ES6 refactor: dialects / MSSQL (#6049)

* ES6 refactor of MSSQL ConnectionManager

classes, let, const, arrow functions, export default

* Make Mssql Query an ES6 class

* ES6 refactor of Mssql Query

let, const, arrow functions, property shorthands, for of, export default

lib/dialects/mssql/connection-manager.js

 'use strict';
 
-var AbstractConnectionManager = require('../abstract/connection-manager')
-  , ConnectionManager
-  , ResourceLock = require('./resource-lock')
-  , Utils = require('../../utils')
-  , Promise = require('../../promise')
-  , sequelizeErrors = require('../../errors')
-  , parserStore = require('../parserStore')('mssql')
-  , _ = require('lodash');
-
-ConnectionManager = function(dialect, sequelize) {
-  AbstractConnectionManager.call(this, dialect, sequelize);
+const AbstractConnectionManager = require('../abstract/connection-manager');
+const ResourceLock = require('./resource-lock');
+const Promise = require('../../promise');
+const sequelizeErrors = require('../../errors');
+const parserStore = require('../parserStore')('mssql');
+const _ = require('lodash');
+
+class ConnectionManager extends AbstractConnectionManager {
+  constructor(dialect, sequelize) {
+    super(dialect, sequelize);
 
     this.sequelize = sequelize;
     this.sequelize.config.port = this.sequelize.config.port || 1433;
@@ -22,24 +21,20 @@ ConnectionManager = function(dialect, sequelize) {
       }
       throw err;
     }
-};
-
-Utils._.extend(ConnectionManager.prototype, AbstractConnectionManager.prototype);
-
+  }
 
-// Expose this as a method so that the parsing may be updated when the user has added additional, custom types
-ConnectionManager.prototype.$refreshTypeParser = function (dataType) {
+  // Expose this as a method so that the parsing may be updated when the user has added additional, custom types
+  $refreshTypeParser(dataType) {
     parserStore.refresh(dataType);
-};
+  }
 
-ConnectionManager.prototype.$clearTypeParser = function () {
+  $clearTypeParser() {
     parserStore.clear();
-};
+  }
 
-ConnectionManager.prototype.connect = function(config) {
-  var self = this;
-  return new Promise(function (resolve, reject) {
-    var connectionConfig = {
+  connect(config) {
+    return new Promise((resolve, reject) => {
+      const connectionConfig = {
         userName: config.username,
         password: config.password,
         server: config.host,
@@ -60,16 +55,16 @@ ConnectionManager.prototype.connect = function(config) {
           connectionConfig.domain = config.dialectOptions.domain;
         }
 
-      Object.keys(config.dialectOptions).forEach(function(key) {
+        for (const key of Object.keys(config.dialectOptions)) {
           connectionConfig.options[key] = config.dialectOptions[key];
-      });
+        }
       }
 
-    var connection = new self.lib.Connection(connectionConfig)
-      , connectionLock = new ResourceLock(connection);
-    connection.lib = self.lib;
+      const connection = new this.lib.Connection(connectionConfig);
+      const connectionLock = new ResourceLock(connection);
+      connection.lib = this.lib;
 
-    connection.on('connect', function(err) {
+      connection.on('connect', err => {
         if (!err) {
           resolve(connectionLock);
           return;
@@ -112,36 +107,39 @@ ConnectionManager.prototype.connect = function(config) {
       });
 
       if (config.pool.handleDisconnects) {
-      connection.on('error', function (err) {
+        connection.on('error', err => {
           switch (err.code) {
             case 'ESOCKET':
             case 'ECONNRESET':
-          self.pool.destroy(connectionLock);
+              this.pool.destroy(connectionLock);
           }
         });
       }
 
     });
-};
+  }
 
-ConnectionManager.prototype.disconnect = function(connectionLock) {
-  var connection = connectionLock.unwrap();
+  disconnect(connectionLock) {
+    const connection = connectionLock.unwrap();
 
     // Dont disconnect a connection that is already disconnected
     if (!!connection.closed) {
       return Promise.resolve();
     }
 
-  return new Promise(function (resolve, reject) {
+    return new Promise(resolve => {
       connection.on('end', resolve);
       connection.close();
     });
-};
+  }
 
-ConnectionManager.prototype.validate = function(connectionLock) {
-  var connection = connectionLock.unwrap();
+  validate(connectionLock) {
+    const connection = connectionLock.unwrap();
 
     return connection && connection.loggedIn;
-};
+  }
+}
 
 module.exports = ConnectionManager;
+module.exports.ConnectionManager = ConnectionManager;
+module.exports.default = ConnectionManager;