

@@ -0,0 +1,9 @@
+'use strict';
+
+const PoolCluster = require('./pool_cluster.js');
+
+function createPoolCluster(config) {
+  return new PoolCluster(config);
+}
+
+module.exports = createPoolCluster;

backend/node_modules/mysql2/lib/helpers.js

@@ -0,0 +1,83 @@
+'use strict';
+
+/*
+
+  this seems to be not only shorter, but faster than
+  string.replace(/\\/g, '\\\\').
+            replace(/\u0008/g, '\\b').
+            replace(/\t/g, '\\t').
+            replace(/\n/g, '\\n').
+            replace(/\f/g, '\\f').
+            replace(/\r/g, '\\r').
+            replace(/'/g, '\\\'').
+            replace(/"/g, '\\"');
+  or string.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&")
+  see http://jsperf.com/string-escape-regexp-vs-json-stringify
+  */
+function srcEscape(str) {
+  return JSON.stringify({
+    [str]: 1,
+  }).slice(1, -3);
+}
+
+exports.srcEscape = srcEscape;
+
+let highlightFn;
+let cardinalRecommended = false;
+try {
+  // the purpose of this is to prevent projects using Webpack from displaying a warning during runtime if cardinal is not a dependency
+  const REQUIRE_TERMINATOR = '';
+  highlightFn = require(`cardinal${REQUIRE_TERMINATOR}`).highlight;
+} catch {
+  highlightFn = (text) => {
+    if (!cardinalRecommended) {
+      console.log('For nicer debug output consider install cardinal@^2.0.0');
+      cardinalRecommended = true;
+    }
+    return text;
+  };
+}
+
+/**
+ * Prints debug message with code frame, will try to use `cardinal` if available.
+ */
+function printDebugWithCode(msg, code) {
+  console.log(`\n\n${msg}:\n`);
+  console.log(`${highlightFn(code)}\n`);
+}
+
+exports.printDebugWithCode = printDebugWithCode;
+
+/**
+ * checks whether the `type` is in the `list`
+ */
+function typeMatch(type, list, Types) {
+  if (Array.isArray(list)) {
+    return list.some((t) => type === Types[t]);
+  }
+
+  return !!list;
+}
+
+exports.typeMatch = typeMatch;
+
+const privateObjectProps = new Set([
+  '__defineGetter__',
+  '__defineSetter__',
+  '__lookupGetter__',
+  '__lookupSetter__',
+  '__proto__',
+]);
+
+exports.privateObjectProps = privateObjectProps;
+
+const fieldEscape = (field, isEval = true) => {
+  if (privateObjectProps.has(field)) {
+    throw new Error(
+      `The field name (${field}) can't be the same as an object's private property.`
+    );
+  }
+
+  return isEval ? srcEscape(field) : field;
+};
+exports.fieldEscape = fieldEscape;

backend/node_modules/mysql2/lib/packet_parser.js

@@ -0,0 +1,195 @@
+'use strict';
+
+const Packet = require('./packets/packet.js');
+
+const MAX_PACKET_LENGTH = 16777215;
+
+function readPacketLength(b, off) {
+  const b0 = b[off];
+  const b1 = b[off + 1];
+  const b2 = b[off + 2];
+  if (b1 + b2 === 0) {
+    return b0;
+  }
+  return b0 + (b1 << 8) + (b2 << 16);
+}
+
+class PacketParser {
+  constructor(onPacket, packetHeaderLength) {
+    // 4 for normal packets, 7 for comprssed protocol packets
+    if (typeof packetHeaderLength === 'undefined') {
+      packetHeaderLength = 4;
+    }
+    // array of last payload chunks
+    // only used when current payload is not complete
+    this.buffer = [];
+    // total length of chunks on buffer
+    this.bufferLength = 0;
+    this.packetHeaderLength = packetHeaderLength;
+    // incomplete header state: number of header bytes received
+    this.headerLen = 0;
+    // expected payload length
+    this.length = 0;
+    this.largePacketParts = [];
+    this.firstPacketSequenceId = 0;
+    this.onPacket = onPacket;
+    this.execute = PacketParser.prototype.executeStart;
+    this._flushLargePacket =
+      packetHeaderLength === 7
+        ? this._flushLargePacket7
+        : this._flushLargePacket4;
+  }
+
+  _flushLargePacket4() {
+    const numPackets = this.largePacketParts.length;
+    this.largePacketParts.unshift(Buffer.from([0, 0, 0, 0])); // insert header
+    const body = Buffer.concat(this.largePacketParts);
+    const packet = new Packet(this.firstPacketSequenceId, body, 0, body.length);
+    this.largePacketParts.length = 0;
+    packet.numPackets = numPackets;
+    this.onPacket(packet);
+  }
+
+  _flushLargePacket7() {
+    const numPackets = this.largePacketParts.length;
+    this.largePacketParts.unshift(Buffer.from([0, 0, 0, 0, 0, 0, 0])); // insert header
+    const body = Buffer.concat(this.largePacketParts);
+    this.largePacketParts.length = 0;
+    const packet = new Packet(this.firstPacketSequenceId, body, 0, body.length);
+    packet.numPackets = numPackets;
+    this.onPacket(packet);
+  }
+
+  executeStart(chunk) {
+    let start = 0;
+    const end = chunk.length;
+    while (end - start >= 3) {
+      this.length = readPacketLength(chunk, start);
+      if (end - start >= this.length + this.packetHeaderLength) {
+        // at least one full packet
+        const sequenceId = chunk[start + 3];
+        if (
+          this.length < MAX_PACKET_LENGTH &&
+          this.largePacketParts.length === 0
+        ) {
+          this.onPacket(
+            new Packet(
+              sequenceId,
+              chunk,
+              start,
+              start + this.packetHeaderLength + this.length
+            )
+          );
+        } else {
+          // first large packet - remember it's id
+          if (this.largePacketParts.length === 0) {
+            this.firstPacketSequenceId = sequenceId;
+          }
+          this.largePacketParts.push(
+            chunk.slice(
+              start + this.packetHeaderLength,
+              start + this.packetHeaderLength + this.length
+            )
+          );
+          if (this.length < MAX_PACKET_LENGTH) {
+            this._flushLargePacket();
+          }
+        }
+        start += this.packetHeaderLength + this.length;
+      } else {
+        // payload is incomplete
+        this.buffer = [chunk.slice(start + 3, end)];
+        this.bufferLength = end - start - 3;
+        this.execute = PacketParser.prototype.executePayload;
+        return;
+      }
+    }
+    if (end - start > 0) {
+      // there is start of length header, but it's not full 3 bytes
+      this.headerLen = end - start; // 1 or 2 bytes
+      this.length = chunk[start];
+      if (this.headerLen === 2) {
+        this.length = chunk[start] + (chunk[start + 1] << 8);
+        this.execute = PacketParser.prototype.executeHeader3;
+      } else {
+        this.execute = PacketParser.prototype.executeHeader2;
+      }
+    }
+  }
+
+  executePayload(chunk) {
+    let start = 0;
+    const end = chunk.length;
+    const remainingPayload =
+      this.length - this.bufferLength + this.packetHeaderLength - 3;
+    if (end - start >= remainingPayload) {
+      // last chunk for payload
+      const payload = Buffer.allocUnsafe(this.length + this.packetHeaderLength);
+      let offset = 3;
+      for (let i = 0; i < this.buffer.length; ++i) {
+        this.buffer[i].copy(payload, offset);
+        offset += this.buffer[i].length;
+      }
+      chunk.copy(payload, offset, start, start + remainingPayload);
+      const sequenceId = payload[3];
+      if (
+        this.length < MAX_PACKET_LENGTH &&
+        this.largePacketParts.length === 0
+      ) {
+        this.onPacket(
+          new Packet(
+            sequenceId,
+            payload,
+            0,
+            this.length + this.packetHeaderLength
+          )
+        );
+      } else {
+        // first large packet - remember it's id
+        if (this.largePacketParts.length === 0) {
+          this.firstPacketSequenceId = sequenceId;
+        }
+        this.largePacketParts.push(
+          payload.slice(
+            this.packetHeaderLength,
+            this.packetHeaderLength + this.length
+          )
+        );
+        if (this.length < MAX_PACKET_LENGTH) {
+          this._flushLargePacket();
+        }
+      }
+      this.buffer = [];
+      this.bufferLength = 0;
+      this.execute = PacketParser.prototype.executeStart;
+      start += remainingPayload;
+      if (end - start > 0) {
+        return this.execute(chunk.slice(start, end));
+      }
+    } else {
+      this.buffer.push(chunk);
+      this.bufferLength += chunk.length;
+    }
+    return null;
+  }
+
+  executeHeader2(chunk) {
+    this.length += chunk[0] << 8;
+    if (chunk.length > 1) {
+      this.length += chunk[1] << 16;
+      this.execute = PacketParser.prototype.executePayload;
+      return this.executePayload(chunk.slice(2));
+    }
+    this.execute = PacketParser.prototype.executeHeader3;
+
+    return null;
+  }
+
+  executeHeader3(chunk) {
+    this.length += chunk[0] << 16;
+    this.execute = PacketParser.prototype.executePayload;
+    return this.executePayload(chunk.slice(1));
+  }
+}
+
+module.exports = PacketParser;

backend/node_modules/mysql2/lib/packets/auth_next_factor.js

@@ -0,0 +1,35 @@
+// Copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+const Packet = require('../packets/packet');
+
+class AuthNextFactor {
+  constructor(opts) {
+    this.pluginName = opts.pluginName;
+    this.pluginData = opts.pluginData;
+  }
+
+  toPacket(encoding) {
+    const length = 6 + this.pluginName.length + this.pluginData.length;
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeInt8(0x02);
+    packet.writeNullTerminatedString(this.pluginName, encoding);
+    packet.writeBuffer(this.pluginData);
+    return packet;
+  }
+
+  static fromPacket(packet, encoding) {
+    packet.readInt8(); // marker
+    const name = packet.readNullTerminatedString(encoding);
+    const data = packet.readBuffer();
+    return new AuthNextFactor({
+      pluginName: name,
+      pluginData: data,
+    });
+  }
+}
+
+module.exports = AuthNextFactor;

backend/node_modules/mysql2/lib/packets/auth_switch_request.js

@@ -0,0 +1,38 @@
+'use strict';
+
+// http://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchRequest
+
+const Packet = require('../packets/packet');
+
+class AuthSwitchRequest {
+  constructor(opts) {
+    this.pluginName = opts.pluginName;
+    this.pluginData = opts.pluginData;
+  }
+
+  toPacket() {
+    const length = 6 + this.pluginName.length + this.pluginData.length;
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeInt8(0xfe);
+    // TODO: use server encoding
+    packet.writeNullTerminatedString(this.pluginName, 'cesu8');
+    packet.writeBuffer(this.pluginData);
+    return packet;
+  }
+
+  static fromPacket(packet) {
+    packet.readInt8(); // marker
+    // assert marker == 0xfe?
+    // TODO: use server encoding
+    const name = packet.readNullTerminatedString('cesu8');
+    const data = packet.readBuffer();
+    return new AuthSwitchRequest({
+      pluginName: name,
+      pluginData: data,
+    });
+  }
+}
+
+module.exports = AuthSwitchRequest;

backend/node_modules/mysql2/lib/packets/auth_switch_request_more_data.js

@@ -0,0 +1,33 @@
+'use strict';
+
+// http://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchRequest
+
+const Packet = require('../packets/packet');
+
+class AuthSwitchRequestMoreData {
+  constructor(data) {
+    this.data = data;
+  }
+
+  toPacket() {
+    const length = 5 + this.data.length;
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeInt8(0x01);
+    packet.writeBuffer(this.data);
+    return packet;
+  }
+
+  static fromPacket(packet) {
+    packet.readInt8(); // marker
+    const data = packet.readBuffer();
+    return new AuthSwitchRequestMoreData(data);
+  }
+
+  static verifyMarker(packet) {
+    return packet.peekByte() === 0x01;
+  }
+}
+
+module.exports = AuthSwitchRequestMoreData;

backend/node_modules/mysql2/lib/packets/auth_switch_response.js

@@ -0,0 +1,30 @@
+'use strict';
+
+// http://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchRequest
+
+const Packet = require('../packets/packet');
+
+class AuthSwitchResponse {
+  constructor(data) {
+    if (!Buffer.isBuffer(data)) {
+      data = Buffer.from(data);
+    }
+    this.data = data;
+  }
+
+  toPacket() {
+    const length = 4 + this.data.length;
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeBuffer(this.data);
+    return packet;
+  }
+
+  static fromPacket(packet) {
+    const data = packet.readBuffer();
+    return new AuthSwitchResponse(data);
+  }
+}
+
+module.exports = AuthSwitchResponse;

backend/node_modules/mysql2/lib/packets/binary_row.js

@@ -0,0 +1,95 @@
+'use strict';
+
+const Types = require('../constants/types');
+const Packet = require('../packets/packet');
+
+const binaryReader = new Array(256);
+
+class BinaryRow {
+  constructor(columns) {
+    this.columns = columns || [];
+  }
+
+  static toPacket(columns, encoding) {
+    // throw new Error('Not implemented');
+    const sequenceId = 0; // TODO remove, this is calculated now in connecton
+    let length = 0;
+    columns.forEach((val) => {
+      if (val === null || typeof val === 'undefined') {
+        ++length;
+        return;
+      }
+      length += Packet.lengthCodedStringLength(val.toString(10), encoding);
+    });
+
+    length = length + 2;
+
+    const buffer = Buffer.allocUnsafe(length + 4);
+    const packet = new Packet(sequenceId, buffer, 0, length + 4);
+    packet.offset = 4;
+
+    packet.writeInt8(0);
+
+    let bitmap = 0;
+    let bitValue = 1;
+    columns.forEach((parameter) => {
+      if (parameter.type === Types.NULL) {
+        bitmap += bitValue;
+      }
+      bitValue *= 2;
+      if (bitValue === 256) {
+        packet.writeInt8(bitmap);
+        bitmap = 0;
+        bitValue = 1;
+      }
+    });
+    if (bitValue !== 1) {
+      packet.writeInt8(bitmap);
+    }
+
+    columns.forEach((val) => {
+      if (val === null) {
+        packet.writeNull();
+        return;
+      }
+      if (typeof val === 'undefined') {
+        packet.writeInt8(0);
+        return;
+      }
+      packet.writeLengthCodedString(val.toString(10), encoding);
+    });
+    return packet;
+  }
+
+  // TODO: complete list of types...
+  static fromPacket(fields, packet) {
+    const columns = new Array(fields.length);
+    packet.readInt8(); // TODO check it's 0
+    const nullBitmapLength = Math.floor((fields.length + 7 + 2) / 8);
+    // TODO: read and interpret null bitmap
+    packet.skip(nullBitmapLength);
+    for (let i = 0; i < columns.length; ++i) {
+      columns[i] = binaryReader[fields[i].columnType].apply(packet);
+    }
+    return new BinaryRow(columns);
+  }
+}
+
+// TODO: replace with constants.MYSQL_TYPE_*
+binaryReader[Types.DECIMAL] = Packet.prototype.readLengthCodedString;
+binaryReader[1] = Packet.prototype.readInt8; // tiny
+binaryReader[2] = Packet.prototype.readInt16; // short
+binaryReader[3] = Packet.prototype.readInt32; // long
+binaryReader[4] = Packet.prototype.readFloat; // float
+binaryReader[5] = Packet.prototype.readDouble; // double
+binaryReader[6] = Packet.prototype.assertInvalid; // null, should be skipped vie null bitmap
+binaryReader[7] = Packet.prototype.readTimestamp; // timestamp, http://dev.mysql.com/doc/internals/en/prepared-statements.html#packet-ProtocolBinary::MYSQL_TYPE_TIMESTAMP
+binaryReader[8] = Packet.prototype.readInt64; // long long
+binaryReader[9] = Packet.prototype.readInt32; // int24
+binaryReader[10] = Packet.prototype.readTimestamp; // date
+binaryReader[11] = Packet.prototype.readTime; // time, http://dev.mysql.com/doc/internals/en/prepared-statements.html#packet-ProtocolBinary::MYSQL_TYPE_TIME
+binaryReader[12] = Packet.prototype.readDateTime; // datetime, http://dev.mysql.com/doc/internals/en/prepared-statements.html#packet-ProtocolBinary::MYSQL_TYPE_DATETIME
+binaryReader[13] = Packet.prototype.readInt16; // year
+binaryReader[Types.VAR_STRING] = Packet.prototype.readLengthCodedString; // var string
+
+module.exports = BinaryRow;

backend/node_modules/mysql2/lib/packets/binlog_dump.js

@@ -0,0 +1,33 @@
+'use strict';
+
+// http://dev.mysql.com/doc/internals/en/com-binlog-dump.html#packet-COM_BINLOG_DUMP
+
+const Packet = require('../packets/packet');
+const CommandCodes = require('../constants/commands');
+
+// TODO: add flag to constants
+// 0x01 - BINLOG_DUMP_NON_BLOCK
+// send EOF instead of blocking
+class BinlogDump {
+  constructor(opts) {
+    this.binlogPos = opts.binlogPos || 0;
+    this.serverId = opts.serverId || 0;
+    this.flags = opts.flags || 0;
+    this.filename = opts.filename || '';
+  }
+
+  toPacket() {
+    const length = 15 + Buffer.byteLength(this.filename, 'utf8'); // TODO: should be ascii?
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeInt8(CommandCodes.BINLOG_DUMP);
+    packet.writeInt32(this.binlogPos);
+    packet.writeInt16(this.flags);
+    packet.writeInt32(this.serverId);
+    packet.writeString(this.filename);
+    return packet;
+  }
+}
+
+module.exports = BinlogDump;

backend/node_modules/mysql2/lib/packets/binlog_query_statusvars.js

@@ -0,0 +1,115 @@
+'use strict';
+
+// http://dev.mysql.com/doc/internals/en/query-event.html
+
+const keys = {
+  FLAGS2: 0,
+  SQL_MODE: 1,
+  CATALOG: 2,
+  AUTO_INCREMENT: 3,
+  CHARSET: 4,
+  TIME_ZONE: 5,
+  CATALOG_NZ: 6,
+  LC_TIME_NAMES: 7,
+  CHARSET_DATABASE: 8,
+  TABLE_MAP_FOR_UPDATE: 9,
+  MASTER_DATA_WRITTEN: 10,
+  INVOKERS: 11,
+  UPDATED_DB_NAMES: 12,
+  MICROSECONDS: 3,
+};
+
+module.exports = function parseStatusVars(buffer) {
+  const result = {};
+  let offset = 0;
+  let key, length, prevOffset;
+  while (offset < buffer.length) {
+    key = buffer[offset++];
+    switch (key) {
+      case keys.FLAGS2:
+        result.flags = buffer.readUInt32LE(offset);
+        offset += 4;
+        break;
+      case keys.SQL_MODE:
+        // value is 8 bytes, but all dcumented flags are in first 4 bytes
+        result.sqlMode = buffer.readUInt32LE(offset);
+        offset += 8;
+        break;
+      case keys.CATALOG:
+        length = buffer[offset++];
+        result.catalog = buffer.toString('utf8', offset, offset + length);
+        offset += length + 1; // null byte after string
+        break;
+      case keys.CHARSET:
+        result.clientCharset = buffer.readUInt16LE(offset);
+        result.connectionCollation = buffer.readUInt16LE(offset + 2);
+        result.serverCharset = buffer.readUInt16LE(offset + 4);
+        offset += 6;
+        break;
+      case keys.TIME_ZONE:
+        length = buffer[offset++];
+        result.timeZone = buffer.toString('utf8', offset, offset + length);
+        offset += length; // no null byte
+        break;
+      case keys.CATALOG_NZ:
+        length = buffer[offset++];
+        result.catalogNz = buffer.toString('utf8', offset, offset + length);
+        offset += length; // no null byte
+        break;
+      case keys.LC_TIME_NAMES:
+        result.lcTimeNames = buffer.readUInt16LE(offset);
+        offset += 2;
+        break;
+      case keys.CHARSET_DATABASE:
+        result.schemaCharset = buffer.readUInt16LE(offset);
+        offset += 2;
+        break;
+      case keys.TABLE_MAP_FOR_UPDATE:
+        result.mapForUpdate1 = buffer.readUInt32LE(offset);
+        result.mapForUpdate2 = buffer.readUInt32LE(offset + 4);
+        offset += 8;
+        break;
+      case keys.MASTER_DATA_WRITTEN:
+        result.masterDataWritten = buffer.readUInt32LE(offset);
+        offset += 4;
+        break;
+      case keys.INVOKERS:
+        length = buffer[offset++];
+        result.invokerUsername = buffer.toString(
+          'utf8',
+          offset,
+          offset + length
+        );
+        offset += length;
+        length = buffer[offset++];
+        result.invokerHostname = buffer.toString(
+          'utf8',
+          offset,
+          offset + length
+        );
+        offset += length;
+        break;
+      case keys.UPDATED_DB_NAMES:
+        length = buffer[offset++];
+        // length - number of null-terminated strings
+        result.updatedDBs = []; // we'll store them as array here
+        for (; length; --length) {
+          prevOffset = offset;
+          // fast forward to null terminating byte
+          while (buffer[offset++] && offset < buffer.length) {
+            // empty body, everything inside while condition
+          }
+          result.updatedDBs.push(
+            buffer.toString('utf8', prevOffset, offset - 1)
+          );
+        }
+        break;
+      case keys.MICROSECONDS:
+        result.microseconds =
+          // REVIEW: INVALID UNKNOWN VARIABLE!
+          buffer.readInt16LE(offset) + (buffer[offset + 2] << 16);
+        offset += 3;
+    }
+  }
+  return result;
+};

backend/node_modules/mysql2/lib/packets/change_user.js

@@ -0,0 +1,97 @@
+'use strict';
+
+const CommandCode = require('../constants/commands.js');
+const ClientConstants = require('../constants/client.js');
+const Packet = require('../packets/packet.js');
+const auth41 = require('../auth_41.js');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+
+// https://dev.mysql.com/doc/internals/en/com-change-user.html#packet-COM_CHANGE_USER
+class ChangeUser {
+  constructor(opts) {
+    this.flags = opts.flags;
+    this.user = opts.user || '';
+    this.database = opts.database || '';
+    this.password = opts.password || '';
+    this.passwordSha1 = opts.passwordSha1;
+    this.authPluginData1 = opts.authPluginData1;
+    this.authPluginData2 = opts.authPluginData2;
+    this.connectAttributes = opts.connectAttrinutes || {};
+    let authToken;
+    if (this.passwordSha1) {
+      authToken = auth41.calculateTokenFromPasswordSha(
+        this.passwordSha1,
+        this.authPluginData1,
+        this.authPluginData2
+      );
+    } else {
+      authToken = auth41.calculateToken(
+        this.password,
+        this.authPluginData1,
+        this.authPluginData2
+      );
+    }
+    this.authToken = authToken;
+    this.charsetNumber = opts.charsetNumber;
+  }
+
+  // TODO
+  // ChangeUser.fromPacket = function(packet)
+  // };
+  serializeToBuffer(buffer) {
+    const isSet = (flag) => this.flags & ClientConstants[flag];
+    const packet = new Packet(0, buffer, 0, buffer.length);
+    packet.offset = 4;
+    const encoding = CharsetToEncoding[this.charsetNumber];
+    packet.writeInt8(CommandCode.CHANGE_USER);
+    packet.writeNullTerminatedString(this.user, encoding);
+    if (isSet('SECURE_CONNECTION')) {
+      packet.writeInt8(this.authToken.length);
+      packet.writeBuffer(this.authToken);
+    } else {
+      packet.writeBuffer(this.authToken);
+      packet.writeInt8(0);
+    }
+    packet.writeNullTerminatedString(this.database, encoding);
+    packet.writeInt16(this.charsetNumber);
+    if (isSet('PLUGIN_AUTH')) {
+      // TODO: read this from parameters
+      packet.writeNullTerminatedString('mysql_native_password', 'latin1');
+    }
+    if (isSet('CONNECT_ATTRS')) {
+      const connectAttributes = this.connectAttributes;
+      const attrNames = Object.keys(connectAttributes);
+      let keysLength = 0;
+      for (let k = 0; k < attrNames.length; ++k) {
+        keysLength += Packet.lengthCodedStringLength(attrNames[k], encoding);
+        keysLength += Packet.lengthCodedStringLength(
+          connectAttributes[attrNames[k]],
+          encoding
+        );
+      }
+      packet.writeLengthCodedNumber(keysLength);
+      for (let k = 0; k < attrNames.length; ++k) {
+        packet.writeLengthCodedString(attrNames[k], encoding);
+        packet.writeLengthCodedString(
+          connectAttributes[attrNames[k]],
+          encoding
+        );
+      }
+    }
+    return packet;
+  }
+
+  toPacket() {
+    if (typeof this.user !== 'string') {
+      throw new Error('"user" connection config property must be a string');
+    }
+    if (typeof this.database !== 'string') {
+      throw new Error('"database" connection config property must be a string');
+    }
+    // dry run: calculate resulting packet length
+    const p = this.serializeToBuffer(Packet.MockBuffer());
+    return this.serializeToBuffer(Buffer.allocUnsafe(p.offset));
+  }
+}
+
+module.exports = ChangeUser;

backend/node_modules/mysql2/lib/packets/close_statement.js

@@ -0,0 +1,21 @@
+'use strict';
+
+const Packet = require('../packets/packet');
+const CommandCodes = require('../constants/commands');
+
+class CloseStatement {
+  constructor(id) {
+    this.id = id;
+  }
+
+  // note: no response sent back
+  toPacket() {
+    const packet = new Packet(0, Buffer.allocUnsafe(9), 0, 9);
+    packet.offset = 4;
+    packet.writeInt8(CommandCodes.STMT_CLOSE);
+    packet.writeInt32(this.id);
+    return packet;
+  }
+}
+
+module.exports = CloseStatement;

backend/node_modules/mysql2/lib/packets/column_definition.js

@@ -0,0 +1,291 @@
+'use strict';
+
+const Packet = require('../packets/packet');
+const StringParser = require('../parsers/string');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+
+const fields = ['catalog', 'schema', 'table', 'orgTable', 'name', 'orgName'];
+
+// creating JS string is relatively expensive (compared to
+// reading few bytes from buffer) because all string properties
+// except for name are unlikely to be used we postpone
+// string conversion until property access
+//
+// TODO: watch for integration benchmarks (one with real network buffer)
+// there could be bad side effect as keeping reference to a buffer makes it
+// sit in the memory longer (usually until final .query() callback)
+// Latest v8 perform much better in regard to bufferer -> string conversion,
+// at some point of time this optimisation might become unnecessary
+// see https://github.com/sidorares/node-mysql2/pull/137
+//
+class ColumnDefinition {
+  constructor(packet, clientEncoding) {
+    this._buf = packet.buffer;
+    this._clientEncoding = clientEncoding;
+    this._catalogLength = packet.readLengthCodedNumber();
+    this._catalogStart = packet.offset;
+    packet.offset += this._catalogLength;
+    this._schemaLength = packet.readLengthCodedNumber();
+    this._schemaStart = packet.offset;
+    packet.offset += this._schemaLength;
+    this._tableLength = packet.readLengthCodedNumber();
+    this._tableStart = packet.offset;
+    packet.offset += this._tableLength;
+    this._orgTableLength = packet.readLengthCodedNumber();
+    this._orgTableStart = packet.offset;
+    packet.offset += this._orgTableLength;
+    // name is always used, don't make it lazy
+    const _nameLength = packet.readLengthCodedNumber();
+    const _nameStart = packet.offset;
+    packet.offset += _nameLength;
+    this._orgNameLength = packet.readLengthCodedNumber();
+    this._orgNameStart = packet.offset;
+    packet.offset += this._orgNameLength;
+    packet.skip(1); //  length of the following fields (always 0x0c)
+    this.characterSet = packet.readInt16();
+    this.encoding = CharsetToEncoding[this.characterSet];
+    this.name = StringParser.decode(
+      this._buf,
+      this.encoding === 'binary' ? this._clientEncoding : this.encoding,
+      _nameStart,
+      _nameStart + _nameLength
+    );
+    this.columnLength = packet.readInt32();
+    this.columnType = packet.readInt8();
+    this.type = this.columnType;
+    this.flags = packet.readInt16();
+    this.decimals = packet.readInt8();
+  }
+
+  inspect() {
+    return {
+      catalog: this.catalog,
+      schema: this.schema,
+      name: this.name,
+      orgName: this.orgName,
+      table: this.table,
+      orgTable: this.orgTable,
+      characterSet: this.characterSet,
+      encoding: this.encoding,
+      columnLength: this.columnLength,
+      type: this.columnType,
+      flags: this.flags,
+      decimals: this.decimals,
+    };
+  }
+
+  [Symbol.for('nodejs.util.inspect.custom')](depth, inspectOptions, inspect) {
+    const Types = require('../constants/types.js');
+    const typeNames = [];
+    for (const t in Types) {
+      typeNames[Types[t]] = t;
+    }
+    const fiedFlags = require('../constants/field_flags.js');
+    const flagNames = [];
+    // TODO: respect inspectOptions.showHidden
+    //const inspectFlags = inspectOptions.showHidden ? this.flags : this.flags & ~fiedFlags.PRI_KEY;
+    const inspectFlags = this.flags;
+    for (const f in fiedFlags) {
+      if (inspectFlags & fiedFlags[f]) {
+        if (f === 'PRI_KEY') {
+          flagNames.push('PRIMARY KEY');
+        } else if (f === 'NOT_NULL') {
+          flagNames.push('NOT NULL');
+        } else if (f === 'BINARY') {
+          // ignore flag for now
+        } else if (f === 'MULTIPLE_KEY') {
+          // not sure if that should be part of inspection.
+          // in the schema usually this is part of index definition
+          // example: UNIQUE KEY `my_uniq_id` (`id_box_elements`,`id_router`)
+          // note that only first column has MULTIPLE_KEY flag set in this case
+          // so there is no good way of knowing that this is part of index just
+          // by looking at indifidual field flags
+        } else if (f === 'NO_DEFAULT_VALUE') {
+          // almost the same as NOT_NULL?
+        } else if (f === 'BLOB') {
+          // included in the type
+        } else if (f === 'UNSIGNED') {
+          // this should be first after type
+        } else if (f === 'TIMESTAMP') {
+          // timestamp flag is redundant for inspection - already included in type
+        } else if (f === 'ON_UPDATE_NOW') {
+          flagNames.push('ON UPDATE CURRENT_TIMESTAMP');
+        } else {
+          flagNames.push(f);
+        }
+      }
+    }
+
+    if (depth > 1) {
+      return inspect({
+        ...this.inspect(),
+        typeName: typeNames[this.columnType],
+        flags: flagNames,
+      });
+    }
+
+    const isUnsigned = this.flags & fiedFlags.UNSIGNED;
+
+    let typeName = typeNames[this.columnType];
+    if (typeName === 'BLOB') {
+      // TODO: check for non-utf8mb4 encoding
+      if (this.columnLength === 4294967295) {
+        typeName = 'LONGTEXT';
+      } else if (this.columnLength === 67108860) {
+        typeName = 'MEDIUMTEXT';
+      } else if (this.columnLength === 262140) {
+        typeName = 'TEXT';
+      } else if (this.columnLength === 1020) {
+        // 255*4
+        typeName = 'TINYTEXT';
+      } else {
+        typeName = `BLOB(${this.columnLength})`;
+      }
+    } else if (typeName === 'VAR_STRING') {
+      // TODO: check for non-utf8mb4 encoding
+      typeName = `VARCHAR(${Math.ceil(this.columnLength / 4)})`;
+    } else if (typeName === 'TINY') {
+      if (
+        (this.columnLength === 3 && isUnsigned) ||
+        (this.columnLength === 4 && !isUnsigned)
+      ) {
+        typeName = 'TINYINT';
+      } else {
+        typeName = `TINYINT(${this.columnLength})`;
+      }
+    } else if (typeName === 'LONGLONG') {
+      if (this.columnLength === 20) {
+        typeName = 'BIGINT';
+      } else {
+        typeName = `BIGINT(${this.columnLength})`;
+      }
+    } else if (typeName === 'SHORT') {
+      if (isUnsigned && this.columnLength === 5) {
+        typeName = 'SMALLINT';
+      } else if (!isUnsigned && this.columnLength === 6) {
+        typeName = 'SMALLINT';
+      } else {
+        typeName = `SMALLINT(${this.columnLength})`;
+      }
+    } else if (typeName === 'LONG') {
+      if (isUnsigned && this.columnLength === 10) {
+        typeName = 'INT';
+      } else if (!isUnsigned && this.columnLength === 11) {
+        typeName = 'INT';
+      } else {
+        typeName = `INT(${this.columnLength})`;
+      }
+    } else if (typeName === 'INT24') {
+      if (isUnsigned && this.columnLength === 8) {
+        typeName = 'MEDIUMINT';
+      } else if (!isUnsigned && this.columnLength === 9) {
+        typeName = 'MEDIUMINT';
+      } else {
+        typeName = `MEDIUMINT(${this.columnLength})`;
+      }
+    } else if (typeName === 'DOUBLE') {
+      // DOUBLE without modifiers is reported as DOUBLE(22, 31)
+      if (this.columnLength === 22 && this.decimals === 31) {
+        typeName = 'DOUBLE';
+      } else {
+        typeName = `DOUBLE(${this.columnLength},${this.decimals})`;
+      }
+    } else if (typeName === 'FLOAT') {
+      // FLOAT without modifiers is reported as FLOAT(12, 31)
+      if (this.columnLength === 12 && this.decimals === 31) {
+        typeName = 'FLOAT';
+      } else {
+        typeName = `FLOAT(${this.columnLength},${this.decimals})`;
+      }
+    } else if (typeName === 'NEWDECIMAL') {
+      if (this.columnLength === 11 && this.decimals === 0) {
+        typeName = 'DECIMAL';
+      } else if (this.decimals === 0) {
+        // not sure why, but DECIMAL(13) is reported as DECIMAL(14, 0)
+        // and DECIMAL(13, 9) is reported as NEWDECIMAL(15, 9)
+        if (isUnsigned) {
+          typeName = `DECIMAL(${this.columnLength})`;
+        } else {
+          typeName = `DECIMAL(${this.columnLength - 1})`;
+        }
+      } else {
+        typeName = `DECIMAL(${this.columnLength - 2},${this.decimals})`;
+      }
+    } else {
+      typeName = `${typeNames[this.columnType]}(${this.columnLength})`;
+    }
+
+    if (isUnsigned) {
+      typeName += ' UNSIGNED';
+    }
+
+    // TODO respect colors option
+    return `\`${this.name}\` ${[typeName, ...flagNames].join(' ')}`;
+  }
+
+  static toPacket(column, sequenceId) {
+    let length = 17; // = 4 padding + 1 + 12 for the rest
+    fields.forEach((field) => {
+      length += Packet.lengthCodedStringLength(
+        column[field],
+        CharsetToEncoding[column.characterSet]
+      );
+    });
+    const buffer = Buffer.allocUnsafe(length);
+
+    const packet = new Packet(sequenceId, buffer, 0, length);
+    function writeField(name) {
+      packet.writeLengthCodedString(
+        column[name],
+        CharsetToEncoding[column.characterSet]
+      );
+    }
+    packet.offset = 4;
+    fields.forEach(writeField);
+    packet.writeInt8(0x0c);
+    packet.writeInt16(column.characterSet);
+    packet.writeInt32(column.columnLength);
+    packet.writeInt8(column.columnType);
+    packet.writeInt16(column.flags);
+    packet.writeInt8(column.decimals);
+    packet.writeInt16(0); // filler
+    return packet;
+  }
+
+  // node-mysql compatibility: alias "db" to "schema"
+  get db() {
+    return this.schema;
+  }
+}
+
+const addString = function (name) {
+  Object.defineProperty(ColumnDefinition.prototype, name, {
+    get: function () {
+      const start = this[`_${name}Start`];
+      const end = start + this[`_${name}Length`];
+      const val = StringParser.decode(
+        this._buf,
+        this.encoding === 'binary' ? this._clientEncoding : this.encoding,
+        start,
+        end
+      );
+
+      Object.defineProperty(this, name, {
+        value: val,
+        writable: false,
+        configurable: false,
+        enumerable: false,
+      });
+
+      return val;
+    },
+  });
+};
+
+addString('catalog');
+addString('schema');
+addString('table');
+addString('orgTable');
+addString('orgName');
+
+module.exports = ColumnDefinition;

backend/node_modules/mysql2/lib/packets/encode_parameter.js

@@ -0,0 +1,69 @@
+'use strict';
+
+const Types = require('../constants/types');
+const Packet = require('../packets/packet');
+
+function isJSON(value) {
+  return (
+    Array.isArray(value) ||
+    value.constructor === Object ||
+    (typeof value.toJSON === 'function' && !Buffer.isBuffer(value))
+  );
+}
+
+function toParameter(value, encoding, timezone) {
+  let type = Types.VAR_STRING;
+  let length;
+  let writer = function (value) {
+    // eslint-disable-next-line no-invalid-this
+    return Packet.prototype.writeLengthCodedString.call(this, value, encoding);
+  };
+  if (value !== null) {
+    switch (typeof value) {
+      case 'undefined':
+        throw new TypeError('Bind parameters must not contain undefined');
+
+      case 'number':
+        type = Types.DOUBLE;
+        length = 8;
+        writer = Packet.prototype.writeDouble;
+        break;
+
+      case 'boolean':
+        value = value | 0;
+        type = Types.TINY;
+        length = 1;
+        writer = Packet.prototype.writeInt8;
+        break;
+
+      case 'object':
+        if (Object.prototype.toString.call(value) === '[object Date]') {
+          type = Types.DATETIME;
+          length = 12;
+          writer = function (value) {
+            // eslint-disable-next-line no-invalid-this
+            return Packet.prototype.writeDate.call(this, value, timezone);
+          };
+        } else if (isJSON(value)) {
+          value = JSON.stringify(value);
+          type = Types.JSON;
+        } else if (Buffer.isBuffer(value)) {
+          length = Packet.lengthCodedNumberLength(value.length) + value.length;
+          writer = Packet.prototype.writeLengthCodedBuffer;
+        }
+        break;
+
+      default:
+        value = value.toString();
+    }
+  } else {
+    value = '';
+    type = Types.NULL;
+  }
+  if (!length) {
+    length = Packet.lengthCodedStringLength(value, encoding);
+  }
+  return { value, type, length, writer };
+}
+
+module.exports = { toParameter, isJSON };

backend/node_modules/mysql2/lib/packets/execute.js

@@ -0,0 +1,177 @@
+'use strict';
+
+const CursorType = require('../constants/cursor');
+const CommandCodes = require('../constants/commands');
+const ClientConstants = require('../constants/client');
+const Types = require('../constants/types');
+const Packet = require('../packets/packet');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+const { toParameter } = require('./encode_parameter.js');
+
+class Execute {
+  constructor(
+    id,
+    parameters,
+    charsetNumber,
+    timezone,
+    attributes,
+    clientFlags
+  ) {
+    this.id = id;
+    this.parameters = parameters;
+    this.encoding = CharsetToEncoding[charsetNumber];
+    this.timezone = timezone;
+    this.attributes = attributes;
+    this.clientFlags = clientFlags || 0;
+  }
+
+  static fromPacket(packet, encoding) {
+    const stmtId = packet.readInt32();
+    const flags = packet.readInt8();
+    const iterationCount = packet.readInt32();
+
+    let i = packet.offset;
+    while (i < packet.end - 1) {
+      if (
+        (packet.buffer[i + 1] === Types.VAR_STRING ||
+          packet.buffer[i + 1] === Types.NULL ||
+          packet.buffer[i + 1] === Types.DOUBLE ||
+          packet.buffer[i + 1] === Types.TINY ||
+          packet.buffer[i + 1] === Types.DATETIME ||
+          packet.buffer[i + 1] === Types.JSON) &&
+        packet.buffer[i] === 1 &&
+        packet.buffer[i + 2] === 0
+      ) {
+        break;
+      } else {
+        packet.readInt8();
+      }
+      i++;
+    }
+
+    const types = [];
+
+    for (let i = packet.offset + 1; i < packet.end - 1; i++) {
+      if (
+        (packet.buffer[i] === Types.VAR_STRING ||
+          packet.buffer[i] === Types.NULL ||
+          packet.buffer[i] === Types.DOUBLE ||
+          packet.buffer[i] === Types.TINY ||
+          packet.buffer[i] === Types.DATETIME ||
+          packet.buffer[i] === Types.JSON) &&
+        packet.buffer[i + 1] === 0
+      ) {
+        types.push(packet.buffer[i]);
+        packet.skip(2);
+      }
+    }
+
+    packet.skip(1);
+
+    const values = [];
+    for (let i = 0; i < types.length; i++) {
+      if (types[i] === Types.VAR_STRING) {
+        values.push(packet.readLengthCodedString(encoding));
+      } else if (types[i] === Types.DOUBLE) {
+        values.push(packet.readDouble());
+      } else if (types[i] === Types.TINY) {
+        values.push(packet.readInt8());
+      } else if (types[i] === Types.DATETIME) {
+        values.push(packet.readDateTime());
+      } else if (types[i] === Types.JSON) {
+        values.push(JSON.parse(packet.readLengthCodedString(encoding)));
+      }
+      if (types[i] === Types.NULL) {
+        values.push(null);
+      }
+    }
+
+    return { stmtId, flags, iterationCount, values };
+  }
+
+  _serializeToBuffer(buffer) {
+    const useQueryAttributes =
+      this.clientFlags & ClientConstants.CLIENT_QUERY_ATTRIBUTES;
+
+    const attrNames =
+      useQueryAttributes && this.attributes ? Object.keys(this.attributes) : [];
+    const numParams = this.parameters ? this.parameters.length : 0;
+    const numAttrs = attrNames.length;
+    const totalParams = numParams + numAttrs;
+
+    const packet = new Packet(0, buffer, 0, buffer.length);
+    packet.offset = 4;
+    packet.writeInt8(CommandCodes.STMT_EXECUTE);
+    packet.writeInt32(this.id);
+
+    let cursorFlags = CursorType.NO_CURSOR;
+    if (useQueryAttributes) {
+      cursorFlags |= CursorType.PARAMETER_COUNT_AVAILABLE;
+    }
+    packet.writeInt8(cursorFlags);
+    packet.writeInt32(1); // iteration-count, always 1
+
+    if (useQueryAttributes) {
+      packet.writeLengthCodedNumber(totalParams);
+    }
+
+    if (totalParams > 0) {
+      const bindParams =
+        numParams > 0
+          ? this.parameters.map((v) =>
+              toParameter(v, this.encoding, this.timezone)
+            )
+          : [];
+      const attrParams = attrNames.map((name) =>
+        toParameter(this.attributes[name], this.encoding, this.timezone)
+      );
+      const allParams = bindParams.concat(attrParams);
+
+      // null bitmap
+      let bitmap = 0;
+      let bitValue = 1;
+      allParams.forEach((parameter) => {
+        if (parameter.type === Types.NULL) {
+          bitmap += bitValue;
+        }
+        bitValue *= 2;
+        if (bitValue === 256) {
+          packet.writeInt8(bitmap);
+          bitmap = 0;
+          bitValue = 1;
+        }
+      });
+      if (bitValue !== 1) {
+        packet.writeInt8(bitmap);
+      }
+
+      packet.writeInt8(1); // new-params-bound-flag
+
+      // types (and names for attributes)
+      for (let i = 0; i < allParams.length; i++) {
+        packet.writeInt8(allParams[i].type);
+        packet.writeInt8(0); // unsigned flag
+        if (useQueryAttributes) {
+          const name = i < numParams ? '' : attrNames[i - numParams];
+          packet.writeLengthCodedString(name, this.encoding);
+        }
+      }
+
+      // values
+      allParams.forEach((parameter) => {
+        if (parameter.type !== Types.NULL) {
+          parameter.writer.call(packet, parameter.value);
+        }
+      });
+    }
+
+    return packet;
+  }
+
+  toPacket() {
+    const p = this._serializeToBuffer(Packet.MockBuffer());
+    return this._serializeToBuffer(Buffer.allocUnsafe(p.offset));
+  }
+}
+
+module.exports = Execute;

backend/node_modules/mysql2/lib/packets/handshake.js

@@ -0,0 +1,112 @@
+'use strict';
+
+const Packet = require('../packets/packet');
+const ClientConstants = require('../constants/client.js');
+
+// https://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::Handshake
+
+class Handshake {
+  constructor(args) {
+    this.protocolVersion = args.protocolVersion;
+    this.serverVersion = args.serverVersion;
+    this.capabilityFlags = args.capabilityFlags;
+    this.connectionId = args.connectionId;
+    this.authPluginData1 = args.authPluginData1;
+    this.authPluginData2 = args.authPluginData2;
+    this.characterSet = args.characterSet;
+    this.statusFlags = args.statusFlags;
+    this.authPluginName = args.authPluginName;
+  }
+
+  setScrambleData(cb) {
+    require('crypto').randomBytes(20, (err, data) => {
+      if (err) {
+        cb(err);
+        return;
+      }
+      this.authPluginData1 = data.slice(0, 8);
+      this.authPluginData2 = data.slice(8, 20);
+      cb();
+    });
+  }
+
+  toPacket(sequenceId) {
+    const length = 68 + Buffer.byteLength(this.serverVersion, 'utf8');
+    const buffer = Buffer.alloc(length + 4, 0); // zero fill, 10 bytes filler later needs to contain zeros
+    const packet = new Packet(sequenceId, buffer, 0, length + 4);
+    packet.offset = 4;
+    packet.writeInt8(this.protocolVersion);
+    packet.writeString(this.serverVersion, 'cesu8');
+    packet.writeInt8(0);
+    packet.writeInt32(this.connectionId);
+    packet.writeBuffer(this.authPluginData1);
+    packet.writeInt8(0);
+    const capabilityFlagsBuffer = Buffer.allocUnsafe(4);
+    capabilityFlagsBuffer.writeUInt32LE(this.capabilityFlags, 0);
+    packet.writeBuffer(capabilityFlagsBuffer.slice(0, 2));
+    packet.writeInt8(this.characterSet);
+    packet.writeInt16(this.statusFlags);
+    packet.writeBuffer(capabilityFlagsBuffer.slice(2, 4));
+    packet.writeInt8(21); // authPluginDataLength
+    packet.skip(10);
+    packet.writeBuffer(this.authPluginData2);
+    packet.writeInt8(0);
+    packet.writeString('mysql_native_password', 'latin1');
+    packet.writeInt8(0);
+    return packet;
+  }
+
+  static fromPacket(packet) {
+    const args = {};
+    args.protocolVersion = packet.readInt8();
+    args.serverVersion = packet.readNullTerminatedString('cesu8');
+    args.connectionId = packet.readInt32();
+    args.authPluginData1 = packet.readBuffer(8);
+    packet.skip(1);
+    const capabilityFlagsBuffer = Buffer.allocUnsafe(4);
+    capabilityFlagsBuffer[0] = packet.readInt8();
+    capabilityFlagsBuffer[1] = packet.readInt8();
+    if (packet.haveMoreData()) {
+      args.characterSet = packet.readInt8();
+      args.statusFlags = packet.readInt16();
+      // upper 2 bytes
+      capabilityFlagsBuffer[2] = packet.readInt8();
+      capabilityFlagsBuffer[3] = packet.readInt8();
+      args.capabilityFlags = capabilityFlagsBuffer.readUInt32LE(0);
+      if (args.capabilityFlags & ClientConstants.PLUGIN_AUTH) {
+        args.authPluginDataLength = packet.readInt8();
+      } else {
+        args.authPluginDataLength = 0;
+        packet.skip(1);
+      }
+      packet.skip(10);
+    } else {
+      args.capabilityFlags = capabilityFlagsBuffer.readUInt16LE(0);
+    }
+
+    const isSecureConnection =
+      args.capabilityFlags & ClientConstants.SECURE_CONNECTION;
+    if (isSecureConnection) {
+      const authPluginDataLength = args.authPluginDataLength;
+      if (authPluginDataLength === 0) {
+        // for Secure Password Authentication
+        args.authPluginDataLength = 20;
+        args.authPluginData2 = packet.readBuffer(12);
+        packet.skip(1);
+      } else {
+        // length > 0
+        // for Custom Auth Plugin (PLUGIN_AUTH)
+        const len = Math.max(13, authPluginDataLength - 8);
+        args.authPluginData2 = packet.readBuffer(len);
+      }
+    }
+
+    if (args.capabilityFlags & ClientConstants.PLUGIN_AUTH) {
+      args.authPluginName = packet.readNullTerminatedString('ascii');
+    }
+
+    return new Handshake(args);
+  }
+}
+
+module.exports = Handshake;

backend/node_modules/mysql2/lib/packets/handshake_response.js

@@ -0,0 +1,173 @@
+'use strict';
+
+const ClientConstants = require('../constants/client.js');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+const Packet = require('../packets/packet.js');
+
+const auth41 = require('../auth_41.js');
+
+class HandshakeResponse {
+  constructor(handshake) {
+    this.user = handshake.user || '';
+    this.database = handshake.database || '';
+    this.password = handshake.password || '';
+    this.passwordSha1 = handshake.passwordSha1;
+    this.authPluginData1 = handshake.authPluginData1;
+    this.authPluginData2 = handshake.authPluginData2;
+    this.compress = handshake.compress;
+    this.clientFlags = handshake.flags;
+
+    // Accept pre-calculated authToken and authPluginName from caller
+    // This allows the caller to optimize by using the server's preferred auth method
+    if (
+      handshake.authToken !== undefined &&
+      handshake.authPluginName !== undefined
+    ) {
+      // Validate types to fail fast with clear errors
+      if (!Buffer.isBuffer(handshake.authToken)) {
+        throw new TypeError(
+          'HandshakeResponse authToken must be a Buffer when provided'
+        );
+      }
+      if (typeof handshake.authPluginName !== 'string') {
+        throw new TypeError(
+          'HandshakeResponse authPluginName must be a string when provided'
+        );
+      }
+      this.authToken = handshake.authToken;
+      this.authPluginName = handshake.authPluginName;
+    } else {
+      // Fallback to legacy behavior: calculate mysql_native_password token
+      // TODO: pre-4.1 auth support
+      let authToken;
+      if (this.passwordSha1) {
+        authToken = auth41.calculateTokenFromPasswordSha(
+          this.passwordSha1,
+          this.authPluginData1,
+          this.authPluginData2
+        );
+      } else {
+        authToken = auth41.calculateToken(
+          this.password,
+          this.authPluginData1,
+          this.authPluginData2
+        );
+      }
+      this.authToken = authToken;
+      this.authPluginName = 'mysql_native_password';
+    }
+
+    this.charsetNumber = handshake.charsetNumber;
+    this.encoding = CharsetToEncoding[handshake.charsetNumber];
+    this.connectAttributes = handshake.connectAttributes;
+  }
+
+  serializeResponse(buffer) {
+    const isSet = (flag) => this.clientFlags & ClientConstants[flag];
+    const packet = new Packet(0, buffer, 0, buffer.length);
+    packet.offset = 4;
+    packet.writeInt32(this.clientFlags);
+    packet.writeInt32(0); // max packet size. todo: move to config
+    packet.writeInt8(this.charsetNumber);
+    packet.skip(23);
+    const encoding = this.encoding;
+    packet.writeNullTerminatedString(this.user, encoding);
+    let k;
+    if (isSet('PLUGIN_AUTH_LENENC_CLIENT_DATA')) {
+      packet.writeLengthCodedNumber(this.authToken.length);
+      packet.writeBuffer(this.authToken);
+    } else if (isSet('SECURE_CONNECTION')) {
+      packet.writeInt8(this.authToken.length);
+      packet.writeBuffer(this.authToken);
+    } else {
+      packet.writeBuffer(this.authToken);
+      packet.writeInt8(0);
+    }
+    if (isSet('CONNECT_WITH_DB')) {
+      packet.writeNullTerminatedString(this.database, encoding);
+    }
+    if (isSet('PLUGIN_AUTH')) {
+      // Use the auth plugin name specified by the caller (optimized for server's preference)
+      // or fall back to mysql_native_password for backward compatibility
+      packet.writeNullTerminatedString(
+        this.authPluginName || 'mysql_native_password',
+        'latin1'
+      );
+    }
+    if (isSet('CONNECT_ATTRS')) {
+      const connectAttributes = this.connectAttributes || {};
+      const attrNames = Object.keys(connectAttributes);
+      let keysLength = 0;
+      for (k = 0; k < attrNames.length; ++k) {
+        keysLength += Packet.lengthCodedStringLength(attrNames[k], encoding);
+        keysLength += Packet.lengthCodedStringLength(
+          connectAttributes[attrNames[k]],
+          encoding
+        );
+      }
+      packet.writeLengthCodedNumber(keysLength);
+      for (k = 0; k < attrNames.length; ++k) {
+        packet.writeLengthCodedString(attrNames[k], encoding);
+        packet.writeLengthCodedString(
+          connectAttributes[attrNames[k]],
+          encoding
+        );
+      }
+    }
+    return packet;
+  }
+
+  toPacket() {
+    if (typeof this.user !== 'string') {
+      throw new Error('"user" connection config property must be a string');
+    }
+    if (typeof this.database !== 'string') {
+      throw new Error('"database" connection config property must be a string');
+    }
+    // dry run: calculate resulting packet length
+    const p = this.serializeResponse(Packet.MockBuffer());
+    return this.serializeResponse(Buffer.alloc(p.offset));
+  }
+  static fromPacket(packet, serverFlags = 0xffffffff) {
+    const args = {};
+    args.clientFlags = packet.readInt32();
+    function isSet(flag) {
+      return args.clientFlags & serverFlags & ClientConstants[flag];
+    }
+    args.maxPacketSize = packet.readInt32();
+    args.charsetNumber = packet.readInt8();
+    const encoding = CharsetToEncoding[args.charsetNumber];
+    args.encoding = encoding;
+    packet.skip(23);
+    args.user = packet.readNullTerminatedString(encoding);
+    let authTokenLength;
+    if (isSet('PLUGIN_AUTH_LENENC_CLIENT_DATA')) {
+      authTokenLength = packet.readLengthCodedNumber(encoding);
+      args.authToken = packet.readBuffer(authTokenLength);
+    } else if (isSet('SECURE_CONNECTION')) {
+      authTokenLength = packet.readInt8();
+      args.authToken = packet.readBuffer(authTokenLength);
+    } else {
+      args.authToken = packet.readNullTerminatedString(encoding);
+    }
+    if (isSet('CONNECT_WITH_DB')) {
+      args.database = packet.readNullTerminatedString(encoding);
+    }
+    if (isSet('PLUGIN_AUTH')) {
+      args.authPluginName = packet.readNullTerminatedString(encoding);
+    }
+    if (isSet('CONNECT_ATTRS')) {
+      const keysLength = packet.readLengthCodedNumber(encoding);
+      const keysEnd = packet.offset + keysLength;
+      const attrs = {};
+      while (packet.offset < keysEnd) {
+        attrs[packet.readLengthCodedString(encoding)] =
+          packet.readLengthCodedString(encoding);
+      }
+      args.connectAttributes = attrs;
+    }
+    return args;
+  }
+}
+
+module.exports = HandshakeResponse;

backend/node_modules/mysql2/lib/packets/index.js

@@ -0,0 +1,154 @@
+// This file was modified by Oracle on June 1, 2021.
+// A utility method was introduced to generate an Error instance from a
+// binary server packet.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+// This file was modified by Oracle on September 21, 2021.
+// The new AuthNextFactor packet is now available.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+const process = require('process');
+
+const AuthNextFactor = require('./auth_next_factor');
+const AuthSwitchRequest = require('./auth_switch_request');
+const AuthSwitchRequestMoreData = require('./auth_switch_request_more_data');
+const AuthSwitchResponse = require('./auth_switch_response');
+const BinaryRow = require('./binary_row');
+const BinlogDump = require('./binlog_dump');
+const ChangeUser = require('./change_user');
+const CloseStatement = require('./close_statement');
+const ColumnDefinition = require('./column_definition');
+const Execute = require('./execute');
+const Handshake = require('./handshake');
+const HandshakeResponse = require('./handshake_response');
+const PrepareStatement = require('./prepare_statement');
+const PreparedStatementHeader = require('./prepared_statement_header');
+const Query = require('./query');
+const RegisterSlave = require('./register_slave');
+const ResetConnection = require('./reset_connection');
+const ResultSetHeader = require('./resultset_header');
+const SSLRequest = require('./ssl_request');
+const TextRow = require('./text_row');
+
+const ctorMap = {
+  AuthNextFactor,
+  AuthSwitchRequest,
+  AuthSwitchRequestMoreData,
+  AuthSwitchResponse,
+  BinaryRow,
+  BinlogDump,
+  ChangeUser,
+  CloseStatement,
+  ColumnDefinition,
+  Execute,
+  Handshake,
+  HandshakeResponse,
+  PrepareStatement,
+  PreparedStatementHeader,
+  Query,
+  RegisterSlave,
+  ResetConnection,
+  ResultSetHeader,
+  SSLRequest,
+  TextRow,
+};
+Object.entries(ctorMap).forEach(([name, ctor]) => {
+  module.exports[name] = ctor;
+  // monkey-patch it to include name if debug is on
+  if (process.env.NODE_DEBUG) {
+    if (ctor.prototype.toPacket) {
+      const old = ctor.prototype.toPacket;
+      ctor.prototype.toPacket = function () {
+        const p = old.call(this);
+        p._name = name;
+        return p;
+      };
+    }
+  }
+});
+
+// simple packets:
+const Packet = require('./packet');
+exports.Packet = Packet;
+
+class OK {
+  static toPacket(args, encoding) {
+    args = args || {};
+    const affectedRows = args.affectedRows || 0;
+    const insertId = args.insertId || 0;
+    const serverStatus = args.serverStatus || 0;
+    const warningCount = args.warningCount || 0;
+    const message = args.message || '';
+
+    let length = 9 + Packet.lengthCodedNumberLength(affectedRows);
+    length += Packet.lengthCodedNumberLength(insertId);
+
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeInt8(0);
+    packet.writeLengthCodedNumber(affectedRows);
+    packet.writeLengthCodedNumber(insertId);
+    packet.writeInt16(serverStatus);
+    packet.writeInt16(warningCount);
+    packet.writeString(message, encoding);
+    packet._name = 'OK';
+    return packet;
+  }
+}
+
+exports.OK = OK;
+
+// warnings, statusFlags
+class EOF {
+  static toPacket(warnings, statusFlags) {
+    if (typeof warnings === 'undefined') {
+      warnings = 0;
+    }
+    if (typeof statusFlags === 'undefined') {
+      statusFlags = 0;
+    }
+    const packet = new Packet(0, Buffer.allocUnsafe(9), 0, 9);
+    packet.offset = 4;
+    packet.writeInt8(0xfe);
+    packet.writeInt16(warnings);
+    packet.writeInt16(statusFlags);
+    packet._name = 'EOF';
+    return packet;
+  }
+}
+
+exports.EOF = EOF;
+
+class Error {
+  static toPacket(args, encoding) {
+    const length = 13 + Buffer.byteLength(args.message, 'utf8');
+    const packet = new Packet(0, Buffer.allocUnsafe(length), 0, length);
+    packet.offset = 4;
+    packet.writeInt8(0xff);
+    packet.writeInt16(args.code);
+    // TODO: sql state parameter
+    packet.writeString('#_____', encoding);
+    packet.writeString(args.message, encoding);
+    packet._name = 'Error';
+    return packet;
+  }
+
+  static fromPacket(packet) {
+    packet.readInt8(); // marker
+    const code = packet.readInt16();
+    packet.readString(1, 'ascii'); // sql state marker
+    // The SQL state of the ERR_Packet which is always 5 bytes long.
+    // https://dev.mysql.com/doc/dev/mysql-server/8.0.11/page_protocol_basic_dt_strings.html#sect_protocol_basic_dt_string_fix
+    packet.readString(5, 'ascii'); // sql state (ignore for now)
+    const message = packet.readNullTerminatedString('utf8');
+    const error = new Error();
+    error.message = message;
+    error.code = code;
+    return error;
+  }
+}
+
+exports.Error = Error;

backend/node_modules/mysql2/lib/packets/packet.js

@@ -0,0 +1,981 @@
+// This file was modified by Oracle on June 1, 2021.
+// A comment describing some changes in the strict default SQL mode regarding
+// non-standard dates was introduced.
+// Modifications copyright (c) 2021, Oracle and/or its affiliates.
+
+'use strict';
+
+const ErrorCodeToName = require('../constants/errors.js');
+const NativeBuffer = require('buffer').Buffer;
+const Long = require('long');
+const StringParser = require('../parsers/string.js');
+const Types = require('../constants/types.js');
+const INVALID_DATE = new Date(NaN);
+
+// this is nearly duplicate of previous function so generated code is not slower
+// due to "if (dateStrings)" branching
+const pad = '000000000000';
+function leftPad(num, value) {
+  const s = value.toString();
+  // if we don't need to pad
+  if (s.length >= num) {
+    return s;
+  }
+  return (pad + s).slice(-num);
+}
+
+// The whole reason parse* function below exist
+// is because String creation is relatively expensive (at least with V8), and if we have
+// a buffer with "12345" content ideally we would like to bypass intermediate
+// "12345" string creation and directly build 12345 number out of
+// <Buffer 31 32 33 34 35> data.
+// In my benchmarks the difference is ~25M 8-digit numbers per second vs
+// 4.5 M using Number(packet.readLengthCodedString())
+// not used when size is close to max precision as series of *10 accumulate error
+// and approximate result mihgt be diffreent from (approximate as well) Number(bigNumStringValue))
+// In the futire node version if speed difference is smaller parse* functions might be removed
+// don't consider them as Packet public API
+
+const minus = '-'.charCodeAt(0);
+const plus = '+'.charCodeAt(0);
+
+// TODO: handle E notation
+const dot = '.'.charCodeAt(0);
+const exponent = 'e'.charCodeAt(0);
+const exponentCapital = 'E'.charCodeAt(0);
+
+class Packet {
+  constructor(id, buffer, start, end) {
+    // hot path, enable checks when testing only
+    // if (!Buffer.isBuffer(buffer) || typeof start == 'undefined' || typeof end == 'undefined')
+    //  throw new Error('invalid packet');
+    this.sequenceId = id;
+    this.numPackets = 1;
+    this.buffer = buffer;
+    this.start = start;
+    this.offset = start + 4;
+    this.end = end;
+  }
+
+  // ==============================
+  // readers
+  // ==============================
+  reset() {
+    this.offset = this.start + 4;
+  }
+
+  length() {
+    return this.end - this.start;
+  }
+
+  slice() {
+    return this.buffer.slice(this.start, this.end);
+  }
+
+  dump() {
+    console.log(
+      [this.buffer.asciiSlice(this.start, this.end)],
+      this.buffer.slice(this.start, this.end),
+      this.length(),
+      this.sequenceId
+    );
+  }
+
+  haveMoreData() {
+    return this.end > this.offset;
+  }
+
+  skip(num) {
+    this.offset += num;
+  }
+
+  readInt8() {
+    return this.buffer[this.offset++];
+  }
+
+  readInt16() {
+    this.offset += 2;
+    return this.buffer.readUInt16LE(this.offset - 2);
+  }
+
+  readInt24() {
+    return this.readInt16() + (this.readInt8() << 16);
+  }
+
+  readInt32() {
+    this.offset += 4;
+    return this.buffer.readUInt32LE(this.offset - 4);
+  }
+
+  readSInt8() {
+    return this.buffer.readInt8(this.offset++);
+  }
+
+  readSInt16() {
+    this.offset += 2;
+    return this.buffer.readInt16LE(this.offset - 2);
+  }
+
+  readSInt32() {
+    this.offset += 4;
+    return this.buffer.readInt32LE(this.offset - 4);
+  }
+
+  readInt64JSNumber() {
+    const word0 = this.readInt32();
+    const word1 = this.readInt32();
+    const l = new Long(word0, word1, true);
+    return l.toNumber();
+  }
+
+  readSInt64JSNumber() {
+    const word0 = this.readInt32();
+    const word1 = this.readInt32();
+    if (!(word1 & 0x80000000)) {
+      return word0 + 0x100000000 * word1;
+    }
+    const l = new Long(word0, word1, false);
+    return l.toNumber();
+  }
+
+  readInt64String() {
+    const word0 = this.readInt32();
+    const word1 = this.readInt32();
+    const res = new Long(word0, word1, true);
+    return res.toString();
+  }
+
+  readSInt64String() {
+    const word0 = this.readInt32();
+    const word1 = this.readInt32();
+    const res = new Long(word0, word1, false);
+    return res.toString();
+  }
+
+  readInt64() {
+    const word0 = this.readInt32();
+    const word1 = this.readInt32();
+    const res = new Long(word0, word1, true);
+    const resNumber = res.toNumber();
+    return Number.isSafeInteger(resNumber) ? resNumber : res.toString();
+  }
+
+  readSInt64() {
+    const word0 = this.readInt32();
+    const word1 = this.readInt32();
+    const res = new Long(word0, word1, false);
+    const resNumber = res.toNumber();
+    return Number.isSafeInteger(resNumber) ? resNumber : res.toString();
+  }
+
+  isEOF() {
+    return this.buffer[this.offset] === 0xfe && this.length() < 13;
+  }
+
+  eofStatusFlags() {
+    return this.buffer.readInt16LE(this.offset + 3);
+  }
+
+  eofWarningCount() {
+    return this.buffer.readInt16LE(this.offset + 1);
+  }
+
+  readLengthCodedNumber(bigNumberStrings, signed) {
+    const byte1 = this.buffer[this.offset++];
+    if (byte1 < 251) {
+      return byte1;
+    }
+    return this.readLengthCodedNumberExt(byte1, bigNumberStrings, signed);
+  }
+
+  readLengthCodedNumberSigned(bigNumberStrings) {
+    return this.readLengthCodedNumber(bigNumberStrings, true);
+  }
+
+  readLengthCodedNumberExt(tag, bigNumberStrings, signed) {
+    let word0, word1;
+    let res;
+    if (tag === 0xfb) {
+      return null;
+    }
+    if (tag === 0xfc) {
+      return this.readInt8() + (this.readInt8() << 8);
+    }
+    if (tag === 0xfd) {
+      return this.readInt8() + (this.readInt8() << 8) + (this.readInt8() << 16);
+    }
+    if (tag === 0xfe) {
+      // TODO: check version
+      // Up to MySQL 3.22, 0xfe was followed by a 4-byte integer.
+      word0 = this.readInt32();
+      word1 = this.readInt32();
+      if (word1 === 0) {
+        return word0; // don't convert to float if possible
+      }
+      if (word1 < 2097152) {
+        // max exact float point int, 2^52 / 2^32
+        return word1 * 0x100000000 + word0;
+      }
+      res = new Long(word0, word1, !signed); // Long need unsigned
+      const resNumber = res.toNumber();
+      const resString = res.toString();
+      if (bigNumberStrings || !Number.isSafeInteger(resNumber)) {
+        return resString;
+      }
+      return resNumber;
+    }
+
+    console.trace();
+    throw new Error(`Should not reach here: ${tag}`);
+  }
+
+  readFloat() {
+    const res = this.buffer.readFloatLE(this.offset);
+    this.offset += 4;
+    return res;
+  }
+
+  readDouble() {
+    const res = this.buffer.readDoubleLE(this.offset);
+    this.offset += 8;
+    return res;
+  }
+
+  readBuffer(len) {
+    if (typeof len === 'undefined') {
+      len = this.end - this.offset;
+    }
+    this.offset += len;
+    return this.buffer.slice(this.offset - len, this.offset);
+  }
+
+  // DATE, DATETIME and TIMESTAMP
+  readDateTime(timezone) {
+    if (!timezone || timezone === 'Z' || timezone === 'local') {
+      const length = this.readInt8();
+      if (length === 0xfb) {
+        return null;
+      }
+      let y = 0;
+      let m = 0;
+      let d = 0;
+      let H = 0;
+      let M = 0;
+      let S = 0;
+      let ms = 0;
+      if (length > 3) {
+        y = this.readInt16();
+        m = this.readInt8();
+        d = this.readInt8();
+      }
+      if (length > 6) {
+        H = this.readInt8();
+        M = this.readInt8();
+        S = this.readInt8();
+      }
+      if (length > 10) {
+        ms = this.readInt32() / 1000;
+      }
+      // NO_ZERO_DATE mode and NO_ZERO_IN_DATE mode are part of the strict
+      // default SQL mode used by MySQL 8.0. This means that non-standard
+      // dates like '0000-00-00' become NULL. For older versions and other
+      // possible MySQL flavours we still need to account for the
+      // non-standard behaviour.
+      if (y + m + d + H + M + S + ms === 0) {
+        return INVALID_DATE;
+      }
+      if (timezone === 'Z') {
+        return new Date(Date.UTC(y, m - 1, d, H, M, S, ms));
+      }
+      return new Date(y, m - 1, d, H, M, S, ms);
+    }
+    let str = this.readDateTimeString(6, 'T', null);
+    if (!str) {
+      return INVALID_DATE;
+    }
+    if (str.length === 10) {
+      str += 'T00:00:00';
+    }
+    return new Date(str + timezone);
+  }
+
+  readDateTimeString(decimals, timeSep, columnType) {
+    const length = this.readInt8();
+    let y = 0;
+    let m = 0;
+    let d = 0;
+    let H = 0;
+    let M = 0;
+    let S = 0;
+    let ms = 0;
+    let str;
+    if (length > 3) {
+      y = this.readInt16();
+      m = this.readInt8();
+      d = this.readInt8();
+      str = [leftPad(4, y), leftPad(2, m), leftPad(2, d)].join('-');
+    }
+    if (length > 6) {
+      H = this.readInt8();
+      M = this.readInt8();
+      S = this.readInt8();
+      str += `${timeSep || ' '}${[
+        leftPad(2, H),
+        leftPad(2, M),
+        leftPad(2, S),
+      ].join(':')}`;
+    } else if (
+      columnType === Types.DATETIME ||
+      columnType === Types.TIMESTAMP
+    ) {
+      str += ' 00:00:00';
+    }
+    if (length > 10) {
+      ms = this.readInt32();
+      str += '.';
+      if (decimals) {
+        ms = leftPad(6, ms);
+        if (ms.length > decimals) {
+          ms = ms.substring(0, decimals); // rounding is done at the MySQL side, only 0 are here
+        }
+      }
+      str += ms;
+    }
+    return str;
+  }
+
+  // TIME - value as a string, Can be negative
+  readTimeString(convertTtoMs) {
+    const length = this.readInt8();
+    if (length === 0) {
+      return '00:00:00';
+    }
+    const sign = this.readInt8() ? -1 : 1; // 'isNegative' flag byte
+    let d = 0;
+    let H = 0;
+    let M = 0;
+    let S = 0;
+    let ms = 0;
+    if (length > 6) {
+      d = this.readInt32();
+      H = this.readInt8();
+      M = this.readInt8();
+      S = this.readInt8();
+    }
+    if (length > 10) {
+      ms = this.readInt32();
+    }
+    if (convertTtoMs) {
+      H += d * 24;
+      M += H * 60;
+      S += M * 60;
+      ms += S * 1000;
+      ms *= sign;
+      return ms;
+    }
+    // Format follows mySQL TIME format ([-][h]hh:mm:ss[.u[u[u[u[u[u]]]]]])
+    // For positive times below 24 hours, this makes it equal to ISO 8601 times
+    return (
+      (sign === -1 ? '-' : '') +
+      [leftPad(2, d * 24 + H), leftPad(2, M), leftPad(2, S)].join(':') +
+      (ms ? `.${ms}`.replace(/0+$/, '') : '')
+    );
+  }
+
+  readLengthCodedString(encoding) {
+    const len = this.readLengthCodedNumber();
+    // TODO: check manually first byte here to avoid polymorphic return type?
+    if (len === null) {
+      return null;
+    }
+    this.offset += len;
+    // TODO: Use characterSetCode to get proper encoding
+    // https://github.com/sidorares/node-mysql2/pull/374
+    return StringParser.decode(
+      this.buffer,
+      encoding,
+      this.offset - len,
+      this.offset
+    );
+  }
+
+  readLengthCodedBuffer() {
+    const len = this.readLengthCodedNumber();
+    if (len === null) {
+      return null;
+    }
+    return this.readBuffer(len);
+  }
+
+  readNullTerminatedString(encoding) {
+    const start = this.offset;
+    let end = this.offset;
+    while (end < this.end && this.buffer[end] !== 0x00) {
+      end = end + 1;
+    }
+    this.offset = end + 1;
+    return StringParser.decode(this.buffer, encoding, start, end);
+  }
+
+  // TODO reuse?
+  readString(len, encoding) {
+    if (typeof len === 'string' && typeof encoding === 'undefined') {
+      encoding = len;
+      len = undefined;
+    }
+    if (typeof len === 'undefined') {
+      len = this.end - this.offset;
+    }
+    this.offset += len;
+    return StringParser.decode(
+      this.buffer,
+      encoding,
+      this.offset - len,
+      this.offset
+    );
+  }
+
+  parseInt(len, supportBigNumbers) {
+    if (len === null) {
+      return null;
+    }
+    if (len >= 14 && !supportBigNumbers) {
+      const s = this.buffer.toString('ascii', this.offset, this.offset + len);
+      this.offset += len;
+      return Number(s);
+    }
+    let result = 0;
+    const start = this.offset;
+    const end = this.offset + len;
+    let sign = 1;
+    if (len === 0) {
+      return 0; // TODO: assert? exception?
+    }
+    if (this.buffer[this.offset] === minus) {
+      this.offset++;
+      sign = -1;
+    }
+    // max precise int is 9007199254740992
+    let str;
+    const numDigits = end - this.offset;
+    if (supportBigNumbers) {
+      if (numDigits >= 15) {
+        str = this.readString(end - this.offset, 'binary');
+        result = parseInt(str, 10);
+        if (Number.isSafeInteger(sign * result)) {
+          return sign * result;
+        }
+        return sign === -1 ? `-${str}` : str;
+      }
+      if (numDigits > 16) {
+        str = this.readString(end - this.offset);
+        return sign === -1 ? `-${str}` : str;
+      }
+    }
+    if (this.buffer[this.offset] === plus) {
+      this.offset++; // just ignore
+    }
+    while (this.offset < end) {
+      result *= 10;
+      result += this.buffer[this.offset] - 48;
+      this.offset++;
+    }
+    const num = result * sign;
+    if (!supportBigNumbers) {
+      return num;
+    }
+    if (Number.isSafeInteger(num)) {
+      return num;
+    }
+    return this.buffer.toString('ascii', start, end);
+  }
+
+  // note that if value of inputNumberAsString is bigger than MAX_SAFE_INTEGER
+  // ( or smaller than MIN_SAFE_INTEGER ) the parseIntNoBigCheck result might be
+  // different from what you would get from Number(inputNumberAsString)
+  // String(parseIntNoBigCheck) <> String(Number(inputNumberAsString)) <> inputNumberAsString
+  parseIntNoBigCheck(len) {
+    if (len === null) {
+      return null;
+    }
+    let result = 0;
+    const end = this.offset + len;
+    let sign = 1;
+    if (len === 0) {
+      return 0; // TODO: assert? exception?
+    }
+    if (this.buffer[this.offset] === minus) {
+      this.offset++;
+      sign = -1;
+    }
+    if (this.buffer[this.offset] === plus) {
+      this.offset++; // just ignore
+    }
+    while (this.offset < end) {
+      result *= 10;
+      result += this.buffer[this.offset] - 48;
+      this.offset++;
+    }
+    return result * sign;
+  }
+
+  // adapted from https://github.com/mysqljs/mysql/blob/dc9c152a87ec51a1f647447268917243d2eab1fd/lib/protocol/Parser.js
+  parseGeometryValue() {
+    const buffer = this.readLengthCodedBuffer();
+    let offset = 4;
+    if (buffer === null || !buffer.length) {
+      return null;
+    }
+    const bufferLength = buffer.length;
+    function parseGeometry() {
+      let x, y, i, j, numPoints, numRings, num, line;
+      let result = null;
+      if (offset + 5 > bufferLength) {
+        return null;
+      }
+      const byteOrder = buffer.readUInt8(offset);
+      offset += 1;
+      const wkbType = byteOrder
+        ? buffer.readUInt32LE(offset)
+        : buffer.readUInt32BE(offset);
+      offset += 4;
+      switch (wkbType) {
+        case 1: // WKBPoint
+          if (offset + 16 > bufferLength) {
+            return null;
+          }
+          x = byteOrder
+            ? buffer.readDoubleLE(offset)
+            : buffer.readDoubleBE(offset);
+          offset += 8;
+          y = byteOrder
+            ? buffer.readDoubleLE(offset)
+            : buffer.readDoubleBE(offset);
+          offset += 8;
+          result = { x: x, y: y };
+          break;
+        case 2: // WKBLineString
+          if (offset + 4 > bufferLength) {
+            return null;
+          }
+          numPoints = byteOrder
+            ? buffer.readUInt32LE(offset)
+            : buffer.readUInt32BE(offset);
+          offset += 4;
+          if (numPoints > (bufferLength - offset) / 16) {
+            return null;
+          }
+          result = [];
+          for (i = numPoints; i > 0; i--) {
+            if (offset + 16 > bufferLength) {
+              break;
+            }
+            x = byteOrder
+              ? buffer.readDoubleLE(offset)
+              : buffer.readDoubleBE(offset);
+            offset += 8;
+            y = byteOrder
+              ? buffer.readDoubleLE(offset)
+              : buffer.readDoubleBE(offset);
+            offset += 8;
+            result.push({ x: x, y: y });
+          }
+          break;
+        case 3: // WKBPolygon
+          if (offset + 4 > bufferLength) {
+            return null;
+          }
+          numRings = byteOrder
+            ? buffer.readUInt32LE(offset)
+            : buffer.readUInt32BE(offset);
+          offset += 4;
+          if (numRings > (bufferLength - offset) / 4) {
+            return null;
+          }
+          result = [];
+          for (i = numRings; i > 0; i--) {
+            if (offset + 4 > bufferLength) {
+              break;
+            }
+            numPoints = byteOrder
+              ? buffer.readUInt32LE(offset)
+              : buffer.readUInt32BE(offset);
+            offset += 4;
+            line = [];
+            for (j = numPoints; j > 0; j--) {
+              if (offset + 16 > bufferLength) {
+                break;
+              }
+              x = byteOrder
+                ? buffer.readDoubleLE(offset)
+                : buffer.readDoubleBE(offset);
+              offset += 8;
+              y = byteOrder
+                ? buffer.readDoubleLE(offset)
+                : buffer.readDoubleBE(offset);
+              offset += 8;
+              line.push({ x: x, y: y });
+            }
+            result.push(line);
+          }
+          break;
+        case 4: // WKBMultiPoint
+        case 5: // WKBMultiLineString
+        case 6: // WKBMultiPolygon
+        case 7: // WKBGeometryCollection
+          if (offset + 4 > bufferLength) {
+            return null;
+          }
+          num = byteOrder
+            ? buffer.readUInt32LE(offset)
+            : buffer.readUInt32BE(offset);
+          offset += 4;
+          if (num > (bufferLength - offset) / 9) {
+            return null;
+          }
+          result = [];
+          for (i = num; i > 0; i--) {
+            result.push(parseGeometry());
+          }
+          break;
+      }
+      return result;
+    }
+    return parseGeometry();
+  }
+
+  parseVector() {
+    const bufLen = this.readLengthCodedNumber();
+    const vectorEnd = this.offset + bufLen;
+    const result = [];
+    while (this.offset < vectorEnd && this.offset < this.end) {
+      result.push(this.readFloat());
+    }
+    return result;
+  }
+
+  parseDate(timezone) {
+    const strLen = this.readLengthCodedNumber();
+    if (strLen === null) {
+      return null;
+    }
+    if (strLen !== 10) {
+      // we expect only YYYY-MM-DD here.
+      // if for some reason it's not the case return invalid date
+      return new Date(NaN);
+    }
+    const y = this.parseInt(4);
+    this.offset++; // -
+    const m = this.parseInt(2);
+    this.offset++; // -
+    const d = this.parseInt(2);
+    if (!timezone || timezone === 'local') {
+      return new Date(y, m - 1, d);
+    }
+    if (timezone === 'Z') {
+      return new Date(Date.UTC(y, m - 1, d));
+    }
+    return new Date(
+      `${leftPad(4, y)}-${leftPad(2, m)}-${leftPad(2, d)}T00:00:00${timezone}`
+    );
+  }
+
+  parseDateTime(timezone) {
+    const str = this.readLengthCodedString('binary');
+    if (str === null) {
+      return null;
+    }
+    if (!timezone || timezone === 'local') {
+      return new Date(str);
+    }
+    return new Date(`${str}${timezone}`);
+  }
+
+  parseFloat(len) {
+    if (len === null) {
+      return null;
+    }
+    if (len === 0) {
+      return 0; // TODO: assert? exception?
+    }
+
+    // For numbers with many digits (>17), use built-in parseFloat to avoid
+    // precision loss from accumulated rounding errors in repeated *10 operations.
+    // This fixes issues #2928 (MAX_VALUE doubles) and #3690 (DECIMAL(36,18))
+    // where very large numbers or numbers with many fractional digits lose precision.
+    // The threshold of 17 is based on IEEE 754 double precision (~15-17 significant digits).
+    // Testing shows minimal performance impact as most real-world numbers are shorter.
+    if (len > 17) {
+      const str = this.buffer.toString('utf8', this.offset, this.offset + len);
+      this.offset += len;
+      return Number.parseFloat(str);
+    }
+
+    let result = 0;
+    const end = this.offset + len;
+    let factor = 1;
+    let pastDot = false;
+    let charCode = 0;
+    if (this.buffer[this.offset] === minus) {
+      this.offset++;
+      factor = -1;
+    }
+    if (this.buffer[this.offset] === plus) {
+      this.offset++; // just ignore
+    }
+    while (this.offset < end) {
+      charCode = this.buffer[this.offset];
+      if (charCode === dot) {
+        pastDot = true;
+        this.offset++;
+      } else if (charCode === exponent || charCode === exponentCapital) {
+        // Scientific notation detected - bail out to parseFloat for exact match.
+        // Manual calculation with Math.pow(10, exp) cannot match parseFloat()
+        // exactly for most non-zero exponents due to accumulated rounding errors.
+        const start = end - len;
+        const str = this.buffer.toString('utf8', start, end);
+        this.offset = end;
+        return Number.parseFloat(str);
+      } else {
+        result *= 10;
+        result += this.buffer[this.offset] - 48;
+        this.offset++;
+        if (pastDot) {
+          factor = factor * 10;
+        }
+      }
+    }
+    return result / factor;
+  }
+
+  parseLengthCodedIntNoBigCheck() {
+    return this.parseIntNoBigCheck(this.readLengthCodedNumber());
+  }
+
+  parseLengthCodedInt(supportBigNumbers) {
+    return this.parseInt(this.readLengthCodedNumber(), supportBigNumbers);
+  }
+
+  parseLengthCodedIntString() {
+    return this.readLengthCodedString('binary');
+  }
+
+  parseLengthCodedFloat() {
+    return this.parseFloat(this.readLengthCodedNumber());
+  }
+
+  peekByte() {
+    return this.buffer[this.offset];
+  }
+
+  // OxFE is often used as "Alt" flag - not ok, not error.
+  // For example, it's first byte of AuthSwitchRequest
+  isAlt() {
+    return this.peekByte() === 0xfe;
+  }
+
+  isError() {
+    return this.peekByte() === 0xff;
+  }
+
+  asError(encoding) {
+    this.reset();
+    this.readInt8(); // fieldCount
+    const errorCode = this.readInt16();
+    let sqlState = '';
+    if (this.buffer[this.offset] === 0x23) {
+      this.skip(1);
+      sqlState = this.readBuffer(5).toString();
+    }
+    const message = this.readString(undefined, encoding);
+    const err = new Error(message);
+    err.code = ErrorCodeToName[errorCode];
+    err.errno = errorCode;
+    err.sqlState = sqlState;
+    err.sqlMessage = message;
+    return err;
+  }
+
+  writeInt32(n) {
+    this.buffer.writeUInt32LE(n, this.offset);
+    this.offset += 4;
+  }
+
+  writeInt24(n) {
+    this.writeInt8(n & 0xff);
+    this.writeInt16(n >> 8);
+  }
+
+  writeInt16(n) {
+    this.buffer.writeUInt16LE(n, this.offset);
+    this.offset += 2;
+  }
+
+  writeInt8(n) {
+    this.buffer.writeUInt8(n, this.offset);
+    this.offset++;
+  }
+
+  writeDouble(n) {
+    this.buffer.writeDoubleLE(n, this.offset);
+    this.offset += 8;
+  }
+
+  writeBuffer(b) {
+    b.copy(this.buffer, this.offset);
+    this.offset += b.length;
+  }
+
+  writeNull() {
+    this.buffer[this.offset] = 0xfb;
+    this.offset++;
+  }
+
+  // TODO: refactor following three?
+  writeNullTerminatedString(s, encoding) {
+    const buf = StringParser.encode(s, encoding);
+    this.buffer.length && buf.copy(this.buffer, this.offset);
+    this.offset += buf.length;
+    this.writeInt8(0);
+  }
+
+  writeString(s, encoding) {
+    if (s === null) {
+      this.writeInt8(0xfb);
+      return;
+    }
+    if (s.length === 0) {
+      return;
+    }
+    // const bytes = Buffer.byteLength(s, 'utf8');
+    // this.buffer.write(s, this.offset, bytes, 'utf8');
+    // this.offset += bytes;
+    const buf = StringParser.encode(s, encoding);
+    this.buffer.length && buf.copy(this.buffer, this.offset);
+    this.offset += buf.length;
+  }
+
+  writeLengthCodedString(s, encoding) {
+    const buf = StringParser.encode(s, encoding);
+    this.writeLengthCodedNumber(buf.length);
+    this.buffer.length && buf.copy(this.buffer, this.offset);
+    this.offset += buf.length;
+  }
+
+  writeLengthCodedBuffer(b) {
+    this.writeLengthCodedNumber(b.length);
+    b.copy(this.buffer, this.offset);
+    this.offset += b.length;
+  }
+
+  writeLengthCodedNumber(n) {
+    if (n < 0xfb) {
+      return this.writeInt8(n);
+    }
+    if (n < 0xffff) {
+      this.writeInt8(0xfc);
+      return this.writeInt16(n);
+    }
+    if (n < 0xffffff) {
+      this.writeInt8(0xfd);
+      return this.writeInt24(n);
+    }
+    if (n === null) {
+      return this.writeInt8(0xfb);
+    }
+    this.writeInt8(0xfe);
+    this.buffer.writeUInt32LE(n >>> 0, this.offset);
+    this.offset += 4;
+    this.buffer.writeUInt32LE(Math.floor(n / 0x100000000), this.offset);
+    this.offset += 4;
+    return this.offset;
+  }
+
+  writeDate(d, timezone) {
+    this.buffer.writeUInt8(11, this.offset);
+    if (!timezone || timezone === 'local') {
+      this.buffer.writeUInt16LE(d.getFullYear(), this.offset + 1);
+      this.buffer.writeUInt8(d.getMonth() + 1, this.offset + 3);
+      this.buffer.writeUInt8(d.getDate(), this.offset + 4);
+      this.buffer.writeUInt8(d.getHours(), this.offset + 5);
+      this.buffer.writeUInt8(d.getMinutes(), this.offset + 6);
+      this.buffer.writeUInt8(d.getSeconds(), this.offset + 7);
+      this.buffer.writeUInt32LE(d.getMilliseconds() * 1000, this.offset + 8);
+    } else {
+      if (timezone !== 'Z') {
+        const offset =
+          (timezone[0] === '-' ? -1 : 1) *
+          (parseInt(timezone.substring(1, 3), 10) * 60 +
+            parseInt(timezone.substring(4), 10));
+        if (offset !== 0) {
+          d = new Date(d.getTime() + 60000 * offset);
+        }
+      }
+      this.buffer.writeUInt16LE(d.getUTCFullYear(), this.offset + 1);
+      this.buffer.writeUInt8(d.getUTCMonth() + 1, this.offset + 3);
+      this.buffer.writeUInt8(d.getUTCDate(), this.offset + 4);
+      this.buffer.writeUInt8(d.getUTCHours(), this.offset + 5);
+      this.buffer.writeUInt8(d.getUTCMinutes(), this.offset + 6);
+      this.buffer.writeUInt8(d.getUTCSeconds(), this.offset + 7);
+      this.buffer.writeUInt32LE(d.getUTCMilliseconds() * 1000, this.offset + 8);
+    }
+    this.offset += 12;
+  }
+
+  writeHeader(sequenceId) {
+    const offset = this.offset;
+    this.offset = 0;
+    this.writeInt24(this.buffer.length - 4);
+    this.writeInt8(sequenceId);
+    this.offset = offset;
+  }
+
+  clone() {
+    return new Packet(this.sequenceId, this.buffer, this.start, this.end);
+  }
+
+  type() {
+    if (this.isEOF()) {
+      return 'EOF';
+    }
+    if (this.isError()) {
+      return 'Error';
+    }
+    if (this.buffer[this.offset] === 0) {
+      return 'maybeOK'; // could be other packet types as well
+    }
+    return '';
+  }
+
+  static lengthCodedNumberLength(n) {
+    if (n < 0xfb) {
+      return 1;
+    }
+    if (n < 0xffff) {
+      return 3;
+    }
+    if (n < 0xffffff) {
+      return 5;
+    }
+    return 9;
+  }
+
+  static lengthCodedStringLength(str, encoding) {
+    const buf = StringParser.encode(str, encoding);
+    const slen = buf.length;
+    return Packet.lengthCodedNumberLength(slen) + slen;
+  }
+
+  static MockBuffer() {
+    const noop = function () {};
+    const res = Buffer.alloc(0);
+    for (const op in NativeBuffer.prototype) {
+      if (typeof res[op] === 'function') {
+        res[op] = noop;
+      }
+    }
+    return res;
+  }
+}
+
+module.exports = Packet;

backend/node_modules/mysql2/lib/packets/prepare_statement.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const Packet = require('../packets/packet');
+const CommandCodes = require('../constants/commands');
+const StringParser = require('../parsers/string.js');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+
+class PrepareStatement {
+  constructor(sql, charsetNumber) {
+    this.query = sql;
+    this.charsetNumber = charsetNumber;
+    this.encoding = CharsetToEncoding[charsetNumber];
+  }
+
+  toPacket() {
+    const buf = StringParser.encode(this.query, this.encoding);
+    const length = 5 + buf.length;
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeInt8(CommandCodes.STMT_PREPARE);
+    packet.writeBuffer(buf);
+    return packet;
+  }
+}
+
+module.exports = PrepareStatement;

backend/node_modules/mysql2/lib/packets/prepared_statement_header.js

@@ -0,0 +1,16 @@
+'use strict';
+
+class PreparedStatementHeader {
+  constructor(packet) {
+    packet.skip(1); // should be 0
+    this.id = packet.readInt32();
+    this.fieldCount = packet.readInt16();
+    this.parameterCount = packet.readInt16();
+    packet.skip(1); // should be 0
+    this.warningCount = packet.readInt16();
+  }
+}
+
+// TODO: toPacket
+
+module.exports = PreparedStatementHeader;

backend/node_modules/mysql2/lib/packets/query.js

@@ -0,0 +1,102 @@
+'use strict';
+
+const Packet = require('../packets/packet.js');
+const CommandCode = require('../constants/commands.js');
+const StringParser = require('../parsers/string.js');
+const CharsetToEncoding = require('../constants/charset_encodings.js');
+const ClientConstants = require('../constants/client.js');
+const Types = require('../constants/types.js');
+const { toParameter } = require('./encode_parameter.js');
+
+class Query {
+  constructor(sql, charsetNumber, attributes, clientFlags) {
+    this.query = sql;
+    this.charsetNumber = charsetNumber;
+    this.encoding = CharsetToEncoding[charsetNumber];
+    this.attributes = attributes;
+    this.clientFlags = clientFlags || 0;
+  }
+
+  serializeToBuffer(buffer) {
+    const useQueryAttributes =
+      this.clientFlags & ClientConstants.CLIENT_QUERY_ATTRIBUTES;
+    const sqlBuf = StringParser.encode(this.query, this.encoding);
+    const packet = new Packet(0, buffer, 0, buffer.length);
+    packet.offset = 4;
+    packet.writeInt8(CommandCode.QUERY);
+
+    if (useQueryAttributes) {
+      const attrs = this.attributes;
+      const names = attrs ? Object.keys(attrs) : [];
+      const paramCount = names.length;
+
+      packet.writeLengthCodedNumber(paramCount);
+      packet.writeLengthCodedNumber(1); // parameter_set_count, always 1
+
+      if (paramCount > 0) {
+        const parameters = names.map((name) =>
+          toParameter(attrs[name], this.encoding, 'local')
+        );
+
+        // null bitmap
+        let bitmap = 0;
+        let bitValue = 1;
+        parameters.forEach((parameter) => {
+          if (parameter.type === Types.NULL) {
+            bitmap += bitValue;
+          }
+          bitValue *= 2;
+          if (bitValue === 256) {
+            packet.writeInt8(bitmap);
+            bitmap = 0;
+            bitValue = 1;
+          }
+        });
+        if (bitValue !== 1) {
+          packet.writeInt8(bitmap);
+        }
+
+        packet.writeInt8(1); // new_params_bind_flag
+
+        // types and names
+        for (let i = 0; i < paramCount; i++) {
+          packet.writeInt8(parameters[i].type);
+          packet.writeInt8(0); // unsigned flag
+          packet.writeLengthCodedString(names[i], this.encoding);
+        }
+
+        // values
+        parameters.forEach((parameter) => {
+          if (parameter.type !== Types.NULL) {
+            parameter.writer.call(packet, parameter.value);
+          }
+        });
+      }
+    }
+
+    packet.writeBuffer(sqlBuf);
+    return packet;
+  }
+
+  toPacket() {
+    const useQueryAttributes =
+      this.clientFlags & ClientConstants.CLIENT_QUERY_ATTRIBUTES;
+
+    if (!useQueryAttributes) {
+      const buf = StringParser.encode(this.query, this.encoding);
+      const length = 5 + buf.length;
+      const buffer = Buffer.allocUnsafe(length);
+      const packet = new Packet(0, buffer, 0, length);
+      packet.offset = 4;
+      packet.writeInt8(CommandCode.QUERY);
+      packet.writeBuffer(buf);
+      return packet;
+    }
+
+    // dry run to calculate required buffer length
+    const p = this.serializeToBuffer(Packet.MockBuffer());
+    return this.serializeToBuffer(Buffer.allocUnsafe(p.offset));
+  }
+}
+
+module.exports = Query;

backend/node_modules/mysql2/lib/packets/register_slave.js

@@ -0,0 +1,46 @@
+'use strict';
+
+// http://dev.mysql.com/doc/internals/en/com-register-slave.html
+// note that documentation is incorrect, for example command code is actually 0x15 but documented as 0x14
+
+const Packet = require('../packets/packet');
+const CommandCodes = require('../constants/commands');
+
+class RegisterSlave {
+  constructor(opts) {
+    this.serverId = opts.serverId || 0;
+    this.slaveHostname = opts.slaveHostname || '';
+    this.slaveUser = opts.slaveUser || '';
+    this.slavePassword = opts.slavePassword || '';
+    this.slavePort = opts.slavePort || 0;
+    this.replicationRank = opts.replicationRank || 0;
+    this.masterId = opts.masterId || 0;
+  }
+
+  toPacket() {
+    const length =
+      15 + // TODO: should be ascii?
+      Buffer.byteLength(this.slaveHostname, 'utf8') +
+      Buffer.byteLength(this.slaveUser, 'utf8') +
+      Buffer.byteLength(this.slavePassword, 'utf8') +
+      3 +
+      4;
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeInt8(CommandCodes.REGISTER_SLAVE);
+    packet.writeInt32(this.serverId);
+    packet.writeInt8(Buffer.byteLength(this.slaveHostname, 'utf8'));
+    packet.writeString(this.slaveHostname);
+    packet.writeInt8(Buffer.byteLength(this.slaveUser, 'utf8'));
+    packet.writeString(this.slaveUser);
+    packet.writeInt8(Buffer.byteLength(this.slavePassword, 'utf8'));
+    packet.writeString(this.slavePassword);
+    packet.writeInt16(this.slavePort);
+    packet.writeInt32(this.replicationRank);
+    packet.writeInt32(this.masterId);
+    return packet;
+  }
+}
+
+module.exports = RegisterSlave;

backend/node_modules/mysql2/lib/packets/reset_connection.js

@@ -0,0 +1,17 @@
+'use strict';
+
+const Packet = require('../packets/packet');
+const CommandCodes = require('../constants/commands');
+
+class ResetConnection {
+  constructor() {}
+
+  toPacket() {
+    const packet = new Packet(0, Buffer.alloc(5), 0, 5);
+    packet.offset = 4;
+    packet.writeInt8(CommandCodes.RESET_CONNECTION);
+    return packet;
+  }
+}
+
+module.exports = ResetConnection;

backend/node_modules/mysql2/lib/packets/resultset_header.js

@@ -0,0 +1,124 @@
+'use strict';
+
+// TODO: rename to OK packet
+// https://dev.mysql.com/doc/internals/en/packet-OK_Packet.html
+
+const Packet = require('./packet.js');
+const ClientConstants = require('../constants/client.js');
+const ServerSatusFlags = require('../constants/server_status.js');
+
+const EncodingToCharset = require('../constants/encoding_charset.js');
+const sessionInfoTypes = require('../constants/session_track.js');
+
+class ResultSetHeader {
+  constructor(packet, connection) {
+    const bigNumberStrings = connection.config.bigNumberStrings;
+    const encoding = connection.serverEncoding;
+    const flags = connection._handshakePacket.capabilityFlags;
+    const isSet = function (flag) {
+      return flags & ClientConstants[flag];
+    };
+    if (packet.buffer[packet.offset] !== 0) {
+      this.fieldCount = packet.readLengthCodedNumber();
+      if (this.fieldCount === null) {
+        this.infileName = packet.readString(undefined, encoding);
+      }
+      return;
+    }
+    this.fieldCount = packet.readInt8(); // skip OK byte
+    this.affectedRows = packet.readLengthCodedNumber(bigNumberStrings);
+    this.insertId = packet.readLengthCodedNumberSigned(bigNumberStrings);
+    this.info = '';
+    if (isSet('PROTOCOL_41')) {
+      this.serverStatus = packet.readInt16();
+      this.warningStatus = packet.readInt16();
+    } else if (isSet('TRANSACTIONS')) {
+      this.serverStatus = packet.readInt16();
+    }
+    let stateChanges = null;
+    if (isSet('SESSION_TRACK') && packet.offset < packet.end) {
+      this.info = packet.readLengthCodedString(encoding);
+
+      if (this.serverStatus & ServerSatusFlags.SERVER_SESSION_STATE_CHANGED) {
+        // session change info record - see
+        // https://dev.mysql.com/doc/internals/en/packet-OK_Packet.html#cs-sect-packet-ok-sessioninfo
+        let len =
+          packet.offset < packet.end ? packet.readLengthCodedNumber() : 0;
+        const end = packet.offset + len;
+        let type, key, stateEnd;
+        if (len > 0) {
+          stateChanges = {
+            systemVariables: {},
+            schema: null,
+            gtids: [],
+            trackStateChange: null,
+          };
+        }
+        while (packet.offset < end) {
+          type = packet.readInt8();
+          len = packet.readLengthCodedNumber();
+          stateEnd = packet.offset + len;
+          if (type === sessionInfoTypes.SYSTEM_VARIABLES) {
+            key = packet.readLengthCodedString(encoding);
+            const val = packet.readLengthCodedString(encoding);
+            stateChanges.systemVariables[key] = val;
+            if (key === 'character_set_client') {
+              const charsetNumber = EncodingToCharset[val];
+              // TODO - better api for driver users to handle unknown encodings?
+              // maybe custom coverter in the config?
+              // For now just ignore character_set_client command if there is
+              // no known mapping from reported encoding to a charset code
+              if (typeof charsetNumber !== 'undefined') {
+                connection.config.charsetNumber = charsetNumber;
+              }
+            }
+          } else if (type === sessionInfoTypes.SCHEMA) {
+            key = packet.readLengthCodedString(encoding);
+            stateChanges.schema = key;
+          } else if (type === sessionInfoTypes.STATE_CHANGE) {
+            stateChanges.trackStateChange =
+              packet.readLengthCodedString(encoding);
+          } else if (type === sessionInfoTypes.STATE_GTIDS) {
+            // TODO: find if the first length coded string means anything. Usually comes as empty
+            // eslint-disable-next-line no-unused-vars
+            const _unknownString = packet.readLengthCodedString(encoding);
+            const gtid = packet.readLengthCodedString(encoding);
+            stateChanges.gtids = gtid.split(',');
+          } else {
+            // unsupported session track type. For now just ignore
+          }
+          packet.offset = stateEnd;
+        }
+      }
+    } else {
+      this.info = packet.readString(undefined, encoding);
+    }
+    if (stateChanges) {
+      this.stateChanges = stateChanges;
+    }
+    const m = this.info.match(/\schanged:\s*(\d+)/i);
+    if (m !== null) {
+      this.changedRows = parseInt(m[1], 10);
+    } else {
+      this.changedRows = 0;
+    }
+  }
+
+  // TODO: should be consistent instance member, but it's just easier here to have just function
+  static toPacket(fieldCount, insertId) {
+    let length = 4 + Packet.lengthCodedNumberLength(fieldCount);
+    if (typeof insertId !== 'undefined') {
+      length += Packet.lengthCodedNumberLength(insertId);
+    }
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    packet.offset = 4;
+    packet.writeLengthCodedNumber(fieldCount);
+    if (typeof insertId !== 'undefined') {
+      packet.writeLengthCodedNumber(insertId);
+    }
+    return packet;
+  }
+}
+
+module.exports = ResultSetHeader;

backend/node_modules/mysql2/lib/packets/ssl_request.js

@@ -0,0 +1,25 @@
+'use strict';
+
+const ClientConstants = require('../constants/client');
+const Packet = require('../packets/packet');
+
+class SSLRequest {
+  constructor(flags, charset) {
+    this.clientFlags = flags | ClientConstants.SSL;
+    this.charset = charset;
+  }
+
+  toPacket() {
+    const length = 36;
+    const buffer = Buffer.allocUnsafe(length);
+    const packet = new Packet(0, buffer, 0, length);
+    buffer.fill(0);
+    packet.offset = 4;
+    packet.writeInt32(this.clientFlags);
+    packet.writeInt32(0); // max packet size. todo: move to config
+    packet.writeInt8(this.charset);
+    return packet;
+  }
+}
+
+module.exports = SSLRequest;

backend/node_modules/mysql2/lib/packets/text_row.js

@@ -0,0 +1,47 @@
+'use strict';
+
+const Packet = require('../packets/packet');
+
+class TextRow {
+  constructor(columns) {
+    this.columns = columns || [];
+  }
+
+  static fromPacket(packet) {
+    // packet.reset(); // set offset to starting point?
+    const columns = [];
+    while (packet.haveMoreData()) {
+      columns.push(packet.readLengthCodedString());
+    }
+    return new TextRow(columns);
+  }
+
+  static toPacket(columns, encoding) {
+    const sequenceId = 0; // TODO remove, this is calculated now in connecton
+    let length = 0;
+    columns.forEach((val) => {
+      if (val === null || typeof val === 'undefined') {
+        ++length;
+        return;
+      }
+      length += Packet.lengthCodedStringLength(val.toString(10), encoding);
+    });
+    const buffer = Buffer.allocUnsafe(length + 4);
+    const packet = new Packet(sequenceId, buffer, 0, length + 4);
+    packet.offset = 4;
+    columns.forEach((val) => {
+      if (val === null) {
+        packet.writeNull();
+        return;
+      }
+      if (typeof val === 'undefined') {
+        packet.writeInt8(0);
+        return;
+      }
+      packet.writeLengthCodedString(val.toString(10), encoding);
+    });
+    return packet;
+  }
+}
+
+module.exports = TextRow;

backend/node_modules/mysql2/lib/parsers/binary_parser.js

@@ -0,0 +1,235 @@
+'use strict';
+
+const FieldFlags = require('../constants/field_flags.js');
+const Charsets = require('../constants/charsets.js');
+const Types = require('../constants/types.js');
+const helpers = require('../helpers');
+const genFunc = require('generate-function');
+const parserCache = require('./parser_cache.js');
+const typeNames = [];
+for (const t in Types) {
+  typeNames[Types[t]] = t;
+}
+
+function readCodeFor(field, config, options, fieldNum) {
+  const supportBigNumbers = Boolean(
+    options.supportBigNumbers || config.supportBigNumbers
+  );
+  const bigNumberStrings = Boolean(
+    options.bigNumberStrings || config.bigNumberStrings
+  );
+  const timezone = options.timezone || config.timezone;
+  const dateStrings = options.dateStrings || config.dateStrings;
+  const unsigned = field.flags & FieldFlags.UNSIGNED;
+  switch (field.columnType) {
+    case Types.TINY:
+      return unsigned ? 'packet.readInt8();' : 'packet.readSInt8();';
+    case Types.SHORT:
+      return unsigned ? 'packet.readInt16();' : 'packet.readSInt16();';
+    case Types.LONG:
+    case Types.INT24: // in binary protocol int24 is encoded in 4 bytes int32
+      return unsigned ? 'packet.readInt32();' : 'packet.readSInt32();';
+    case Types.YEAR:
+      return 'packet.readInt16()';
+    case Types.FLOAT:
+      return 'packet.readFloat();';
+    case Types.DOUBLE:
+      return 'packet.readDouble();';
+    case Types.NULL:
+      return 'null;';
+    case Types.DATE:
+    case Types.DATETIME:
+    case Types.TIMESTAMP:
+    case Types.NEWDATE:
+      if (helpers.typeMatch(field.columnType, dateStrings, Types)) {
+        return `packet.readDateTimeString(${parseInt(field.decimals, 10)}, ${null}, ${field.columnType});`;
+      }
+      return `packet.readDateTime(${helpers.srcEscape(timezone)});`;
+    case Types.TIME:
+      return 'packet.readTimeString()';
+    case Types.DECIMAL:
+    case Types.NEWDECIMAL:
+      if (config.decimalNumbers) {
+        return 'packet.parseLengthCodedFloat();';
+      }
+      return 'packet.readLengthCodedString("ascii");';
+    case Types.GEOMETRY:
+      return 'packet.parseGeometryValue();';
+    case Types.VECTOR:
+      return 'packet.parseVector()';
+    case Types.JSON:
+      // Since for JSON columns mysql always returns charset 63 (BINARY),
+      // we have to handle it according to JSON specs and use "utf8",
+      // see https://github.com/sidorares/node-mysql2/issues/409
+      return config.jsonStrings
+        ? 'packet.readLengthCodedString("utf8")'
+        : 'JSON.parse(packet.readLengthCodedString("utf8"));';
+    case Types.LONGLONG:
+      if (!supportBigNumbers) {
+        return unsigned
+          ? 'packet.readInt64JSNumber();'
+          : 'packet.readSInt64JSNumber();';
+      }
+      if (bigNumberStrings) {
+        return unsigned
+          ? 'packet.readInt64String();'
+          : 'packet.readSInt64String();';
+      }
+      return unsigned ? 'packet.readInt64();' : 'packet.readSInt64();';
+
+    default:
+      if (field.characterSet === Charsets.BINARY) {
+        return 'packet.readLengthCodedBuffer();';
+      }
+      return `packet.readLengthCodedString(fields[${fieldNum}].encoding)`;
+  }
+}
+
+function compile(fields, options, config) {
+  const parserFn = genFunc();
+  const nullBitmapLength = Math.floor((fields.length + 7 + 2) / 8);
+
+  function wrap(field, packet) {
+    return {
+      type: typeNames[field.columnType],
+      length: field.columnLength,
+      db: field.schema,
+      table: field.table,
+      name: field.name,
+      string: function (encoding = field.encoding) {
+        if (field.columnType === Types.JSON && encoding === field.encoding) {
+          // Since for JSON columns mysql always returns charset 63 (BINARY),
+          // we have to handle it according to JSON specs and use "utf8",
+          // see https://github.com/sidorares/node-mysql2/issues/1661
+          console.warn(
+            `typeCast: JSON column "${field.name}" is interpreted as BINARY by default, recommended to manually set utf8 encoding: \`field.string("utf8")\``
+          );
+        }
+
+        if (
+          [Types.DATETIME, Types.NEWDATE, Types.TIMESTAMP, Types.DATE].includes(
+            field.columnType
+          )
+        ) {
+          return packet.readDateTimeString(
+            parseInt(field.decimals, 10),
+            ' ',
+            field.columnType
+          );
+        }
+
+        if (field.columnType === Types.TINY) {
+          const unsigned = field.flags & FieldFlags.UNSIGNED;
+
+          return String(unsigned ? packet.readInt8() : packet.readSInt8());
+        }
+
+        if (field.columnType === Types.TIME) {
+          return packet.readTimeString();
+        }
+
+        return packet.readLengthCodedString(encoding);
+      },
+      buffer: function () {
+        return packet.readLengthCodedBuffer();
+      },
+      geometry: function () {
+        return packet.parseGeometryValue();
+      },
+    };
+  }
+
+  parserFn('(function(){');
+  parserFn('return class BinaryRow {');
+  parserFn('constructor() {');
+  parserFn('}');
+
+  parserFn('next(packet, fields, options) {');
+  if (options.rowsAsArray) {
+    parserFn(`const result = new Array(${fields.length});`);
+  } else {
+    parserFn('const result = {};');
+  }
+
+  // Global typeCast
+  if (
+    typeof config.typeCast === 'function' &&
+    typeof options.typeCast !== 'function'
+  ) {
+    options.typeCast = config.typeCast;
+  }
+
+  parserFn('packet.readInt8();'); // status byte
+  for (let i = 0; i < nullBitmapLength; ++i) {
+    parserFn(`const nullBitmaskByte${i} = packet.readInt8();`);
+  }
+
+  let lvalue = '';
+  let currentFieldNullBit = 4;
+  let nullByteIndex = 0;
+  let fieldName = '';
+  let tableName = '';
+
+  for (let i = 0; i < fields.length; i++) {
+    fieldName = helpers.fieldEscape(fields[i].name);
+    // parserFn(`// ${fieldName}: ${typeNames[fields[i].columnType]}`);
+
+    if (typeof options.nestTables === 'string') {
+      lvalue = `result[${helpers.fieldEscape(fields[i].table + options.nestTables + fields[i].name)}]`;
+    } else if (options.nestTables === true) {
+      tableName = helpers.fieldEscape(fields[i].table);
+
+      parserFn(`if (!result[${tableName}]) result[${tableName}] = {};`);
+      lvalue = `result[${tableName}][${fieldName}]`;
+    } else if (options.rowsAsArray) {
+      lvalue = `result[${i.toString(10)}]`;
+    } else {
+      lvalue = `result[${fieldName}]`;
+    }
+
+    parserFn(`if (nullBitmaskByte${nullByteIndex} & ${currentFieldNullBit}) `);
+    parserFn(`${lvalue} = null;`);
+    parserFn('else {');
+
+    if (options.typeCast === false) {
+      parserFn(`${lvalue} = packet.readLengthCodedBuffer();`);
+    } else {
+      const fieldWrapperVar = `fieldWrapper${i}`;
+      parserFn(`const ${fieldWrapperVar} = wrap(fields[${i}], packet);`);
+      const readCode = readCodeFor(fields[i], config, options, i);
+
+      if (typeof options.typeCast === 'function') {
+        parserFn(
+          `${lvalue} = options.typeCast(${fieldWrapperVar}, function() { return ${readCode} });`
+        );
+      } else {
+        parserFn(`${lvalue} = ${readCode};`);
+      }
+    }
+    parserFn('}');
+
+    currentFieldNullBit *= 2;
+    if (currentFieldNullBit === 0x100) {
+      currentFieldNullBit = 1;
+      nullByteIndex++;
+    }
+  }
+
+  parserFn('return result;');
+  parserFn('}');
+  parserFn('};')('})()');
+
+  if (config.debug) {
+    helpers.printDebugWithCode(
+      'Compiled binary protocol row parser',
+      parserFn.toString()
+    );
+  }
+  return parserFn.toFunction({ wrap });
+}
+
+function getBinaryParser(fields, options, config) {
+  return parserCache.getParser('binary', fields, options, config, compile);
+}
+
+module.exports = getBinaryParser;

backend/node_modules/mysql2/lib/parsers/parser_cache.js

@@ -0,0 +1,68 @@
+'use strict';
+
+const { createLRU } = require('lru.min');
+
+const parserCache = createLRU({
+  max: 15000,
+});
+
+function keyFromFields(type, fields, options, config) {
+  const res = [
+    type,
+    typeof options.nestTables,
+    options.nestTables,
+    Boolean(options.rowsAsArray),
+    Boolean(options.supportBigNumbers || config.supportBigNumbers),
+    Boolean(options.bigNumberStrings || config.bigNumberStrings),
+    typeof options.typeCast === 'boolean'
+      ? options.typeCast
+      : typeof options.typeCast,
+    options.timezone || config.timezone,
+    Boolean(options.decimalNumbers),
+    options.dateStrings,
+  ];
+
+  for (let i = 0; i < fields.length; ++i) {
+    const field = fields[i];
+
+    res.push([
+      field.name,
+      field.columnType,
+      field.length,
+      field.schema,
+      field.table,
+      field.flags,
+      field.characterSet,
+    ]);
+  }
+
+  return JSON.stringify(res, null, 0);
+}
+
+function getParser(type, fields, options, config, compiler) {
+  const key = keyFromFields(type, fields, options, config);
+  let parser = parserCache.get(key);
+
+  if (parser) {
+    return parser;
+  }
+
+  parser = compiler(fields, options, config);
+  parserCache.set(key, parser);
+  return parser;
+}
+
+function setMaxCache(max) {
+  parserCache.resize(max);
+}
+
+function clearCache() {
+  parserCache.clear();
+}
+
+module.exports = {
+  getParser: getParser,
+  setMaxCache: setMaxCache,
+  clearCache: clearCache,
+  _keyFromFields: keyFromFields,
+};

backend/node_modules/mysql2/lib/parsers/static_binary_parser.js

@@ -0,0 +1,213 @@
+'use strict';
+
+const FieldFlags = require('../constants/field_flags.js');
+const Charsets = require('../constants/charsets.js');
+const Types = require('../constants/types.js');
+const helpers = require('../helpers');
+
+const typeNames = [];
+for (const t in Types) {
+  typeNames[Types[t]] = t;
+}
+
+function getBinaryParser(fields, _options, config) {
+  function readCode(field, config, options, fieldNum, packet) {
+    const supportBigNumbers = Boolean(
+      options.supportBigNumbers || config.supportBigNumbers
+    );
+    const bigNumberStrings = Boolean(
+      options.bigNumberStrings || config.bigNumberStrings
+    );
+    const timezone = options.timezone || config.timezone;
+    const dateStrings = options.dateStrings || config.dateStrings;
+    const unsigned = field.flags & FieldFlags.UNSIGNED;
+
+    switch (field.columnType) {
+      case Types.TINY:
+        return unsigned ? packet.readInt8() : packet.readSInt8();
+      case Types.SHORT:
+        return unsigned ? packet.readInt16() : packet.readSInt16();
+      case Types.LONG:
+      case Types.INT24: // in binary protocol int24 is encoded in 4 bytes int32
+        return unsigned ? packet.readInt32() : packet.readSInt32();
+      case Types.YEAR:
+        return packet.readInt16();
+      case Types.FLOAT:
+        return packet.readFloat();
+      case Types.DOUBLE:
+        return packet.readDouble();
+      case Types.NULL:
+        return null;
+      case Types.DATE:
+      case Types.DATETIME:
+      case Types.TIMESTAMP:
+      case Types.NEWDATE:
+        return helpers.typeMatch(field.columnType, dateStrings, Types)
+          ? packet.readDateTimeString(
+              parseInt(field.decimals, 10),
+              null,
+              field.columnType
+            )
+          : packet.readDateTime(timezone);
+      case Types.TIME:
+        return packet.readTimeString();
+      case Types.DECIMAL:
+      case Types.NEWDECIMAL:
+        return config.decimalNumbers
+          ? packet.parseLengthCodedFloat()
+          : packet.readLengthCodedString('ascii');
+      case Types.GEOMETRY:
+        return packet.parseGeometryValue();
+      case Types.VECTOR:
+        return packet.parseVector();
+      case Types.JSON:
+        // Since for JSON columns mysql always returns charset 63 (BINARY),
+        // we have to handle it according to JSON specs and use "utf8",
+        // see https://github.com/sidorares/node-mysql2/issues/409
+        return config.jsonStrings
+          ? packet.readLengthCodedString('utf8')
+          : JSON.parse(packet.readLengthCodedString('utf8'));
+      case Types.LONGLONG:
+        if (!supportBigNumbers)
+          return unsigned
+            ? packet.readInt64JSNumber()
+            : packet.readSInt64JSNumber();
+        return bigNumberStrings
+          ? unsigned
+            ? packet.readInt64String()
+            : packet.readSInt64String()
+          : unsigned
+            ? packet.readInt64()
+            : packet.readSInt64();
+      default:
+        return field.characterSet === Charsets.BINARY
+          ? packet.readLengthCodedBuffer()
+          : packet.readLengthCodedString(fields[fieldNum].encoding);
+    }
+  }
+
+  return class BinaryRow {
+    constructor() {}
+
+    next(packet, fields, options) {
+      packet.readInt8(); // status byte
+
+      const nullBitmapLength = Math.floor((fields.length + 7 + 2) / 8);
+      const nullBitmaskBytes = new Array(nullBitmapLength);
+
+      for (let i = 0; i < nullBitmapLength; i++) {
+        nullBitmaskBytes[i] = packet.readInt8();
+      }
+
+      const result = options.rowsAsArray ? new Array(fields.length) : {};
+      let currentFieldNullBit = 4;
+      let nullByteIndex = 0;
+
+      for (let i = 0; i < fields.length; i++) {
+        const field = fields[i];
+        const typeCast =
+          options.typeCast !== undefined ? options.typeCast : config.typeCast;
+
+        let value;
+        if (nullBitmaskBytes[nullByteIndex] & currentFieldNullBit) {
+          value = null;
+        } else if (options.typeCast === false) {
+          value = packet.readLengthCodedBuffer();
+        } else {
+          const next = () => readCode(field, config, options, i, packet);
+          value =
+            typeof typeCast === 'function'
+              ? typeCast(
+                  {
+                    type: typeNames[field.columnType],
+                    length: field.columnLength,
+                    db: field.schema,
+                    table: field.table,
+                    name: field.name,
+                    string: function (encoding = field.encoding) {
+                      if (
+                        field.columnType === Types.JSON &&
+                        encoding === field.encoding
+                      ) {
+                        // Since for JSON columns mysql always returns charset 63 (BINARY),
+                        // we have to handle it according to JSON specs and use "utf8",
+                        // see https://github.com/sidorares/node-mysql2/issues/1661
+                        console.warn(
+                          `typeCast: JSON column "${field.name}" is interpreted as BINARY by default, recommended to manually set utf8 encoding: \`field.string("utf8")\``
+                        );
+                      }
+
+                      if (
+                        [
+                          Types.DATETIME,
+                          Types.NEWDATE,
+                          Types.TIMESTAMP,
+                          Types.DATE,
+                        ].includes(field.columnType)
+                      ) {
+                        return packet.readDateTimeString(
+                          parseInt(field.decimals, 10),
+                          ' ',
+                          field.columnType
+                        );
+                      }
+
+                      if (field.columnType === Types.TINY) {
+                        const unsigned = field.flags & FieldFlags.UNSIGNED;
+
+                        return String(
+                          unsigned ? packet.readInt8() : packet.readSInt8()
+                        );
+                      }
+
+                      if (field.columnType === Types.TIME) {
+                        return packet.readTimeString();
+                      }
+
+                      return packet.readLengthCodedString(encoding);
+                    },
+                    buffer: function () {
+                      return packet.readLengthCodedBuffer();
+                    },
+                    geometry: function () {
+                      return packet.parseGeometryValue();
+                    },
+                  },
+                  next
+                )
+              : next();
+        }
+
+        if (options.rowsAsArray) {
+          result[i] = value;
+        } else if (typeof options.nestTables === 'string') {
+          const key = helpers.fieldEscape(
+            field.table + options.nestTables + field.name,
+            false
+          );
+          result[key] = value;
+        } else if (options.nestTables === true) {
+          const tableName = helpers.fieldEscape(field.table, false);
+          if (!result[tableName]) {
+            result[tableName] = {};
+          }
+          const fieldName = helpers.fieldEscape(field.name, false);
+          result[tableName][fieldName] = value;
+        } else {
+          const key = helpers.fieldEscape(field.name, false);
+          result[key] = value;
+        }
+
+        currentFieldNullBit *= 2;
+        if (currentFieldNullBit === 0x100) {
+          currentFieldNullBit = 1;
+          nullByteIndex++;
+        }
+      }
+
+      return result;
+    }
+  };
+}
+
+module.exports = getBinaryParser;

backend/node_modules/mysql2/lib/parsers/static_text_parser.js

@@ -0,0 +1,152 @@
+'use strict';
+
+const Types = require('../constants/types.js');
+const Charsets = require('../constants/charsets.js');
+const helpers = require('../helpers');
+
+const typeNames = [];
+for (const t in Types) {
+  typeNames[Types[t]] = t;
+}
+
+function readField({ packet, type, charset, encoding, config, options }) {
+  const supportBigNumbers = Boolean(
+    options.supportBigNumbers || config.supportBigNumbers
+  );
+  const bigNumberStrings = Boolean(
+    options.bigNumberStrings || config.bigNumberStrings
+  );
+  const timezone = options.timezone || config.timezone;
+  const dateStrings = options.dateStrings || config.dateStrings;
+
+  switch (type) {
+    case Types.TINY:
+    case Types.SHORT:
+    case Types.LONG:
+    case Types.INT24:
+    case Types.YEAR:
+      return packet.parseLengthCodedIntNoBigCheck();
+    case Types.LONGLONG:
+      if (supportBigNumbers && bigNumberStrings) {
+        return packet.parseLengthCodedIntString();
+      }
+      return packet.parseLengthCodedInt(supportBigNumbers);
+    case Types.FLOAT:
+    case Types.DOUBLE:
+      return packet.parseLengthCodedFloat();
+    case Types.NULL:
+    case Types.DECIMAL:
+    case Types.NEWDECIMAL:
+      if (config.decimalNumbers) {
+        return packet.parseLengthCodedFloat();
+      }
+      return packet.readLengthCodedString('ascii');
+    case Types.DATE:
+      if (helpers.typeMatch(type, dateStrings, Types)) {
+        return packet.readLengthCodedString('ascii');
+      }
+      return packet.parseDate(timezone);
+    case Types.DATETIME:
+    case Types.TIMESTAMP:
+      if (helpers.typeMatch(type, dateStrings, Types)) {
+        return packet.readLengthCodedString('ascii');
+      }
+      return packet.parseDateTime(timezone);
+    case Types.TIME:
+      return packet.readLengthCodedString('ascii');
+    case Types.GEOMETRY:
+      return packet.parseGeometryValue();
+    case Types.VECTOR:
+      return packet.parseVector();
+    case Types.JSON:
+      // Since for JSON columns mysql always returns charset 63 (BINARY),
+      // we have to handle it according to JSON specs and use "utf8",
+      // see https://github.com/sidorares/node-mysql2/issues/409
+      return config.jsonStrings
+        ? packet.readLengthCodedString('utf8')
+        : JSON.parse(packet.readLengthCodedString('utf8'));
+    default:
+      if (charset === Charsets.BINARY) {
+        return packet.readLengthCodedBuffer();
+      }
+      return packet.readLengthCodedString(encoding);
+  }
+}
+
+function createTypecastField(field, packet) {
+  return {
+    type: typeNames[field.columnType],
+    length: field.columnLength,
+    db: field.schema,
+    table: field.table,
+    name: field.name,
+    string: function (encoding = field.encoding) {
+      if (field.columnType === Types.JSON && encoding === field.encoding) {
+        // Since for JSON columns mysql always returns charset 63 (BINARY),
+        // we have to handle it according to JSON specs and use "utf8",
+        // see https://github.com/sidorares/node-mysql2/issues/1661
+        console.warn(
+          `typeCast: JSON column "${field.name}" is interpreted as BINARY by default, recommended to manually set utf8 encoding: \`field.string("utf8")\``
+        );
+      }
+      return packet.readLengthCodedString(encoding);
+    },
+    buffer: function () {
+      return packet.readLengthCodedBuffer();
+    },
+    geometry: function () {
+      return packet.parseGeometryValue();
+    },
+  };
+}
+
+function getTextParser(_fields, _options, config) {
+  return {
+    next(packet, fields, options) {
+      const result = options.rowsAsArray ? [] : {};
+      for (let i = 0; i < fields.length; i++) {
+        const field = fields[i];
+        const typeCast = options.typeCast ? options.typeCast : config.typeCast;
+        const next = () =>
+          readField({
+            packet,
+            type: field.columnType,
+            encoding: field.encoding,
+            charset: field.characterSet,
+            config,
+            options,
+          });
+
+        let value;
+
+        if (options.typeCast === false) {
+          value = packet.readLengthCodedBuffer();
+        } else if (typeof typeCast === 'function') {
+          value = typeCast(createTypecastField(field, packet), next);
+        } else {
+          value = next();
+        }
+
+        if (options.rowsAsArray) {
+          result.push(value);
+        } else if (typeof options.nestTables === 'string') {
+          result[
+            `${helpers.fieldEscape(field.table, false)}${options.nestTables}${helpers.fieldEscape(field.name, false)}`
+          ] = value;
+        } else if (options.nestTables) {
+          const tableName = helpers.fieldEscape(field.table, false);
+          if (!result[tableName]) {
+            result[tableName] = {};
+          }
+          result[tableName][helpers.fieldEscape(field.name, false)] = value;
+        } else {
+          result[helpers.fieldEscape(field.name, false)] = value;
+        }
+      }
+
+      return result;
+    },
+  };
+}
+
+module.exports = getTextParser;

backend/node_modules/mysql2/lib/parsers/string.js

@@ -0,0 +1,50 @@
+'use strict';
+
+const Iconv = require('iconv-lite');
+const { createLRU } = require('lru.min');
+
+const decoderCache = createLRU({
+  max: 500,
+});
+
+exports.decode = function (buffer, encoding, start, end, options) {
+  if (Buffer.isEncoding(encoding)) {
+    return buffer.toString(encoding, start, end);
+  }
+
+  // Optimize for common case: encoding="short_string", options=undefined.
+  let decoder;
+  if (!options) {
+    decoder = decoderCache.get(encoding);
+    if (!decoder) {
+      decoder = Iconv.getDecoder(encoding);
+      decoderCache.set(encoding, decoder);
+    }
+  } else {
+    const decoderArgs = { encoding, options };
+    const decoderKey = JSON.stringify(decoderArgs);
+    decoder = decoderCache.get(decoderKey);
+    if (!decoder) {
+      decoder = Iconv.getDecoder(decoderArgs.encoding, decoderArgs.options);
+      decoderCache.set(decoderKey, decoder);
+    }
+  }
+
+  const res = decoder.write(buffer.slice(start, end));
+  const trail = decoder.end();
+
+  return trail ? res + trail : res;
+};
+
+exports.encode = function (string, encoding, options) {
+  if (Buffer.isEncoding(encoding)) {
+    return Buffer.from(string, encoding);
+  }
+
+  const encoder = Iconv.getEncoder(encoding, options || {});
+
+  const res = encoder.write(string);
+  const trail = encoder.end();
+
+  return trail && trail.length > 0 ? Buffer.concat([res, trail]) : res;
+};

backend/node_modules/mysql2/lib/parsers/text_parser.js

@@ -0,0 +1,214 @@
+'use strict';
+
+const Types = require('../constants/types.js');
+const Charsets = require('../constants/charsets.js');
+const helpers = require('../helpers');
+const genFunc = require('generate-function');
+const parserCache = require('./parser_cache.js');
+
+const typeNames = [];
+for (const t in Types) {
+  typeNames[Types[t]] = t;
+}
+
+function readCodeFor(type, charset, encodingExpr, config, options) {
+  const supportBigNumbers = Boolean(
+    options.supportBigNumbers || config.supportBigNumbers
+  );
+  const bigNumberStrings = Boolean(
+    options.bigNumberStrings || config.bigNumberStrings
+  );
+  const timezone = options.timezone || config.timezone;
+  const dateStrings = options.dateStrings || config.dateStrings;
+
+  switch (type) {
+    case Types.TINY:
+    case Types.SHORT:
+    case Types.LONG:
+    case Types.INT24:
+    case Types.YEAR:
+      return 'packet.parseLengthCodedIntNoBigCheck()';
+    case Types.LONGLONG:
+      if (supportBigNumbers && bigNumberStrings) {
+        return 'packet.parseLengthCodedIntString()';
+      }
+      return `packet.parseLengthCodedInt(${supportBigNumbers})`;
+    case Types.FLOAT:
+    case Types.DOUBLE:
+      return 'packet.parseLengthCodedFloat()';
+    case Types.NULL:
+      return 'packet.readLengthCodedNumber()';
+    case Types.DECIMAL:
+    case Types.NEWDECIMAL:
+      if (config.decimalNumbers) {
+        return 'packet.parseLengthCodedFloat()';
+      }
+      return 'packet.readLengthCodedString("ascii")';
+    case Types.DATE:
+      if (helpers.typeMatch(type, dateStrings, Types)) {
+        return 'packet.readLengthCodedString("ascii")';
+      }
+      return `packet.parseDate(${helpers.srcEscape(timezone)})`;
+    case Types.DATETIME:
+    case Types.TIMESTAMP:
+      if (helpers.typeMatch(type, dateStrings, Types)) {
+        return 'packet.readLengthCodedString("ascii")';
+      }
+      return `packet.parseDateTime(${helpers.srcEscape(timezone)})`;
+    case Types.TIME:
+      return 'packet.readLengthCodedString("ascii")';
+    case Types.GEOMETRY:
+      return 'packet.parseGeometryValue()';
+    case Types.VECTOR:
+      return 'packet.parseVector()';
+    case Types.JSON:
+      // Since for JSON columns mysql always returns charset 63 (BINARY),
+      // we have to handle it according to JSON specs and use "utf8",
+      // see https://github.com/sidorares/node-mysql2/issues/409
+      return config.jsonStrings
+        ? 'packet.readLengthCodedString("utf8")'
+        : 'JSON.parse(packet.readLengthCodedString("utf8"))';
+    default:
+      if (charset === Charsets.BINARY) {
+        return 'packet.readLengthCodedBuffer()';
+      }
+      return `packet.readLengthCodedString(${encodingExpr})`;
+  }
+}
+
+function compile(fields, options, config) {
+  // use global typeCast if current query doesn't specify one
+  if (
+    typeof config.typeCast === 'function' &&
+    typeof options.typeCast !== 'function'
+  ) {
+    options.typeCast = config.typeCast;
+  }
+
+  function wrap(field, _this) {
+    return {
+      type: typeNames[field.columnType],
+      length: field.columnLength,
+      db: field.schema,
+      table: field.table,
+      name: field.name,
+      string: function (encoding = field.encoding) {
+        if (field.columnType === Types.JSON && encoding === field.encoding) {
+          // Since for JSON columns mysql always returns charset 63 (BINARY),
+          // we have to handle it according to JSON specs and use "utf8",
+          // see https://github.com/sidorares/node-mysql2/issues/1661
+          console.warn(
+            `typeCast: JSON column "${field.name}" is interpreted as BINARY by default, recommended to manually set utf8 encoding: \`field.string("utf8")\``
+          );
+        }
+
+        return _this.packet.readLengthCodedString(encoding);
+      },
+      buffer: function () {
+        return _this.packet.readLengthCodedBuffer();
+      },
+      geometry: function () {
+        return _this.packet.parseGeometryValue();
+      },
+    };
+  }
+
+  const parserFn = genFunc();
+
+  parserFn('(function () {')('return class TextRow {');
+
+  // constructor method
+  parserFn('constructor(fields) {');
+  // node-mysql typeCast compatibility wrapper
+  // see https://github.com/mysqljs/mysql/blob/96fdd0566b654436624e2375c7b6604b1f50f825/lib/protocol/packets/Field.js
+  if (typeof options.typeCast === 'function') {
+    parserFn('const _this = this;');
+    parserFn('for(let i=0; i<fields.length; ++i) {');
+    parserFn('this[`wrap${i}`] = wrap(fields[i], _this);');
+    parserFn('}');
+  }
+  parserFn('}');
+
+  // next method
+  parserFn('next(packet, fields, options) {');
+  parserFn('this.packet = packet;');
+  if (options.rowsAsArray) {
+    parserFn(`const result = new Array(${fields.length});`);
+  } else {
+    parserFn('const result = {};');
+  }
+
+  const resultTables = {};
+  let resultTablesArray = [];
+
+  if (options.nestTables === true) {
+    for (let i = 0; i < fields.length; i++) {
+      resultTables[fields[i].table] = 1;
+    }
+    resultTablesArray = Object.keys(resultTables);
+    for (let i = 0; i < resultTablesArray.length; i++) {
+      parserFn(`result[${helpers.fieldEscape(resultTablesArray[i])}] = {};`);
+    }
+  }
+
+  let lvalue = '';
+  let fieldName = '';
+  let tableName = '';
+  for (let i = 0; i < fields.length; i++) {
+    fieldName = helpers.fieldEscape(fields[i].name);
+    // parserFn(`// ${fieldName}: ${typeNames[fields[i].columnType]}`);
+
+    if (typeof options.nestTables === 'string') {
+      lvalue = `result[${helpers.fieldEscape(fields[i].table + options.nestTables + fields[i].name)}]`;
+    } else if (options.nestTables === true) {
+      tableName = helpers.fieldEscape(fields[i].table);
+
+      parserFn(`if (!result[${tableName}]) result[${tableName}] = {};`);
+      lvalue = `result[${tableName}][${fieldName}]`;
+    } else if (options.rowsAsArray) {
+      lvalue = `result[${i.toString(10)}]`;
+    } else {
+      lvalue = `result[${fieldName}]`;
+    }
+    if (options.typeCast === false) {
+      parserFn(`${lvalue} = packet.readLengthCodedBuffer();`);
+    } else {
+      const encodingExpr = `fields[${i}].encoding`;
+      const readCode = readCodeFor(
+        fields[i].columnType,
+        fields[i].characterSet,
+        encodingExpr,
+        config,
+        options
+      );
+      if (typeof options.typeCast === 'function') {
+        parserFn(
+          `${lvalue} = options.typeCast(this.wrap${i}, function() { return ${readCode} });`
+        );
+      } else {
+        parserFn(`${lvalue} = ${readCode};`);
+      }
+    }
+  }
+
+  parserFn('return result;');
+  parserFn('}');
+  parserFn('};')('})()');
+
+  if (config.debug) {
+    helpers.printDebugWithCode(
+      'Compiled text protocol row parser',
+      parserFn.toString()
+    );
+  }
+  if (typeof options.typeCast === 'function') {
+    return parserFn.toFunction({ wrap });
+  }
+  return parserFn.toFunction();
+}
+
+function getTextParser(fields, options, config) {
+  return parserCache.getParser('text', fields, options, config, compile);
+}
+
+module.exports = getTextParser;

backend/node_modules/mysql2/lib/pool.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const BasePool = require('./base/pool.js');
+
+class Pool extends BasePool {
+  promise(promiseImpl) {
+    const PromisePool = require('./promise/pool.js');
+    return new PromisePool(this, promiseImpl);
+  }
+}
+
+module.exports = Pool;

backend/node_modules/mysql2/lib/pool_cluster.js

@@ -0,0 +1,375 @@
+'use strict';
+
+const process = require('process');
+
+const Pool = require('./pool.js');
+const PoolConfig = require('./pool_config.js');
+const Connection = require('./connection.js');
+const EventEmitter = require('events').EventEmitter;
+
+/**
+ * Selector
+ */
+const makeSelector = {
+  RR() {
+    let index = 0;
+    return (clusterIds) => clusterIds[index++ % clusterIds.length];
+  },
+  RANDOM() {
+    return (clusterIds) =>
+      clusterIds[Math.floor(Math.random() * clusterIds.length)];
+  },
+  ORDER() {
+    return (clusterIds) => clusterIds[0];
+  },
+};
+
+const getMonotonicMilliseconds = function () {
+  let ms;
+
+  if (typeof process.hrtime === 'function') {
+    ms = process.hrtime();
+    ms = ms[0] * 1e3 + ms[1] * 1e-6;
+  } else {
+    ms = process.uptime() * 1000;
+  }
+
+  return Math.floor(ms);
+};
+
+const patternRegExp = function (pattern) {
+  if (pattern instanceof RegExp) {
+    return pattern;
+  }
+
+  const source = pattern
+    .replace(/([.+?^=!:${}()|[\]/\\])/g, '\\$1')
+    .replace(/\*/g, '.*');
+
+  return new RegExp(`^${source}$`);
+};
+
+class PoolNamespace {
+  constructor(cluster, pattern, selector) {
+    this._cluster = cluster;
+    this._pattern = pattern;
+    this._selector = makeSelector[selector]();
+  }
+
+  getConnection(cb) {
+    const clusterNode = this._getClusterNode();
+    if (clusterNode === null) {
+      let err = new Error('Pool does Not exist.');
+      err.code = 'POOL_NOEXIST';
+
+      if (this._cluster._findNodeIds(this._pattern, true).length !== 0) {
+        err = new Error('Pool does Not have online node.');
+        err.code = 'POOL_NONEONLINE';
+      }
+
+      return cb(err);
+    }
+    return this._cluster._getConnection(clusterNode, (err, connection) => {
+      if (err) {
+        if (
+          this._cluster._canRetry &&
+          this._cluster._findNodeIds(this._pattern).length !== 0
+        ) {
+          this._cluster.emit('warn', err);
+          return this.getConnection(cb);
+        }
+
+        return cb(err);
+      }
+      return cb(null, connection);
+    });
+  }
+
+  /**
+   * pool cluster query
+   * @param {*} sql
+   * @param {*} values
+   * @param {*} cb
+   * @returns query
+   */
+  query(sql, values, cb) {
+    const query = Connection.createQuery(sql, values, cb, {});
+    this.getConnection((err, conn) => {
+      if (err) {
+        if (typeof query.onResult === 'function') {
+          query.onResult(err);
+        } else {
+          query.emit('error', err);
+        }
+        return;
+      }
+      try {
+        conn.query(query).once('end', () => {
+          conn.release();
+        });
+      } catch (e) {
+        conn.release();
+        throw e;
+      }
+    });
+    return query;
+  }
+
+  /**
+   * pool cluster execute
+   * @param {*} sql
+   * @param {*} values
+   * @param {*} cb
+   */
+  execute(sql, values, cb) {
+    if (typeof values === 'function') {
+      cb = values;
+      values = [];
+    }
+    this.getConnection((err, conn) => {
+      if (err) {
+        return cb(err);
+      }
+      try {
+        conn.execute(sql, values, cb).once('end', () => {
+          conn.release();
+        });
+      } catch (e) {
+        conn.release();
+        throw e;
+      }
+    });
+  }
+
+  _getClusterNode() {
+    const foundNodeIds = this._cluster._findNodeIds(this._pattern);
+    if (foundNodeIds.length === 0) {
+      return null;
+    }
+    const nodeId =
+      foundNodeIds.length === 1
+        ? foundNodeIds[0]
+        : this._selector(foundNodeIds);
+    return this._cluster._getNode(nodeId);
+  }
+}
+
+class PoolCluster extends EventEmitter {
+  constructor(config) {
+    super();
+    config = config || {};
+    this._canRetry =
+      typeof config.canRetry === 'undefined' ? true : config.canRetry;
+    this._removeNodeErrorCount = config.removeNodeErrorCount || 5;
+    this._restoreNodeTimeout = config.restoreNodeTimeout || 0;
+    this._defaultSelector = config.defaultSelector || 'RR';
+    this._closed = false;
+    this._lastId = 0;
+    this._nodes = {};
+    this._serviceableNodeIds = [];
+    this._namespaces = {};
+    this._findCaches = {};
+  }
+
+  of(pattern, selector) {
+    pattern = pattern || '*';
+    selector = selector || this._defaultSelector;
+    selector = selector.toUpperCase();
+    if (!makeSelector[selector] === 'undefined') {
+      selector = this._defaultSelector;
+    }
+    const key = pattern + selector;
+    if (typeof this._namespaces[key] === 'undefined') {
+      this._namespaces[key] = new PoolNamespace(this, pattern, selector);
+    }
+    return this._namespaces[key];
+  }
+
+  add(id, config) {
+    if (typeof id === 'object') {
+      config = id;
+      id = `CLUSTER::${++this._lastId}`;
+    }
+    if (typeof this._nodes[id] === 'undefined') {
+      this._nodes[id] = {
+        id: id,
+        errorCount: 0,
+        pool: new Pool({ config: new PoolConfig(config) }),
+        _offlineUntil: 0,
+      };
+      this._serviceableNodeIds.push(id);
+      this._clearFindCaches();
+    }
+  }
+
+  remove(pattern) {
+    const foundNodeIds = this._findNodeIds(pattern, true);
+
+    for (let i = 0; i < foundNodeIds.length; i++) {
+      const node = this._getNode(foundNodeIds[i]);
+
+      if (node) {
+        this._removeNode(node);
+      }
+    }
+  }
+
+  getConnection(pattern, selector, cb) {
+    let namespace;
+    if (typeof pattern === 'function') {
+      cb = pattern;
+      namespace = this.of();
+    } else {
+      if (typeof selector === 'function') {
+        cb = selector;
+        selector = this._defaultSelector;
+      }
+      namespace = this.of(pattern, selector);
+    }
+    namespace.getConnection(cb);
+  }
+
+  [Symbol.dispose]() {
+    if (!this._closed) {
+      this.end();
+    }
+  }
+
+  end(callback) {
+    const cb =
+      callback !== undefined
+        ? callback
+        : (err) => {
+            if (err) {
+              throw err;
+            }
+          };
+    if (this._closed) {
+      process.nextTick(cb);
+      return;
+    }
+
+    this._closed = true;
+
+    let calledBack = false;
+    let waitingClose = 0;
+    const onEnd = (err) => {
+      if (!calledBack && (err || --waitingClose <= 0)) {
+        calledBack = true;
+        return cb(err);
+      }
+    };
+
+    for (const id in this._nodes) {
+      waitingClose++;
+      this._nodes[id].pool.end(onEnd);
+    }
+
+    if (waitingClose === 0) {
+      process.nextTick(onEnd);
+    }
+  }
+
+  _findNodeIds(pattern, includeOffline) {
+    let currentTime = 0;
+    let foundNodeIds = this._findCaches[pattern];
+
+    if (foundNodeIds === undefined) {
+      const expression = patternRegExp(pattern);
+
+      foundNodeIds = this._serviceableNodeIds.filter((id) =>
+        id.match(expression)
+      );
+    }
+
+    this._findCaches[pattern] = foundNodeIds;
+
+    if (includeOffline) {
+      return foundNodeIds;
+    }
+
+    return foundNodeIds.filter((nodeId) => {
+      const node = this._getNode(nodeId);
+
+      if (!node._offlineUntil) {
+        return true;
+      }
+
+      if (!currentTime) {
+        currentTime = getMonotonicMilliseconds();
+      }
+
+      return node._offlineUntil <= currentTime;
+    });
+  }
+
+  _getNode(id) {
+    return this._nodes[id] || null;
+  }
+
+  _increaseErrorCount(node) {
+    const errorCount = ++node.errorCount;
+
+    if (this._removeNodeErrorCount > errorCount) {
+      return;
+    }
+
+    if (this._restoreNodeTimeout > 0) {
+      node._offlineUntil =
+        getMonotonicMilliseconds() + this._restoreNodeTimeout;
+      this.emit('offline', node.id);
+      return;
+    }
+
+    this._removeNode(node);
+    this.emit('remove', node.id);
+  }
+
+  _decreaseErrorCount(node) {
+    let errorCount = node.errorCount;
+
+    if (errorCount > this._removeNodeErrorCount) {
+      errorCount = this._removeNodeErrorCount;
+    }
+
+    if (errorCount < 1) {
+      errorCount = 1;
+    }
+
+    node.errorCount = errorCount - 1;
+
+    if (node._offlineUntil) {
+      node._offlineUntil = 0;
+      this.emit('online', node.id);
+    }
+  }
+
+  _getConnection(node, cb) {
+    node.pool.getConnection((err, connection) => {
+      if (err) {
+        this._increaseErrorCount(node);
+        return cb(err);
+      }
+      this._decreaseErrorCount(node);
+
+      connection._clusterId = node.id;
+      return cb(null, connection);
+    });
+  }
+
+  _removeNode(node) {
+    const index = this._serviceableNodeIds.indexOf(node.id);
+    if (index !== -1) {
+      this._serviceableNodeIds.splice(index, 1);
+      delete this._nodes[node.id];
+      this._clearFindCaches();
+      node.pool.end();
+    }
+  }
+
+  _clearFindCaches() {
+    this._findCaches = {};
+  }
+}
+
+module.exports = PoolCluster;

backend/node_modules/mysql2/lib/pool_config.js

@@ -0,0 +1,34 @@
+'use strict';
+
+const ConnectionConfig = require('./connection_config.js');
+
+class PoolConfig {
+  constructor(options) {
+    if (typeof options === 'string') {
+      options = ConnectionConfig.parseUrl(options);
+    }
+    this.connectionConfig = new ConnectionConfig(options);
+    this.waitForConnections =
+      options.waitForConnections === undefined
+        ? true
+        : Boolean(options.waitForConnections);
+    this.connectionLimit = isNaN(options.connectionLimit)
+      ? 10
+      : Number(options.connectionLimit);
+    this.maxIdle = isNaN(options.maxIdle)
+      ? this.connectionLimit
+      : Number(options.maxIdle);
+    this.idleTimeout = isNaN(options.idleTimeout)
+      ? 60000
+      : Number(options.idleTimeout);
+    this.queueLimit = isNaN(options.queueLimit)
+      ? 0
+      : Number(options.queueLimit);
+    this.resetOnRelease =
+      options.resetOnRelease === undefined
+        ? false
+        : Boolean(options.resetOnRelease);
+  }
+}
+
+module.exports = PoolConfig;

backend/node_modules/mysql2/lib/pool_connection.js

@@ -0,0 +1,81 @@
+'use strict';
+
+const Connection = require('./connection.js');
+
+class PoolConnection extends Connection {
+  constructor(pool, options) {
+    super(options);
+    this._pool = pool;
+    this._released = false;
+    this.lastActiveTime = Date.now();
+    this.once('end', () => {
+      this._removeFromPool();
+    });
+    this.once('error', () => {
+      this._removeFromPool();
+    });
+  }
+
+  release() {
+    if (this._released) {
+      return;
+    }
+    if (!this._pool || this._pool._closed) {
+      return;
+    }
+    this._released = true;
+    this.lastActiveTime = Date.now();
+    this._pool.releaseConnection(this);
+  }
+
+  [Symbol.dispose]() {
+    this.release();
+  }
+
+  end(callback) {
+    if (this.config.gracefulEnd) {
+      this._removeFromPool();
+      super.end(callback);
+
+      return;
+    }
+
+    const err = new Error(
+      'Calling conn.end() to release a pooled connection is ' +
+        'deprecated. In next version calling conn.end() will be ' +
+        'restored to default conn.end() behavior. Use ' +
+        'conn.release() instead.'
+    );
+    this.emit('warn', err);
+    console.warn(err.message);
+    this.release();
+    if (typeof callback === 'function') {
+      callback();
+    }
+  }
+
+  destroy() {
+    this._removeFromPool();
+    super.destroy();
+  }
+
+  _removeFromPool() {
+    if (!this._pool || this._pool._closed) {
+      return;
+    }
+    const pool = this._pool;
+    this._pool = null;
+    pool._removeConnection(this);
+  }
+
+  promise(promiseImpl) {
+    const PromisePoolConnection = require('./promise/pool_connection.js');
+    return new PromisePoolConnection(this, promiseImpl);
+  }
+}
+
+PoolConnection.statementKey = Connection.statementKey;
+module.exports = PoolConnection;
+
+// TODO: Remove this when we are removing PoolConnection#end
+PoolConnection.prototype._realEnd = Connection.prototype.end;

backend/node_modules/mysql2/lib/promise/capture_local_err.js

@@ -0,0 +1,25 @@
+'use strict';
+
+/** @param {Function} constructorOpt Passed to Error.captureStackTrace (omit this frame from stacks). */
+function captureStackHolder(constructorOpt) {
+  const holder = {};
+  Error.captureStackTrace(holder, constructorOpt);
+  return holder;
+}
+
+/**
+ * Replace `err.stack` frames with the capture from `holder`, keeping the
+ * callback error instance and its MySQL fields.
+ *
+ * @param {Error} err
+ * @param {{ stack?: string }} holder
+ */
+function applyCapturedStack(err, holder) {
+  const stack = holder && holder.stack;
+  if (typeof stack !== 'string' || !stack) return;
+  const lines = stack.split('\n');
+  lines[0] = `${err.name}: ${err.message}`;
+  err.stack = lines.join('\n');
+}
+
+module.exports = { captureStackHolder, applyCapturedStack };

backend/node_modules/mysql2/lib/promise/connection.js

@@ -0,0 +1,237 @@
+'use strict';
+
+const EventEmitter = require('events').EventEmitter;
+const PromisePreparedStatementInfo = require('./prepared_statement_info.js');
+const {
+  captureStackHolder,
+  applyCapturedStack,
+} = require('./capture_local_err.js');
+const makeDoneCb = require('./make_done_cb.js');
+const inheritEvents = require('./inherit_events.js');
+const BaseConnection = require('../base/connection.js');
+
+class PromiseConnection extends EventEmitter {
+  constructor(connection, promiseImpl) {
+    super();
+    this.connection = connection;
+    this.Promise = promiseImpl || Promise;
+    inheritEvents(connection, this, [
+      'error',
+      'drain',
+      'connect',
+      'end',
+      'enqueue',
+    ]);
+  }
+
+  release() {
+    this.connection.release();
+  }
+
+  query(query, params) {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(PromiseConnection.prototype.query);
+    if (typeof params === 'function') {
+      throw new Error(
+        'Callback function is not available with promise clients.'
+      );
+    }
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      if (params !== undefined) {
+        c.query(query, params, done);
+      } else {
+        c.query(query, done);
+      }
+    });
+  }
+
+  execute(query, params) {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(PromiseConnection.prototype.execute);
+    if (typeof params === 'function') {
+      throw new Error(
+        'Callback function is not available with promise clients.'
+      );
+    }
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      if (params !== undefined) {
+        c.execute(query, params, done);
+      } else {
+        c.execute(query, done);
+      }
+    });
+  }
+
+  end() {
+    return new this.Promise((resolve) => {
+      this.connection.end(resolve);
+    });
+  }
+
+  async [Symbol.asyncDispose]() {
+    if (!this.connection._closing) {
+      await this.end();
+    }
+  }
+
+  beginTransaction() {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(
+      PromiseConnection.prototype.beginTransaction
+    );
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      c.beginTransaction(done);
+    });
+  }
+
+  commit() {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(PromiseConnection.prototype.commit);
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      c.commit(done);
+    });
+  }
+
+  rollback() {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(
+      PromiseConnection.prototype.rollback
+    );
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      c.rollback(done);
+    });
+  }
+
+  ping() {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(PromiseConnection.prototype.ping);
+    return new this.Promise((resolve, reject) => {
+      c.ping((err) => {
+        if (err) {
+          applyCapturedStack(err, stackHolder);
+          reject(err);
+        } else {
+          resolve(true);
+        }
+      });
+    });
+  }
+
+  reset() {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(PromiseConnection.prototype.reset);
+    return new this.Promise((resolve, reject) => {
+      c.reset((err) => {
+        if (err) {
+          applyCapturedStack(err, stackHolder);
+          reject(err);
+        } else {
+          resolve();
+        }
+      });
+    });
+  }
+
+  connect() {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(PromiseConnection.prototype.connect);
+    return new this.Promise((resolve, reject) => {
+      c.connect((err, param) => {
+        if (err) {
+          applyCapturedStack(err, stackHolder);
+          reject(err);
+        } else {
+          resolve(param);
+        }
+      });
+    });
+  }
+
+  prepare(options) {
+    const c = this.connection;
+    const promiseImpl = this.Promise;
+    const stackHolder = captureStackHolder(PromiseConnection.prototype.prepare);
+    return new this.Promise((resolve, reject) => {
+      c.prepare(options, (err, statement) => {
+        if (err) {
+          applyCapturedStack(err, stackHolder);
+          reject(err);
+        } else {
+          const wrappedStatement = new PromisePreparedStatementInfo(
+            statement,
+            promiseImpl
+          );
+          resolve(wrappedStatement);
+        }
+      });
+    });
+  }
+
+  changeUser(options) {
+    const c = this.connection;
+    const stackHolder = captureStackHolder(
+      PromiseConnection.prototype.changeUser
+    );
+    return new this.Promise((resolve, reject) => {
+      c.changeUser(options, (err) => {
+        if (err) {
+          applyCapturedStack(err, stackHolder);
+          reject(err);
+        } else {
+          resolve();
+        }
+      });
+    });
+  }
+
+  get config() {
+    return this.connection.config;
+  }
+
+  get threadId() {
+    return this.connection.threadId;
+  }
+}
+// patching PromiseConnection
+// create facade functions for prototype functions on "Connection" that are not yet
+// implemented with PromiseConnection
+
+// proxy synchronous functions only
+(function (functionsToWrap) {
+  for (let i = 0; functionsToWrap && i < functionsToWrap.length; i++) {
+    const func = functionsToWrap[i];
+
+    if (
+      typeof BaseConnection.prototype[func] === 'function' &&
+      PromiseConnection.prototype[func] === undefined
+    ) {
+      PromiseConnection.prototype[func] = (function factory(funcName) {
+        return function () {
+          return BaseConnection.prototype[funcName].apply(
+            this.connection,
+            arguments
+          );
+        };
+      })(func);
+    }
+  }
+})([
+  // synchronous functions
+  'close',
+  'createBinlogStream',
+  'destroy',
+  'escape',
+  'escapeId',
+  'format',
+  'pause',
+  'pipe',
+  'resume',
+  'unprepare',
+]);
+
+module.exports = PromiseConnection;

backend/node_modules/mysql2/lib/promise/inherit_events.js

@@ -0,0 +1,27 @@
+'use strict';
+
+function inheritEvents(source, target, events) {
+  const listeners = {};
+  target
+    .on('newListener', (eventName) => {
+      if (events.indexOf(eventName) >= 0 && !target.listenerCount(eventName)) {
+        source.on(
+          eventName,
+          (listeners[eventName] = function () {
+            const args = [].slice.call(arguments);
+            args.unshift(eventName);
+
+            target.emit.apply(target, args);
+          })
+        );
+      }
+    })
+    .on('removeListener', (eventName) => {
+      if (events.indexOf(eventName) >= 0 && !target.listenerCount(eventName)) {
+        source.removeListener(eventName, listeners[eventName]);
+        delete listeners[eventName];
+      }
+    });
+}
+
+module.exports = inheritEvents;

backend/node_modules/mysql2/lib/promise/make_done_cb.js

@@ -0,0 +1,16 @@
+'use strict';
+
+const { applyCapturedStack } = require('./capture_local_err.js');
+
+function makeDoneCb(resolve, reject, stackHolder) {
+  return function (err, rows, fields) {
+    if (err) {
+      applyCapturedStack(err, stackHolder);
+      reject(err);
+    } else {
+      resolve([rows, fields]);
+    }
+  };
+}
+
+module.exports = makeDoneCb;

backend/node_modules/mysql2/lib/promise/pool.js

@@ -0,0 +1,118 @@
+'use strict';
+
+const EventEmitter = require('events').EventEmitter;
+const {
+  captureStackHolder,
+  applyCapturedStack,
+} = require('./capture_local_err.js');
+const makeDoneCb = require('./make_done_cb.js');
+const PromisePoolConnection = require('./pool_connection.js');
+const inheritEvents = require('./inherit_events.js');
+const BasePool = require('../base/pool.js');
+
+class PromisePool extends EventEmitter {
+  constructor(pool, thePromise) {
+    super();
+    this.pool = pool;
+    this.Promise = thePromise || Promise;
+    inheritEvents(pool, this, ['acquire', 'connection', 'enqueue', 'release']);
+  }
+
+  getConnection() {
+    const corePool = this.pool;
+    return new this.Promise((resolve, reject) => {
+      corePool.getConnection((err, coreConnection) => {
+        if (err) {
+          reject(err);
+        } else {
+          resolve(new PromisePoolConnection(coreConnection, this.Promise));
+        }
+      });
+    });
+  }
+
+  releaseConnection(connection) {
+    if (connection instanceof PromisePoolConnection) connection.release();
+  }
+
+  query(sql, args) {
+    const corePool = this.pool;
+    const stackHolder = captureStackHolder(PromisePool.prototype.query);
+    if (typeof args === 'function') {
+      throw new Error(
+        'Callback function is not available with promise clients.'
+      );
+    }
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      if (args !== undefined) {
+        corePool.query(sql, args, done);
+      } else {
+        corePool.query(sql, done);
+      }
+    });
+  }
+
+  execute(sql, args) {
+    const corePool = this.pool;
+    const stackHolder = captureStackHolder(PromisePool.prototype.execute);
+    if (typeof args === 'function') {
+      throw new Error(
+        'Callback function is not available with promise clients.'
+      );
+    }
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      if (args) {
+        corePool.execute(sql, args, done);
+      } else {
+        corePool.execute(sql, done);
+      }
+    });
+  }
+
+  end() {
+    const corePool = this.pool;
+    const stackHolder = captureStackHolder(PromisePool.prototype.end);
+    return new this.Promise((resolve, reject) => {
+      corePool.end((err) => {
+        if (err) {
+          applyCapturedStack(err, stackHolder);
+          reject(err);
+        } else {
+          resolve();
+        }
+      });
+    });
+  }
+
+  async [Symbol.asyncDispose]() {
+    if (!this.pool._closed) {
+      await this.end();
+    }
+  }
+}
+
+(function (functionsToWrap) {
+  for (let i = 0; functionsToWrap && i < functionsToWrap.length; i++) {
+    const func = functionsToWrap[i];
+
+    if (
+      typeof BasePool.prototype[func] === 'function' &&
+      PromisePool.prototype[func] === undefined
+    ) {
+      PromisePool.prototype[func] = (function factory(funcName) {
+        return function () {
+          return BasePool.prototype[funcName].apply(this.pool, arguments);
+        };
+      })(func);
+    }
+  }
+})([
+  // synchronous functions
+  'escape',
+  'escapeId',
+  'format',
+]);
+
+module.exports = PromisePool;

backend/node_modules/mysql2/lib/promise/pool_cluster.js

@@ -0,0 +1,59 @@
+'use strict';
+
+const { captureStackHolder } = require('./capture_local_err.js');
+const PromisePoolConnection = require('./pool_connection');
+const makeDoneCb = require('./make_done_cb');
+
+class PromisePoolNamespace {
+  constructor(poolNamespace, thePromise) {
+    this.poolNamespace = poolNamespace;
+    this.Promise = thePromise || Promise;
+  }
+
+  getConnection() {
+    const corePoolNamespace = this.poolNamespace;
+    return new this.Promise((resolve, reject) => {
+      corePoolNamespace.getConnection((err, coreConnection) => {
+        if (err) {
+          reject(err);
+        } else {
+          resolve(new PromisePoolConnection(coreConnection, this.Promise));
+        }
+      });
+    });
+  }
+
+  query(sql, values) {
+    const corePoolNamespace = this.poolNamespace;
+    const stackHolder = captureStackHolder(
+      PromisePoolNamespace.prototype.query
+    );
+    if (typeof values === 'function') {
+      throw new Error(
+        'Callback function is not available with promise clients.'
+      );
+    }
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      corePoolNamespace.query(sql, values, done);
+    });
+  }
+
+  execute(sql, values) {
+    const corePoolNamespace = this.poolNamespace;
+    const stackHolder = captureStackHolder(
+      PromisePoolNamespace.prototype.execute
+    );
+    if (typeof values === 'function') {
+      throw new Error(
+        'Callback function is not available with promise clients.'
+      );
+    }
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      corePoolNamespace.execute(sql, values, done);
+    });
+  }
+}
+
+module.exports = PromisePoolNamespace;

backend/node_modules/mysql2/lib/promise/pool_connection.js

@@ -0,0 +1,19 @@
+'use strict';
+
+const PromiseConnection = require('./connection.js');
+
+class PromisePoolConnection extends PromiseConnection {
+  constructor(connection, promiseImpl) {
+    super(connection, promiseImpl);
+  }
+
+  destroy() {
+    return this.connection.destroy();
+  }
+
+  async [Symbol.asyncDispose]() {
+    this.release();
+  }
+}
+
+module.exports = PromisePoolConnection;

backend/node_modules/mysql2/lib/promise/prepared_statement_info.js

@@ -0,0 +1,35 @@
+'use strict';
+
+const { captureStackHolder } = require('./capture_local_err.js');
+const makeDoneCb = require('./make_done_cb.js');
+
+class PromisePreparedStatementInfo {
+  constructor(statement, promiseImpl) {
+    this.statement = statement;
+    this.Promise = promiseImpl;
+  }
+
+  execute(parameters) {
+    const s = this.statement;
+    const stackHolder = captureStackHolder(
+      PromisePreparedStatementInfo.prototype.execute
+    );
+    return new this.Promise((resolve, reject) => {
+      const done = makeDoneCb(resolve, reject, stackHolder);
+      if (parameters) {
+        s.execute(parameters, done);
+      } else {
+        s.execute(done);
+      }
+    });
+  }
+
+  close() {
+    return new this.Promise((resolve) => {
+      this.statement.close();
+      resolve();
+    });
+  }
+}
+
+module.exports = PromisePreparedStatementInfo;

backend/node_modules/mysql2/lib/results_stream.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const Readable = require('stream').Readable;
+
+// copy-paste from https://github.com/mysqljs/mysql/blob/master/lib/protocol/sequences/Query.js
+module.exports = function (command, connectionStream) {
+  command.stream = function (options) {
+    let stream;
+
+    options = options || {};
+    options.objectMode = true;
+    ((stream = new Readable(options)),
+      (stream._read = function () {
+        connectionStream.resume();
+      }));
+
+    this.on('result', (row, i) => {
+      if (!stream.push(row)) {
+        connectionStream.pause();
+      }
+      stream.emit('result', row, i); // replicate old emitter
+    });
+
+    this.on('error', (err) => {
+      stream.emit('error', err); // Pass on any errors
+    });
+
+    this.on('end', () => {
+      stream.push(null); // pushing null, indicating EOF
+    });
+
+    this.on('fields', (fields, i) => {
+      stream.emit('fields', fields, i); // replicate old emitter
+    });
+
+    return stream;
+  };
+};

backend/node_modules/mysql2/lib/server.js

@@ -0,0 +1,37 @@
+'use strict';
+
+const net = require('net');
+const EventEmitter = require('events').EventEmitter;
+
+const Connection = require('./connection');
+const ConnectionConfig = require('./connection_config');
+
+// TODO: inherit Server from net.Server
+class Server extends EventEmitter {
+  constructor() {
+    super();
+    this.connections = [];
+    this._server = net.createServer(this._handleConnection.bind(this));
+  }
+
+  _handleConnection(socket) {
+    const connectionConfig = new ConnectionConfig({
+      stream: socket,
+      isServer: true,
+    });
+    const connection = new Connection({ config: connectionConfig });
+    this.emit('connection', connection);
+  }
+
+  listen(port) {
+    this._port = port;
+    this._server.listen.apply(this._server, arguments);
+    return this;
+  }
+
+  close(cb) {
+    this._server.close(cb);
+  }
+}
+
+module.exports = Server;

backend/node_modules/mysql2/lib/tracing.js

@@ -0,0 +1,81 @@
+'use strict';
+
+const process = require('process');
+
+// Safe load: use getBuiltinModule if available, fallback to require, catch if unavailable
+const dc = (() => {
+  try {
+    return 'getBuiltinModule' in process
+      ? process.getBuiltinModule('node:diagnostics_channel')
+      : require('node:diagnostics_channel');
+  } catch {
+    return undefined;
+  }
+})();
+
+const hasTracingChannel = typeof dc?.tracingChannel === 'function';
+
+const queryChannel = hasTracingChannel
+  ? dc.tracingChannel('mysql2:query')
+  : undefined;
+
+const executeChannel = hasTracingChannel
+  ? dc.tracingChannel('mysql2:execute')
+  : undefined;
+
+const connectChannel = hasTracingChannel
+  ? dc.tracingChannel('mysql2:connect')
+  : undefined;
+
+const poolConnectChannel = hasTracingChannel
+  ? dc.tracingChannel('mysql2:pool:connect')
+  : undefined;
+
+function getServerContext(config) {
+  if (config.socketPath) {
+    return { serverAddress: config.socketPath, serverPort: undefined };
+  }
+  return {
+    serverAddress: config.host || 'localhost',
+    serverPort: config.port || 3306,
+  };
+}
+
+// Node 20+: TracingChannel has an aggregated hasSubscribers getter.
+// Node 18.x: that getter is missing (undefined), fall back to start sub-channel.
+function shouldTrace(channel) {
+  if (channel === undefined || channel === null) {
+    return false;
+  }
+  return channel.hasSubscribers ?? channel.start?.hasSubscribers ?? false;
+}
+
+// Generic traceCallback wrapper — calls fn synchronously, wraps the callback
+// at args[position] to emit asyncStart/asyncEnd/error. No promises involved.
+function traceCallback(channel, fn, position, context, thisArg, ...args) {
+  if (shouldTrace(channel)) {
+    return channel.traceCallback(fn, position, context(), thisArg, ...args);
+  }
+  return fn.apply(thisArg, args);
+}
+
+// tracePromise for operations that are inherently async (connection handshake)
+function tracePromise(channel, fn, contextFactory) {
+  if (shouldTrace(channel)) {
+    return channel.tracePromise(fn, contextFactory());
+  }
+  return fn();
+}
+
+module.exports = {
+  dc,
+  hasTracingChannel,
+  shouldTrace,
+  queryChannel,
+  executeChannel,
+  connectChannel,
+  poolConnectChannel,
+  getServerContext,
+  traceCallback,
+  tracePromise,
+};

backend/node_modules/mysql2/node_modules/iconv-lite/LICENSE

@@ -0,0 +1,21 @@
+Copyright (c) 2011 Alexander Shtuchkin
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+

backend/node_modules/mysql2/node_modules/iconv-lite/README.md

@@ -0,0 +1,138 @@
+## iconv-lite: Pure JS character encoding conversion
+
+[![NPM Version][npm-version-image]][npm-url]
+[![NPM Downloads][npm-downloads-image]][npm-downloads-url]
+[![License][license-image]][license-url]
+[![NPM Install Size][npm-install-size-image]][npm-install-size-url]
+
+* No need for native code compilation. Quick to install, works on Windows, Web, and in sandboxed environments.
+* Used in popular projects like [Express.js (body_parser)](https://github.com/expressjs/body-parser), 
+  [Grunt](http://gruntjs.com/), [Nodemailer](http://www.nodemailer.com/), [Yeoman](http://yeoman.io/) and others.
+* Faster than [node-iconv](https://github.com/bnoordhuis/node-iconv) (see below for performance comparison).
+* Intuitive encode/decode API, including Streaming support.
+* In-browser usage via [browserify](https://github.com/substack/node-browserify) or [webpack](https://webpack.js.org/) (~180kb gzip compressed with Buffer shim included).
+* Typescript [type definition file](https://github.com/ashtuchkin/iconv-lite/blob/master/lib/index.d.ts) included.
+* React Native is supported (need to install `stream` module to enable Streaming API).
+
+## Usage
+
+### Basic API
+
+```javascript
+var iconv = require('iconv-lite');
+
+// Convert from an encoded buffer to a js string.
+str = iconv.decode(Buffer.from([0x68, 0x65, 0x6c, 0x6c, 0x6f]), 'win1251');
+
+// Convert from a js string to an encoded buffer.
+buf = iconv.encode("Sample input string", 'win1251');
+
+// Check if encoding is supported
+iconv.encodingExists("us-ascii")
+```
+
+### Streaming API
+
+```javascript
+// Decode stream (from binary data stream to js strings)
+http.createServer(function(req, res) {
+    var converterStream = iconv.decodeStream('win1251');
+    req.pipe(converterStream);
+
+    converterStream.on('data', function(str) {
+        console.log(str); // Do something with decoded strings, chunk-by-chunk.
+    });
+});
+
+// Convert encoding streaming example
+fs.createReadStream('file-in-win1251.txt')
+    .pipe(iconv.decodeStream('win1251'))
+    .pipe(iconv.encodeStream('ucs2'))
+    .pipe(fs.createWriteStream('file-in-ucs2.txt'));
+
+// Sugar: all encode/decode streams have .collect(cb) method to accumulate data.
+http.createServer(function(req, res) {
+    req.pipe(iconv.decodeStream('win1251')).collect(function(err, body) {
+        assert(typeof body == 'string');
+        console.log(body); // full request body string
+    });
+});
+```
+
+## Supported encodings
+
+ *  All node.js native encodings: utf8, ucs2 / utf16-le, ascii, binary, base64, hex.
+ *  Additional unicode encodings: utf16, utf16-be, utf-7, utf-7-imap, utf32, utf32-le, and utf32-be.
+ *  All widespread singlebyte encodings: Windows 125x family, ISO-8859 family, 
+    IBM/DOS codepages, Macintosh family, KOI8 family, all others supported by iconv library. 
+    Aliases like 'latin1', 'us-ascii' also supported.
+ *  All widespread multibyte encodings: CP932, CP936, CP949, CP950, GB2312, GBK, GB18030, Big5, Shift_JIS, EUC-JP.
+
+See [all supported encodings on wiki](https://github.com/ashtuchkin/iconv-lite/wiki/Supported-Encodings).
+
+Most singlebyte encodings are generated automatically from [node-iconv](https://github.com/bnoordhuis/node-iconv). Thank you Ben Noordhuis and libiconv authors!
+
+Multibyte encodings are generated from [Unicode.org mappings](http://www.unicode.org/Public/MAPPINGS/) and [WHATWG Encoding Standard mappings](http://encoding.spec.whatwg.org/). Thank you, respective authors!
+
+## Encoding/decoding speed
+
+Comparison with node-iconv module (1000x256kb, on MacBook Pro, Core i5/2.6 GHz, Node v0.12.0). 
+Note: your results may vary, so please always check on your hardware.
+
+    operation             iconv@2.1.4   iconv-lite@0.4.7
+    ----------------------------------------------------------
+    encode('win1251')     ~96 Mb/s      ~320 Mb/s
+    decode('win1251')     ~95 Mb/s      ~246 Mb/s
+
+## BOM handling
+
+ * Decoding: BOM is stripped by default, unless overridden by passing `stripBOM: false` in options
+   (f.ex. `iconv.decode(buf, enc, {stripBOM: false})`).
+   A callback might also be given as a `stripBOM` parameter - it'll be called if BOM character was actually found.
+ * If you want to detect UTF-8 BOM when decoding other encodings, use [node-autodetect-decoder-stream](https://github.com/danielgindi/node-autodetect-decoder-stream) module.
+ * Encoding: No BOM added, unless overridden by `addBOM: true` option.
+
+## UTF-16 Encodings
+
+This library supports UTF-16LE, UTF-16BE and UTF-16 encodings. First two are straightforward, but UTF-16 is trying to be
+smart about endianness in the following ways:
+ * Decoding: uses BOM and 'spaces heuristic' to determine input endianness. Default is UTF-16LE, but can be 
+   overridden with `defaultEncoding: 'utf-16be'` option. Strips BOM unless `stripBOM: false`.
+ * Encoding: uses UTF-16LE and writes BOM by default. Use `addBOM: false` to override.
+
+## UTF-32 Encodings
+
+This library supports UTF-32LE, UTF-32BE and UTF-32 encodings. Like the UTF-16 encoding above, UTF-32 defaults to UTF-32LE, but uses BOM and 'spaces heuristics' to determine input endianness. 
+ * The default of UTF-32LE can be overridden with the `defaultEncoding: 'utf-32be'` option. Strips BOM unless `stripBOM: false`.
+ * Encoding: uses UTF-32LE and writes BOM by default. Use `addBOM: false` to override. (`defaultEncoding: 'utf-32be'` can also be used here to change encoding.)
+
+## Other notes
+
+When decoding, be sure to supply a Buffer to decode() method, otherwise [bad things usually happen](https://github.com/ashtuchkin/iconv-lite/wiki/Use-Buffers-when-decoding).  
+Untranslatable characters are set to � or ?. No transliteration is currently supported.  
+Node versions 0.10.31 and 0.11.13 are buggy, don't use them (see [#65](https://github.com/ashtuchkin/iconv-lite/issues/65), [#77](https://github.com/ashtuchkin/iconv-lite/issues/77)).  
+
+## Testing
+
+```sh
+git clone git@github.com:ashtuchkin/iconv-lite.git
+cd iconv-lite
+npm install
+npm test
+    
+# To view performance:
+npm run test:performance
+
+# To view test coverage: 
+npm run test:cov
+open coverage/index.html
+```
+
+[npm-downloads-image]: https://badgen.net/npm/dm/iconv-lite
+[npm-downloads-url]: https://npmcharts.com/compare/iconv-lite?minimal=true
+[npm-url]: https://npmjs.org/package/iconv-lite
+[npm-version-image]: https://badgen.net/npm/v/iconv-lite
+[npm-install-size-image]: https://badgen.net/packagephobia/install/iconv-lite
+[npm-install-size-url]: https://packagephobia.com/result?p=iconv-lite
+[license-image]: https://img.shields.io/npm/l/iconv-lite.svg
+[license-url]: https://github.com/ashtuchkin/iconv-lite/blob/HEAD/LICENSE

backend/node_modules/mysql2/node_modules/iconv-lite/encodings/dbcs-codec.js

@@ -0,0 +1,532 @@
+"use strict"
+var Buffer = require("safer-buffer").Buffer
+
+// Multibyte codec. In this scheme, a character is represented by 1 or more bytes.
+// Our codec supports UTF-16 surrogates, extensions for GB18030 and unicode sequences.
+// To save memory and loading time, we read table files only when requested.
+
+exports._dbcs = DBCSCodec
+
+var UNASSIGNED = -1
+var GB18030_CODE = -2
+var SEQ_START = -10
+var NODE_START = -1000
+var UNASSIGNED_NODE = new Array(0x100)
+var DEF_CHAR = -1
+
+for (var i = 0; i < 0x100; i++) { UNASSIGNED_NODE[i] = UNASSIGNED }
+
+// Class DBCSCodec reads and initializes mapping tables.
+function DBCSCodec (codecOptions, iconv) {
+  this.encodingName = codecOptions.encodingName
+  if (!codecOptions) { throw new Error("DBCS codec is called without the data.") }
+  if (!codecOptions.table) { throw new Error("Encoding '" + this.encodingName + "' has no data.") }
+
+  // Load tables.
+  var mappingTable = codecOptions.table()
+
+  // Decode tables: MBCS -> Unicode.
+
+  // decodeTables is a trie, encoded as an array of arrays of integers. Internal arrays are trie nodes and all have len = 256.
+  // Trie root is decodeTables[0].
+  // Values: >=  0 -> unicode character code. can be > 0xFFFF
+  //         == UNASSIGNED -> unknown/unassigned sequence.
+  //         == GB18030_CODE -> this is the end of a GB18030 4-byte sequence.
+  //         <= NODE_START -> index of the next node in our trie to process next byte.
+  //         <= SEQ_START  -> index of the start of a character code sequence, in decodeTableSeq.
+  this.decodeTables = []
+  this.decodeTables[0] = UNASSIGNED_NODE.slice(0) // Create root node.
+
+  // Sometimes a MBCS char corresponds to a sequence of unicode chars. We store them as arrays of integers here.
+  this.decodeTableSeq = []
+
+  // Actual mapping tables consist of chunks. Use them to fill up decode tables.
+  for (var i = 0; i < mappingTable.length; i++) { this._addDecodeChunk(mappingTable[i]) }
+
+  // Load & create GB18030 tables when needed.
+  if (typeof codecOptions.gb18030 === "function") {
+    this.gb18030 = codecOptions.gb18030() // Load GB18030 ranges.
+
+    // Add GB18030 common decode nodes.
+    var commonThirdByteNodeIdx = this.decodeTables.length
+    this.decodeTables.push(UNASSIGNED_NODE.slice(0))
+
+    var commonFourthByteNodeIdx = this.decodeTables.length
+    this.decodeTables.push(UNASSIGNED_NODE.slice(0))
+
+    // Fill out the tree
+    var firstByteNode = this.decodeTables[0]
+    for (var i = 0x81; i <= 0xFE; i++) {
+      var secondByteNode = this.decodeTables[NODE_START - firstByteNode[i]]
+      for (var j = 0x30; j <= 0x39; j++) {
+        if (secondByteNode[j] === UNASSIGNED) {
+          secondByteNode[j] = NODE_START - commonThirdByteNodeIdx
+        } else if (secondByteNode[j] > NODE_START) {
+          throw new Error("gb18030 decode tables conflict at byte 2")
+        }
+
+        var thirdByteNode = this.decodeTables[NODE_START - secondByteNode[j]]
+        for (var k = 0x81; k <= 0xFE; k++) {
+          if (thirdByteNode[k] === UNASSIGNED) {
+            thirdByteNode[k] = NODE_START - commonFourthByteNodeIdx
+          } else if (thirdByteNode[k] === NODE_START - commonFourthByteNodeIdx) {
+            continue
+          } else if (thirdByteNode[k] > NODE_START) {
+            throw new Error("gb18030 decode tables conflict at byte 3")
+          }
+
+          var fourthByteNode = this.decodeTables[NODE_START - thirdByteNode[k]]
+          for (var l = 0x30; l <= 0x39; l++) {
+            if (fourthByteNode[l] === UNASSIGNED) { fourthByteNode[l] = GB18030_CODE }
+          }
+        }
+      }
+    }
+  }
+
+  this.defaultCharUnicode = iconv.defaultCharUnicode
+
+  // Encode tables: Unicode -> DBCS.
+
+  // `encodeTable` is array mapping from unicode char to encoded char. All its values are integers for performance.
+  // Because it can be sparse, it is represented as array of buckets by 256 chars each. Bucket can be null.
+  // Values: >=  0 -> it is a normal char. Write the value (if <=256 then 1 byte, if <=65536 then 2 bytes, etc.).
+  //         == UNASSIGNED -> no conversion found. Output a default char.
+  //         <= SEQ_START  -> it's an index in encodeTableSeq, see below. The character starts a sequence.
+  this.encodeTable = []
+
+  // `encodeTableSeq` is used when a sequence of unicode characters is encoded as a single code. We use a tree of
+  // objects where keys correspond to characters in sequence and leafs are the encoded dbcs values. A special DEF_CHAR key
+  // means end of sequence (needed when one sequence is a strict subsequence of another).
+  // Objects are kept separately from encodeTable to increase performance.
+  this.encodeTableSeq = []
+
+  // Some chars can be decoded, but need not be encoded.
+  var skipEncodeChars = {}
+  if (codecOptions.encodeSkipVals) {
+    for (var i = 0; i < codecOptions.encodeSkipVals.length; i++) {
+      var val = codecOptions.encodeSkipVals[i]
+      if (typeof val === "number") { skipEncodeChars[val] = true } else {
+        for (var j = val.from; j <= val.to; j++) { skipEncodeChars[j] = true }
+      }
+    }
+  }
+
+  // Use decode trie to recursively fill out encode tables.
+  this._fillEncodeTable(0, 0, skipEncodeChars)
+
+  // Add more encoding pairs when needed.
+  if (codecOptions.encodeAdd) {
+    for (var uChar in codecOptions.encodeAdd) {
+      if (Object.prototype.hasOwnProperty.call(codecOptions.encodeAdd, uChar)) { this._setEncodeChar(uChar.charCodeAt(0), codecOptions.encodeAdd[uChar]) }
+    }
+  }
+
+  this.defCharSB = this.encodeTable[0][iconv.defaultCharSingleByte.charCodeAt(0)]
+  if (this.defCharSB === UNASSIGNED) this.defCharSB = this.encodeTable[0]["?"]
+  if (this.defCharSB === UNASSIGNED) this.defCharSB = "?".charCodeAt(0)
+}
+
+DBCSCodec.prototype.encoder = DBCSEncoder
+DBCSCodec.prototype.decoder = DBCSDecoder
+
+// Decoder helpers
+DBCSCodec.prototype._getDecodeTrieNode = function (addr) {
+  var bytes = []
+  for (; addr > 0; addr >>>= 8) { bytes.push(addr & 0xFF) }
+  if (bytes.length == 0) { bytes.push(0) }
+
+  var node = this.decodeTables[0]
+  for (var i = bytes.length - 1; i > 0; i--) { // Traverse nodes deeper into the trie.
+    var val = node[bytes[i]]
+
+    if (val == UNASSIGNED) { // Create new node.
+      node[bytes[i]] = NODE_START - this.decodeTables.length
+      this.decodeTables.push(node = UNASSIGNED_NODE.slice(0))
+    } else if (val <= NODE_START) { // Existing node.
+      node = this.decodeTables[NODE_START - val]
+    } else { throw new Error("Overwrite byte in " + this.encodingName + ", addr: " + addr.toString(16)) }
+  }
+  return node
+}
+
+DBCSCodec.prototype._addDecodeChunk = function (chunk) {
+  // First element of chunk is the hex mbcs code where we start.
+  var curAddr = parseInt(chunk[0], 16)
+
+  // Choose the decoding node where we'll write our chars.
+  var writeTable = this._getDecodeTrieNode(curAddr)
+  curAddr = curAddr & 0xFF
+
+  // Write all other elements of the chunk to the table.
+  for (var k = 1; k < chunk.length; k++) {
+    var part = chunk[k]
+    if (typeof part === "string") { // String, write as-is.
+      for (var l = 0; l < part.length;) {
+        var code = part.charCodeAt(l++)
+        if (code >= 0xD800 && code < 0xDC00) { // Decode surrogate
+          var codeTrail = part.charCodeAt(l++)
+          if (codeTrail >= 0xDC00 && codeTrail < 0xE000) { writeTable[curAddr++] = 0x10000 + (code - 0xD800) * 0x400 + (codeTrail - 0xDC00) } else { throw new Error("Incorrect surrogate pair in " + this.encodingName + " at chunk " + chunk[0]) }
+        } else if (code > 0x0FF0 && code <= 0x0FFF) { // Character sequence (our own encoding used)
+          var len = 0xFFF - code + 2
+          var seq = []
+          for (var m = 0; m < len; m++) { seq.push(part.charCodeAt(l++)) } // Simple variation: don't support surrogates or subsequences in seq.
+
+          writeTable[curAddr++] = SEQ_START - this.decodeTableSeq.length
+          this.decodeTableSeq.push(seq)
+        } else { writeTable[curAddr++] = code } // Basic char
+      }
+    } else if (typeof part === "number") { // Integer, meaning increasing sequence starting with prev character.
+      var charCode = writeTable[curAddr - 1] + 1
+      for (var l = 0; l < part; l++) { writeTable[curAddr++] = charCode++ }
+    } else { throw new Error("Incorrect type '" + typeof part + "' given in " + this.encodingName + " at chunk " + chunk[0]) }
+  }
+  if (curAddr > 0xFF) { throw new Error("Incorrect chunk in " + this.encodingName + " at addr " + chunk[0] + ": too long" + curAddr) }
+}
+
+// Encoder helpers
+DBCSCodec.prototype._getEncodeBucket = function (uCode) {
+  var high = uCode >> 8 // This could be > 0xFF because of astral characters.
+  if (this.encodeTable[high] === undefined) {
+    this.encodeTable[high] = UNASSIGNED_NODE.slice(0)
+  } // Create bucket on demand.
+  return this.encodeTable[high]
+}
+
+DBCSCodec.prototype._setEncodeChar = function (uCode, dbcsCode) {
+  var bucket = this._getEncodeBucket(uCode)
+  var low = uCode & 0xFF
+  if (bucket[low] <= SEQ_START) { this.encodeTableSeq[SEQ_START - bucket[low]][DEF_CHAR] = dbcsCode } // There's already a sequence, set a single-char subsequence of it.
+  else if (bucket[low] == UNASSIGNED) { bucket[low] = dbcsCode }
+}
+
+DBCSCodec.prototype._setEncodeSequence = function (seq, dbcsCode) {
+  // Get the root of character tree according to first character of the sequence.
+  var uCode = seq[0]
+  var bucket = this._getEncodeBucket(uCode)
+  var low = uCode & 0xFF
+
+  var node
+  if (bucket[low] <= SEQ_START) {
+    // There's already a sequence with  - use it.
+    node = this.encodeTableSeq[SEQ_START - bucket[low]]
+  } else {
+    // There was no sequence object - allocate a new one.
+    node = {}
+    if (bucket[low] !== UNASSIGNED) node[DEF_CHAR] = bucket[low] // If a char was set before - make it a single-char subsequence.
+    bucket[low] = SEQ_START - this.encodeTableSeq.length
+    this.encodeTableSeq.push(node)
+  }
+
+  // Traverse the character tree, allocating new nodes as needed.
+  for (var j = 1; j < seq.length - 1; j++) {
+    var oldVal = node[uCode]
+    if (typeof oldVal === "object") { node = oldVal } else {
+      node = node[uCode] = {}
+      if (oldVal !== undefined) { node[DEF_CHAR] = oldVal }
+    }
+  }
+
+  // Set the leaf to given dbcsCode.
+  uCode = seq[seq.length - 1]
+  node[uCode] = dbcsCode
+}
+
+DBCSCodec.prototype._fillEncodeTable = function (nodeIdx, prefix, skipEncodeChars) {
+  var node = this.decodeTables[nodeIdx]
+  var hasValues = false
+  var subNodeEmpty = {}
+  for (var i = 0; i < 0x100; i++) {
+    var uCode = node[i]
+    var mbCode = prefix + i
+    if (skipEncodeChars[mbCode]) { continue }
+
+    if (uCode >= 0) {
+      this._setEncodeChar(uCode, mbCode)
+      hasValues = true
+    } else if (uCode <= NODE_START) {
+      var subNodeIdx = NODE_START - uCode
+      if (!subNodeEmpty[subNodeIdx]) {  // Skip empty subtrees (they are too large in gb18030).
+        var newPrefix = (mbCode << 8) >>> 0  // NOTE: '>>> 0' keeps 32-bit num positive.
+        if (this._fillEncodeTable(subNodeIdx, newPrefix, skipEncodeChars)) { hasValues = true } else { subNodeEmpty[subNodeIdx] = true }
+      }
+    } else if (uCode <= SEQ_START) {
+      this._setEncodeSequence(this.decodeTableSeq[SEQ_START - uCode], mbCode)
+      hasValues = true
+    }
+  }
+  return hasValues
+}
+
+// == Encoder ==================================================================
+
+function DBCSEncoder (options, codec) {
+  // Encoder state
+  this.leadSurrogate = -1
+  this.seqObj = undefined
+
+  // Static data
+  this.encodeTable = codec.encodeTable
+  this.encodeTableSeq = codec.encodeTableSeq
+  this.defaultCharSingleByte = codec.defCharSB
+  this.gb18030 = codec.gb18030
+}
+
+DBCSEncoder.prototype.write = function (str) {
+  var newBuf = Buffer.alloc(str.length * (this.gb18030 ? 4 : 3))
+  var leadSurrogate = this.leadSurrogate
+  var seqObj = this.seqObj
+  var nextChar = -1
+  var i = 0; var j = 0
+
+  while (true) {
+    // 0. Get next character.
+    if (nextChar === -1) {
+      if (i == str.length) break
+      var uCode = str.charCodeAt(i++)
+    } else {
+      var uCode = nextChar
+      nextChar = -1
+    }
+
+    // 1. Handle surrogates.
+    if (uCode >= 0xD800 && uCode < 0xE000) { // Char is one of surrogates.
+      if (uCode < 0xDC00) { // We've got lead surrogate.
+        if (leadSurrogate === -1) {
+          leadSurrogate = uCode
+          continue
+        } else {
+          leadSurrogate = uCode
+          // Double lead surrogate found.
+          uCode = UNASSIGNED
+        }
+      } else { // We've got trail surrogate.
+        if (leadSurrogate !== -1) {
+          uCode = 0x10000 + (leadSurrogate - 0xD800) * 0x400 + (uCode - 0xDC00)
+          leadSurrogate = -1
+        } else {
+          // Incomplete surrogate pair - only trail surrogate found.
+          uCode = UNASSIGNED
+        }
+      }
+    } else if (leadSurrogate !== -1) {
+      // Incomplete surrogate pair - only lead surrogate found.
+      nextChar = uCode; uCode = UNASSIGNED // Write an error, then current char.
+      leadSurrogate = -1
+    }
+
+    // 2. Convert uCode character.
+    var dbcsCode = UNASSIGNED
+    if (seqObj !== undefined && uCode != UNASSIGNED) { // We are in the middle of the sequence
+      var resCode = seqObj[uCode]
+      if (typeof resCode === "object") { // Sequence continues.
+        seqObj = resCode
+        continue
+      } else if (typeof resCode === "number") { // Sequence finished. Write it.
+        dbcsCode = resCode
+      } else if (resCode == undefined) { // Current character is not part of the sequence.
+        // Try default character for this sequence
+        resCode = seqObj[DEF_CHAR]
+        if (resCode !== undefined) {
+          dbcsCode = resCode // Found. Write it.
+          nextChar = uCode // Current character will be written too in the next iteration.
+        } else {
+          // TODO: What if we have no default? (resCode == undefined)
+          // Then, we should write first char of the sequence as-is and try the rest recursively.
+          // Didn't do it for now because no encoding has this situation yet.
+          // Currently, just skip the sequence and write current char.
+        }
+      }
+      seqObj = undefined
+    } else if (uCode >= 0) {  // Regular character
+      var subtable = this.encodeTable[uCode >> 8]
+      if (subtable !== undefined) { dbcsCode = subtable[uCode & 0xFF] }
+
+      if (dbcsCode <= SEQ_START) { // Sequence start
+        seqObj = this.encodeTableSeq[SEQ_START - dbcsCode]
+        continue
+      }
+
+      if (dbcsCode == UNASSIGNED && this.gb18030) {
+        // Use GB18030 algorithm to find character(s) to write.
+        var idx = findIdx(this.gb18030.uChars, uCode)
+        if (idx != -1) {
+          var dbcsCode = this.gb18030.gbChars[idx] + (uCode - this.gb18030.uChars[idx])
+          newBuf[j++] = 0x81 + Math.floor(dbcsCode / 12600); dbcsCode = dbcsCode % 12600
+          newBuf[j++] = 0x30 + Math.floor(dbcsCode / 1260); dbcsCode = dbcsCode % 1260
+          newBuf[j++] = 0x81 + Math.floor(dbcsCode / 10); dbcsCode = dbcsCode % 10
+          newBuf[j++] = 0x30 + dbcsCode
+          continue
+        }
+      }
+    }
+
+    // 3. Write dbcsCode character.
+    if (dbcsCode === UNASSIGNED) { dbcsCode = this.defaultCharSingleByte }
+
+    if (dbcsCode < 0x100) {
+      newBuf[j++] = dbcsCode
+    } else if (dbcsCode < 0x10000) {
+      newBuf[j++] = dbcsCode >> 8   // high byte
+      newBuf[j++] = dbcsCode & 0xFF // low byte
+    } else if (dbcsCode < 0x1000000) {
+      newBuf[j++] = dbcsCode >> 16
+      newBuf[j++] = (dbcsCode >> 8) & 0xFF
+      newBuf[j++] = dbcsCode & 0xFF
+    } else {
+      newBuf[j++] = dbcsCode >>> 24
+      newBuf[j++] = (dbcsCode >>> 16) & 0xFF
+      newBuf[j++] = (dbcsCode >>> 8) & 0xFF
+      newBuf[j++] = dbcsCode & 0xFF
+    }
+  }
+
+  this.seqObj = seqObj
+  this.leadSurrogate = leadSurrogate
+  return newBuf.slice(0, j)
+}
+
+DBCSEncoder.prototype.end = function () {
+  if (this.leadSurrogate === -1 && this.seqObj === undefined) { return } // All clean. Most often case.
+
+  var newBuf = Buffer.alloc(10); var j = 0
+
+  if (this.seqObj) { // We're in the sequence.
+    var dbcsCode = this.seqObj[DEF_CHAR]
+    if (dbcsCode !== undefined) { // Write beginning of the sequence.
+      if (dbcsCode < 0x100) {
+        newBuf[j++] = dbcsCode
+      } else {
+        newBuf[j++] = dbcsCode >> 8   // high byte
+        newBuf[j++] = dbcsCode & 0xFF // low byte
+      }
+    } else {
+      // See todo above.
+    }
+    this.seqObj = undefined
+  }
+
+  if (this.leadSurrogate !== -1) {
+    // Incomplete surrogate pair - only lead surrogate found.
+    newBuf[j++] = this.defaultCharSingleByte
+    this.leadSurrogate = -1
+  }
+
+  return newBuf.slice(0, j)
+}
+
+// Export for testing
+DBCSEncoder.prototype.findIdx = findIdx
+
+// == Decoder ==================================================================
+
+function DBCSDecoder (options, codec) {
+  // Decoder state
+  this.nodeIdx = 0
+  this.prevBytes = []
+
+  // Static data
+  this.decodeTables = codec.decodeTables
+  this.decodeTableSeq = codec.decodeTableSeq
+  this.defaultCharUnicode = codec.defaultCharUnicode
+  this.gb18030 = codec.gb18030
+}
+
+DBCSDecoder.prototype.write = function (buf) {
+  var newBuf = Buffer.alloc(buf.length * 2)
+  var nodeIdx = this.nodeIdx
+  var prevBytes = this.prevBytes; var prevOffset = this.prevBytes.length
+  var seqStart = -this.prevBytes.length // idx of the start of current parsed sequence.
+  var uCode
+
+  for (var i = 0, j = 0; i < buf.length; i++) {
+    var curByte = (i >= 0) ? buf[i] : prevBytes[i + prevOffset]
+
+    // Lookup in current trie node.
+    var uCode = this.decodeTables[nodeIdx][curByte]
+
+    if (uCode >= 0) {
+      // Normal character, just use it.
+    } else if (uCode === UNASSIGNED) { // Unknown char.
+      // TODO: Callback with seq.
+      uCode = this.defaultCharUnicode.charCodeAt(0)
+      i = seqStart // Skip one byte ('i' will be incremented by the for loop) and try to parse again.
+    } else if (uCode === GB18030_CODE) {
+      if (i >= 3) {
+        var ptr = (buf[i - 3] - 0x81) * 12600 + (buf[i - 2] - 0x30) * 1260 + (buf[i - 1] - 0x81) * 10 + (curByte - 0x30)
+      } else {
+        var ptr = (prevBytes[i - 3 + prevOffset] - 0x81) * 12600 +
+                          (((i - 2 >= 0) ? buf[i - 2] : prevBytes[i - 2 + prevOffset]) - 0x30) * 1260 +
+                          (((i - 1 >= 0) ? buf[i - 1] : prevBytes[i - 1 + prevOffset]) - 0x81) * 10 +
+                          (curByte - 0x30)
+      }
+      var idx = findIdx(this.gb18030.gbChars, ptr)
+      uCode = this.gb18030.uChars[idx] + ptr - this.gb18030.gbChars[idx]
+    } else if (uCode <= NODE_START) { // Go to next trie node.
+      nodeIdx = NODE_START - uCode
+      continue
+    } else if (uCode <= SEQ_START) { // Output a sequence of chars.
+      var seq = this.decodeTableSeq[SEQ_START - uCode]
+      for (var k = 0; k < seq.length - 1; k++) {
+        uCode = seq[k]
+        newBuf[j++] = uCode & 0xFF
+        newBuf[j++] = uCode >> 8
+      }
+      uCode = seq[seq.length - 1]
+    } else { throw new Error("iconv-lite internal error: invalid decoding table value " + uCode + " at " + nodeIdx + "/" + curByte) }
+
+    // Write the character to buffer, handling higher planes using surrogate pair.
+    if (uCode >= 0x10000) {
+      uCode -= 0x10000
+      var uCodeLead = 0xD800 | (uCode >> 10)
+      newBuf[j++] = uCodeLead & 0xFF
+      newBuf[j++] = uCodeLead >> 8
+
+      uCode = 0xDC00 | (uCode & 0x3FF)
+    }
+    newBuf[j++] = uCode & 0xFF
+    newBuf[j++] = uCode >> 8
+
+    // Reset trie node.
+    nodeIdx = 0; seqStart = i + 1
+  }
+
+  this.nodeIdx = nodeIdx
+  this.prevBytes = (seqStart >= 0)
+    ? Array.prototype.slice.call(buf, seqStart)
+    : prevBytes.slice(seqStart + prevOffset).concat(Array.prototype.slice.call(buf))
+
+  return newBuf.slice(0, j).toString("ucs2")
+}
+
+DBCSDecoder.prototype.end = function () {
+  var ret = ""
+
+  // Try to parse all remaining chars.
+  while (this.prevBytes.length > 0) {
+    // Skip 1 character in the buffer.
+    ret += this.defaultCharUnicode
+    var bytesArr = this.prevBytes.slice(1)
+
+    // Parse remaining as usual.
+    this.prevBytes = []
+    this.nodeIdx = 0
+    if (bytesArr.length > 0) { ret += this.write(bytesArr) }
+  }
+
+  this.prevBytes = []
+  this.nodeIdx = 0
+  return ret
+}
+
+// Binary search for GB18030. Returns largest i such that table[i] <= val.
+function findIdx (table, val) {
+  if (table[0] > val) { return -1 }
+
+  var l = 0; var r = table.length
+  while (l < r - 1) { // always table[l] <= val < table[r]
+    var mid = l + ((r - l + 1) >> 1)
+    if (table[mid] <= val) { l = mid } else { r = mid }
+  }
+  return l
+}

backend/node_modules/mysql2/node_modules/iconv-lite/encodings/dbcs-data.js

@@ -0,0 +1,185 @@
+"use strict"
+
+// Description of supported double byte encodings and aliases.
+// Tables are not require()-d until they are needed to speed up library load.
+// require()-s are direct to support Browserify.
+
+module.exports = {
+
+  // == Japanese/ShiftJIS ====================================================
+  // All japanese encodings are based on JIS X set of standards:
+  // JIS X 0201 - Single-byte encoding of ASCII + ¥ + Kana chars at 0xA1-0xDF.
+  // JIS X 0208 - Main set of 6879 characters, placed in 94x94 plane, to be encoded by 2 bytes.
+  //              Has several variations in 1978, 1983, 1990 and 1997.
+  // JIS X 0212 - Supplementary plane of 6067 chars in 94x94 plane. 1990. Effectively dead.
+  // JIS X 0213 - Extension and modern replacement of 0208 and 0212. Total chars: 11233.
+  //              2 planes, first is superset of 0208, second - revised 0212.
+  //              Introduced in 2000, revised 2004. Some characters are in Unicode Plane 2 (0x2xxxx)
+
+  // Byte encodings are:
+  //  * Shift_JIS: Compatible with 0201, uses not defined chars in top half as lead bytes for double-byte
+  //               encoding of 0208. Lead byte ranges: 0x81-0x9F, 0xE0-0xEF; Trail byte ranges: 0x40-0x7E, 0x80-0x9E, 0x9F-0xFC.
+  //               Windows CP932 is a superset of Shift_JIS. Some companies added more chars, notably KDDI.
+  //  * EUC-JP:    Up to 3 bytes per character. Used mostly on *nixes.
+  //               0x00-0x7F       - lower part of 0201
+  //               0x8E, 0xA1-0xDF - upper part of 0201
+  //               (0xA1-0xFE)x2   - 0208 plane (94x94).
+  //               0x8F, (0xA1-0xFE)x2 - 0212 plane (94x94).
+  //  * JIS X 208: 7-bit, direct encoding of 0208. Byte ranges: 0x21-0x7E (94 values). Uncommon.
+  //               Used as-is in ISO2022 family.
+  //  * ISO2022-JP: Stateful encoding, with escape sequences to switch between ASCII,
+  //                0201-1976 Roman, 0208-1978, 0208-1983.
+  //  * ISO2022-JP-1: Adds esc seq for 0212-1990.
+  //  * ISO2022-JP-2: Adds esc seq for GB2313-1980, KSX1001-1992, ISO8859-1, ISO8859-7.
+  //  * ISO2022-JP-3: Adds esc seq for 0201-1976 Kana set, 0213-2000 Planes 1, 2.
+  //  * ISO2022-JP-2004: Adds 0213-2004 Plane 1.
+  //
+  // After JIS X 0213 appeared, Shift_JIS-2004, EUC-JISX0213 and ISO2022-JP-2004 followed, with just changing the planes.
+  //
+  // Overall, it seems that it's a mess :( http://www8.plala.or.jp/tkubota1/unicode-symbols-map2.html
+
+  shiftjis: {
+    type: "_dbcs",
+    table: function () { return require("./tables/shiftjis.json") },
+    encodeAdd: { "\u00a5": 0x5C, "\u203E": 0x7E },
+    encodeSkipVals: [{ from: 0xED40, to: 0xF940 }]
+  },
+  csshiftjis: "shiftjis",
+  mskanji: "shiftjis",
+  sjis: "shiftjis",
+  windows31j: "shiftjis",
+  ms31j: "shiftjis",
+  xsjis: "shiftjis",
+  windows932: "shiftjis",
+  ms932: "shiftjis",
+  932: "shiftjis",
+  cp932: "shiftjis",
+
+  eucjp: {
+    type: "_dbcs",
+    table: function () { return require("./tables/eucjp.json") },
+    encodeAdd: { "\u00a5": 0x5C, "\u203E": 0x7E }
+  },
+
+  // TODO: KDDI extension to Shift_JIS
+  // TODO: IBM CCSID 942 = CP932, but F0-F9 custom chars and other char changes.
+  // TODO: IBM CCSID 943 = Shift_JIS = CP932 with original Shift_JIS lower 128 chars.
+
+  // == Chinese/GBK ==========================================================
+  // http://en.wikipedia.org/wiki/GBK
+  // We mostly implement W3C recommendation: https://www.w3.org/TR/encoding/#gbk-encoder
+
+  // Oldest GB2312 (1981, ~7600 chars) is a subset of CP936
+  gb2312: "cp936",
+  gb231280: "cp936",
+  gb23121980: "cp936",
+  csgb2312: "cp936",
+  csiso58gb231280: "cp936",
+  euccn: "cp936",
+
+  // Microsoft's CP936 is a subset and approximation of GBK.
+  windows936: "cp936",
+  ms936: "cp936",
+  936: "cp936",
+  cp936: {
+    type: "_dbcs",
+    table: function () { return require("./tables/cp936.json") }
+  },
+
+  // GBK (~22000 chars) is an extension of CP936 that added user-mapped chars and some other.
+  gbk: {
+    type: "_dbcs",
+    table: function () { return require("./tables/cp936.json").concat(require("./tables/gbk-added.json")) }
+  },
+  xgbk: "gbk",
+  isoir58: "gbk",
+
+  // GB18030 is an algorithmic extension of GBK.
+  // Main source: https://www.w3.org/TR/encoding/#gbk-encoder
+  // http://icu-project.org/docs/papers/gb18030.html
+  // http://source.icu-project.org/repos/icu/data/trunk/charset/data/xml/gb-18030-2000.xml
+  // http://www.khngai.com/chinese/charmap/tblgbk.php?page=0
+  gb18030: {
+    type: "_dbcs",
+    table: function () { return require("./tables/cp936.json").concat(require("./tables/gbk-added.json")) },
+    gb18030: function () { return require("./tables/gb18030-ranges.json") },
+    encodeSkipVals: [0x80],
+    encodeAdd: { "€": 0xA2E3 }
+  },
+
+  chinese: "gb18030",
+
+  // == Korean ===============================================================
+  // EUC-KR, KS_C_5601 and KS X 1001 are exactly the same.
+  windows949: "cp949",
+  ms949: "cp949",
+  949: "cp949",
+  cp949: {
+    type: "_dbcs",
+    table: function () { return require("./tables/cp949.json") }
+  },
+
+  cseuckr: "cp949",
+  csksc56011987: "cp949",
+  euckr: "cp949",
+  isoir149: "cp949",
+  korean: "cp949",
+  ksc56011987: "cp949",
+  ksc56011989: "cp949",
+  ksc5601: "cp949",
+
+  // == Big5/Taiwan/Hong Kong ================================================
+  // There are lots of tables for Big5 and cp950. Please see the following links for history:
+  // http://moztw.org/docs/big5/  http://www.haible.de/bruno/charsets/conversion-tables/Big5.html
+  // Variations, in roughly number of defined chars:
+  //  * Windows CP 950: Microsoft variant of Big5. Canonical: http://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WINDOWS/CP950.TXT
+  //  * Windows CP 951: Microsoft variant of Big5-HKSCS-2001. Seems to be never public. http://me.abelcheung.org/articles/research/what-is-cp951/
+  //  * Big5-2003 (Taiwan standard) almost superset of cp950.
+  //  * Unicode-at-on (UAO) / Mozilla 1.8. Falling out of use on the Web. Not supported by other browsers.
+  //  * Big5-HKSCS (-2001, -2004, -2008). Hong Kong standard.
+  //    many unicode code points moved from PUA to Supplementary plane (U+2XXXX) over the years.
+  //    Plus, it has 4 combining sequences.
+  //    Seems that Mozilla refused to support it for 10 yrs. https://bugzilla.mozilla.org/show_bug.cgi?id=162431 https://bugzilla.mozilla.org/show_bug.cgi?id=310299
+  //    because big5-hkscs is the only encoding to include astral characters in non-algorithmic way.
+  //    Implementations are not consistent within browsers; sometimes labeled as just big5.
+  //    MS Internet Explorer switches from big5 to big5-hkscs when a patch applied.
+  //    Great discussion & recap of what's going on https://bugzilla.mozilla.org/show_bug.cgi?id=912470#c31
+  //    In the encoder, it might make sense to support encoding old PUA mappings to Big5 bytes seq-s.
+  //    Official spec: http://www.ogcio.gov.hk/en/business/tech_promotion/ccli/terms/doc/2003cmp_2008.txt
+  //                   http://www.ogcio.gov.hk/tc/business/tech_promotion/ccli/terms/doc/hkscs-2008-big5-iso.txt
+  //
+  // Current understanding of how to deal with Big5(-HKSCS) is in the Encoding Standard, http://encoding.spec.whatwg.org/#big5-encoder
+  // Unicode mapping (http://www.unicode.org/Public/MAPPINGS/OBSOLETE/EASTASIA/OTHER/BIG5.TXT) is said to be wrong.
+
+  windows950: "cp950",
+  ms950: "cp950",
+  950: "cp950",
+  cp950: {
+    type: "_dbcs",
+    table: function () { return require("./tables/cp950.json") }
+  },
+
+  // Big5 has many variations and is an extension of cp950. We use Encoding Standard's as a consensus.
+  big5: "big5hkscs",
+  big5hkscs: {
+    type: "_dbcs",
+    table: function () { return require("./tables/cp950.json").concat(require("./tables/big5-added.json")) },
+    encodeSkipVals: [
+      // Although Encoding Standard says we should avoid encoding to HKSCS area (See Step 1 of
+      // https://encoding.spec.whatwg.org/#index-big5-pointer), we still do it to increase compatibility with ICU.
+      // But if a single unicode point can be encoded both as HKSCS and regular Big5, we prefer the latter.
+      0x8e69, 0x8e6f, 0x8e7e, 0x8eab, 0x8eb4, 0x8ecd, 0x8ed0, 0x8f57, 0x8f69, 0x8f6e, 0x8fcb, 0x8ffe,
+      0x906d, 0x907a, 0x90c4, 0x90dc, 0x90f1, 0x91bf, 0x92af, 0x92b0, 0x92b1, 0x92b2, 0x92d1, 0x9447, 0x94ca,
+      0x95d9, 0x96fc, 0x9975, 0x9b76, 0x9b78, 0x9b7b, 0x9bc6, 0x9bde, 0x9bec, 0x9bf6, 0x9c42, 0x9c53, 0x9c62,
+      0x9c68, 0x9c6b, 0x9c77, 0x9cbc, 0x9cbd, 0x9cd0, 0x9d57, 0x9d5a, 0x9dc4, 0x9def, 0x9dfb, 0x9ea9, 0x9eef,
+      0x9efd, 0x9f60, 0x9fcb, 0xa077, 0xa0dc, 0xa0df, 0x8fcc, 0x92c8, 0x9644, 0x96ed,
+
+      // Step 2 of https://encoding.spec.whatwg.org/#index-big5-pointer: Use last pointer for U+2550, U+255E, U+2561, U+256A, U+5341, or U+5345
+      0xa2a4, 0xa2a5, 0xa2a7, 0xa2a6, 0xa2cc, 0xa2ce
+    ]
+  },
+
+  cnbig5: "big5hkscs",
+  csbig5: "big5hkscs",
+  xxbig5: "big5hkscs"
+}

backend/node_modules/mysql2/node_modules/iconv-lite/encodings/index.js

@@ -0,0 +1,23 @@
+"use strict"
+
+var mergeModules = require("../lib/helpers/merge-exports")
+
+// Update this array if you add/rename/remove files in this directory.
+// We support Browserify by skipping automatic module discovery and requiring modules directly.
+var modules = [
+  require("./internal"),
+  require("./utf32"),
+  require("./utf16"),
+  require("./utf7"),
+  require("./sbcs-codec"),
+  require("./sbcs-data"),
+  require("./sbcs-data-generated"),
+  require("./dbcs-codec"),
+  require("./dbcs-data")
+]
+
+// Put all encoding/alias/codec definitions to single object and export it.
+for (var i = 0; i < modules.length; i++) {
+  var module = modules[i]
+  mergeModules(exports, module)
+}

backend/node_modules/mysql2/node_modules/iconv-lite/encodings/internal.js

@@ -0,0 +1,218 @@
+"use strict"
+var Buffer = require("safer-buffer").Buffer
+
+// Export Node.js internal encodings.
+
+module.exports = {
+  // Encodings
+  utf8: { type: "_internal", bomAware: true },
+  cesu8: { type: "_internal", bomAware: true },
+  unicode11utf8: "utf8",
+
+  ucs2: { type: "_internal", bomAware: true },
+  utf16le: "ucs2",
+
+  binary: { type: "_internal" },
+  base64: { type: "_internal" },
+  hex: { type: "_internal" },
+
+  // Codec.
+  _internal: InternalCodec
+}
+
+// ------------------------------------------------------------------------------
+
+function InternalCodec (codecOptions, iconv) {
+  this.enc = codecOptions.encodingName
+  this.bomAware = codecOptions.bomAware
+
+  if (this.enc === "base64") { this.encoder = InternalEncoderBase64 } else if (this.enc === "utf8") { this.encoder = InternalEncoderUtf8 } else if (this.enc === "cesu8") {
+    this.enc = "utf8" // Use utf8 for decoding.
+    this.encoder = InternalEncoderCesu8
+
+    // Add decoder for versions of Node not supporting CESU-8
+    if (Buffer.from("eda0bdedb2a9", "hex").toString() !== "💩") {
+      this.decoder = InternalDecoderCesu8
+      this.defaultCharUnicode = iconv.defaultCharUnicode
+    }
+  }
+}
+
+InternalCodec.prototype.encoder = InternalEncoder
+InternalCodec.prototype.decoder = InternalDecoder
+
+// ------------------------------------------------------------------------------
+
+// We use node.js internal decoder. Its signature is the same as ours.
+var StringDecoder = require("string_decoder").StringDecoder
+
+function InternalDecoder (options, codec) {
+  this.decoder = new StringDecoder(codec.enc)
+}
+
+InternalDecoder.prototype.write = function (buf) {
+  if (!Buffer.isBuffer(buf)) {
+    buf = Buffer.from(buf)
+  }
+
+  return this.decoder.write(buf)
+}
+
+InternalDecoder.prototype.end = function () {
+  return this.decoder.end()
+}
+
+// ------------------------------------------------------------------------------
+// Encoder is mostly trivial
+
+function InternalEncoder (options, codec) {
+  this.enc = codec.enc
+}
+
+InternalEncoder.prototype.write = function (str) {
+  return Buffer.from(str, this.enc)
+}
+
+InternalEncoder.prototype.end = function () {
+}
+
+// ------------------------------------------------------------------------------
+// Except base64 encoder, which must keep its state.
+
+function InternalEncoderBase64 (options, codec) {
+  this.prevStr = ""
+}
+
+InternalEncoderBase64.prototype.write = function (str) {
+  str = this.prevStr + str
+  var completeQuads = str.length - (str.length % 4)
+  this.prevStr = str.slice(completeQuads)
+  str = str.slice(0, completeQuads)
+
+  return Buffer.from(str, "base64")
+}
+
+InternalEncoderBase64.prototype.end = function () {
+  return Buffer.from(this.prevStr, "base64")
+}
+
+// ------------------------------------------------------------------------------
+// CESU-8 encoder is also special.
+
+function InternalEncoderCesu8 (options, codec) {
+}
+
+InternalEncoderCesu8.prototype.write = function (str) {
+  var buf = Buffer.alloc(str.length * 3); var bufIdx = 0
+  for (var i = 0; i < str.length; i++) {
+    var charCode = str.charCodeAt(i)
+    // Naive implementation, but it works because CESU-8 is especially easy
+    // to convert from UTF-16 (which all JS strings are encoded in).
+    if (charCode < 0x80) { buf[bufIdx++] = charCode } else if (charCode < 0x800) {
+      buf[bufIdx++] = 0xC0 + (charCode >>> 6)
+      buf[bufIdx++] = 0x80 + (charCode & 0x3f)
+    } else { // charCode will always be < 0x10000 in javascript.
+      buf[bufIdx++] = 0xE0 + (charCode >>> 12)
+      buf[bufIdx++] = 0x80 + ((charCode >>> 6) & 0x3f)
+      buf[bufIdx++] = 0x80 + (charCode & 0x3f)
+    }
+  }
+  return buf.slice(0, bufIdx)
+}
+
+InternalEncoderCesu8.prototype.end = function () {
+}
+
+// ------------------------------------------------------------------------------
+// CESU-8 decoder is not implemented in Node v4.0+
+
+function InternalDecoderCesu8 (options, codec) {
+  this.acc = 0
+  this.contBytes = 0
+  this.accBytes = 0
+  this.defaultCharUnicode = codec.defaultCharUnicode
+}
+
+InternalDecoderCesu8.prototype.write = function (buf) {
+  var acc = this.acc; var contBytes = this.contBytes; var accBytes = this.accBytes
+  var res = ""
+  for (var i = 0; i < buf.length; i++) {
+    var curByte = buf[i]
+    if ((curByte & 0xC0) !== 0x80) { // Leading byte
+      if (contBytes > 0) { // Previous code is invalid
+        res += this.defaultCharUnicode
+        contBytes = 0
+      }
+
+      if (curByte < 0x80) { // Single-byte code
+        res += String.fromCharCode(curByte)
+      } else if (curByte < 0xE0) { // Two-byte code
+        acc = curByte & 0x1F
+        contBytes = 1; accBytes = 1
+      } else if (curByte < 0xF0) { // Three-byte code
+        acc = curByte & 0x0F
+        contBytes = 2; accBytes = 1
+      } else { // Four or more are not supported for CESU-8.
+        res += this.defaultCharUnicode
+      }
+    } else { // Continuation byte
+      if (contBytes > 0) { // We're waiting for it.
+        acc = (acc << 6) | (curByte & 0x3f)
+        contBytes--; accBytes++
+        if (contBytes === 0) {
+          // Check for overlong encoding, but support Modified UTF-8 (encoding NULL as C0 80)
+          if (accBytes === 2 && acc < 0x80 && acc > 0) {
+            res += this.defaultCharUnicode
+          } else if (accBytes === 3 && acc < 0x800) {
+            res += this.defaultCharUnicode
+          } else {
+            // Actually add character.
+            res += String.fromCharCode(acc)
+          }
+        }
+      } else { // Unexpected continuation byte
+        res += this.defaultCharUnicode
+      }
+    }
+  }
+  this.acc = acc; this.contBytes = contBytes; this.accBytes = accBytes
+  return res
+}
+
+InternalDecoderCesu8.prototype.end = function () {
+  var res = 0
+  if (this.contBytes > 0) { res += this.defaultCharUnicode }
+  return res
+}
+
+// ------------------------------------------------------------------------------
+// check the chunk boundaries for surrogate pair
+
+function InternalEncoderUtf8 (options, codec) {
+  this.highSurrogate = ""
+}
+
+InternalEncoderUtf8.prototype.write = function (str) {
+  if (this.highSurrogate) {
+    str = this.highSurrogate + str
+    this.highSurrogate = ""
+  }
+
+  if (str.length > 0) {
+    var charCode = str.charCodeAt(str.length - 1)
+    if (charCode >= 0xd800 && charCode < 0xdc00) {
+      this.highSurrogate = str[str.length - 1]
+      str = str.slice(0, str.length - 1)
+    }
+  }
+
+  return Buffer.from(str, this.enc)
+}
+
+InternalEncoderUtf8.prototype.end = function () {
+  if (this.highSurrogate) {
+    var str = this.highSurrogate
+    this.highSurrogate = ""
+    return Buffer.from(str, this.enc)
+  }
+}

backend/node_modules/mysql2/node_modules/iconv-lite/encodings/sbcs-codec.js

@@ -0,0 +1,75 @@
+"use strict"
+var Buffer = require("safer-buffer").Buffer
+
+// Single-byte codec. Needs a 'chars' string parameter that contains 256 or 128 chars that
+// correspond to encoded bytes (if 128 - then lower half is ASCII).
+
+exports._sbcs = SBCSCodec
+function SBCSCodec (codecOptions, iconv) {
+  if (!codecOptions) {
+    throw new Error("SBCS codec is called without the data.")
+  }
+
+  // Prepare char buffer for decoding.
+  if (!codecOptions.chars || (codecOptions.chars.length !== 128 && codecOptions.chars.length !== 256)) {
+    throw new Error("Encoding '" + codecOptions.type + "' has incorrect 'chars' (must be of len 128 or 256)")
+  }
+
+  if (codecOptions.chars.length === 128) {
+    var asciiString = ""
+    for (var i = 0; i < 128; i++) {
+      asciiString += String.fromCharCode(i)
+    }
+    codecOptions.chars = asciiString + codecOptions.chars
+  }
+
+  this.decodeBuf = Buffer.from(codecOptions.chars, "ucs2")
+
+  // Encoding buffer.
+  var encodeBuf = Buffer.alloc(65536, iconv.defaultCharSingleByte.charCodeAt(0))
+
+  for (var i = 0; i < codecOptions.chars.length; i++) {
+    encodeBuf[codecOptions.chars.charCodeAt(i)] = i
+  }
+
+  this.encodeBuf = encodeBuf
+}
+
+SBCSCodec.prototype.encoder = SBCSEncoder
+SBCSCodec.prototype.decoder = SBCSDecoder
+
+function SBCSEncoder (options, codec) {
+  this.encodeBuf = codec.encodeBuf
+}
+
+SBCSEncoder.prototype.write = function (str) {
+  var buf = Buffer.alloc(str.length)
+  for (var i = 0; i < str.length; i++) {
+    buf[i] = this.encodeBuf[str.charCodeAt(i)]
+  }
+
+  return buf
+}
+
+SBCSEncoder.prototype.end = function () {
+}
+
+function SBCSDecoder (options, codec) {
+  this.decodeBuf = codec.decodeBuf
+}
+
+SBCSDecoder.prototype.write = function (buf) {
+  // Strings are immutable in JS -> we use ucs2 buffer to speed up computations.
+  var decodeBuf = this.decodeBuf
+  var newBuf = Buffer.alloc(buf.length * 2)
+  var idx1 = 0; var idx2 = 0
+  for (var i = 0; i < buf.length; i++) {
+    idx1 = buf[i] * 2; idx2 = i * 2
+    newBuf[idx2] = decodeBuf[idx1]
+    newBuf[idx2 + 1] = decodeBuf[idx1 + 1]
+  }
+  return newBuf.toString("ucs2")
+}
+
+SBCSDecoder.prototype.end = function () {
+}