refactor: split common.js into lib modules

The proposal to put common.js into lib was good, but it felt
weird to arbitrarily stuff just some exported functions in
lib/common.js. This made sense when common.js was meant
to provide commons for index.js and promise.js. But
in the lib, this felt like a weird scope.

I therefore split common.js into

- lib/create_connection.js
- lib/create_pool.js
- lib/create_pool_cluster.js

Also made `require` more consistent in all affected files: all
`require` files now have a js suffix when they refer to a
single local file.

index.js

@@ -3,23 +3,25 @@
 const SqlString = require('sqlstring');
 
 const ConnectionConfig = require('./lib/connection_config.js');
-const parserCache = require('./lib/parsers/parser_cache');
+const parserCache = require('./lib/parsers/parser_cache.js');
 
-const common = require('./common');
-exports.createConnection = common.createConnection
+const Connection = require('./lib/connection.js');
 
+exports.createConnection = require('./lib/create_connection.js');
 exports.connect = exports.createConnection;
-exports.Connection = common.Connection;
+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 = common.createPool
+exports.createPool = createPool
 
-exports.createPoolCluster = common.createPoolCluster;
+exports.createPoolCluster = createPoolCluster;
 
-exports.createQuery = common.Connection.createQuery;
+exports.createQuery = Connection.createQuery;
 
 exports.Pool = Pool;
 
@@ -34,7 +36,7 @@ exports.createServer = function(handler) {
   return s;
 };
 
-exports.PoolConnection = require('./lib/pool_connection');
+exports.PoolConnection = require('./lib/pool_connection.js');
 exports.authPlugins = require('./lib/auth_plugins');
 exports.escape = SqlString.escape;
 exports.escapeId = SqlString.escapeId;

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;

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

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;

package.json

@@ -43,7 +43,6 @@
     "typings/mysql",
     "index.js",
     "index.d.ts",
-    "common.js",
     "promise.js",
     "promise.d.ts"
   ],

promise.js

@@ -1,12 +1,15 @@
 'use strict';
 
 const SqlString = require('sqlstring');
-const common = require('./common.js');
 const EventEmitter = require('events').EventEmitter;
 const parserCache = require('./lib/parsers/parser_cache.js');
 const PoolConnection = require('./lib/pool_connection.js');
 const Pool = require('./lib/pool.js');
 const PoolCluster = require('./lib/pool_cluster.js');
+const createConnection = require('./lib/create_connection.js');
+const Connection = require('./lib/connection.js');
+const createPool = require('./lib/create_pool.js');
+const createPoolCluster = require('./lib/create_pool_cluster.js');
 
 function makeDoneCb(resolve, reject, localErr) {
   return function (err, rows, fields) {
@@ -252,8 +255,8 @@ class PromiseConnection extends EventEmitter {
   }
 }
 
-function createConnection(opts) {
-  const coreConnection = common.createConnection(opts);
+function createConnectionPromise(opts) {
+  const coreConnection = createConnection(opts);
   const createConnectionErr = new Error();
   const thePromise = opts.Promise || Promise;
   if (!thePromise) {
@@ -290,12 +293,12 @@ function createConnection(opts) {
     const func = functionsToWrap[i];
 
     if (
-      typeof common.Connection.prototype[func] === 'function' &&
+      typeof Connection.prototype[func] === 'function' &&
       PromiseConnection.prototype[func] === undefined
     ) {
       PromiseConnection.prototype[func] = (function factory(funcName) {
         return function () {
-          return common.Connection.prototype[funcName].apply(
+          return Connection.prototype[funcName].apply(
             this.connection,
             arguments
           );
@@ -411,8 +414,8 @@ class PromisePool extends EventEmitter {
   }
 }
 
-function createPool(opts) {
-  const corePool = common.createPool(opts);
+function createPromisePool(opts) {
+  const corePool = createPool(opts);
   const thePromise = opts.Promise || Promise;
   if (!thePromise) {
     throw new Error(
@@ -545,8 +548,8 @@ class PromisePoolCluster extends EventEmitter {
   'add'
 ]);
 
-function createPoolCluster(opts) {
-  const corePoolCluster = common.createPoolCluster(opts);
+function createPromisePoolCluster(opts) {
+  const corePoolCluster = createPoolCluster(opts);
   const thePromise = (opts && opts.Promise) || Promise;
   if (!thePromise) {
     throw new Error(
@@ -558,9 +561,9 @@ function createPoolCluster(opts) {
   return new PromisePoolCluster(corePoolCluster, thePromise);
 }
 
-exports.createConnection = createConnection;
-exports.createPool = createPool;
-exports.createPoolCluster = createPoolCluster;
+exports.createConnection = createConnectionPromise;
+exports.createPool = createPromisePool;
+exports.createPoolCluster = createPromisePoolCluster;
 exports.escape = SqlString.escape;
 exports.escapeId = SqlString.escapeId;
 exports.format = SqlString.format;