Add Pool#connection event, which emits when an open connection has succesfully been added to the pool, but before any Pool#getConnection callbacks are called. This allows for a pool of connections to e.g. set MySQL session variables on each of its connections before they are used

Author: marcuswestin

lib/Pool.js

@@ -1,9 +1,13 @@
 
 var Mysql        = require('../');
 var Connection   = require('./Connection');
+var EventEmitter = require('events').EventEmitter;
+var Util         = require('util');
 
 module.exports = Pool;
+Util.inherits(Pool, EventEmitter);
 function Pool(options) {
+  EventEmitter.call(this);
   this.config = options.config;
   this.config.connectionConfig.pool = this;
 
@@ -34,6 +38,7 @@ Pool.prototype.getConnection = function(cb) {
       else if (err) {
         cb(err);
       } else {
+        self.emit('connection', null, connection);
         cb(null, connection);
       }
     });

test/integration/pool/test-set-session-vars.js

@@ -0,0 +1,16 @@
+var common     = require('../../common');
+var assert     = require('assert');
+var Connection = require(common.lib + '/Connection');
+var pool       = common.createPool();
+
+var wasSet = false;
+pool.on('connection', function(err, connection) {
+  connection.query('SET SESSION sql_mode="STRICT_ALL_TABLES"');
+  wasSet = true;
+})
+
+pool.getConnection(function(err, connection) {
+  if (err) throw err;
+  assert.equal(wasSet, true);
+  pool.end();
+});