Fixed reconnect logic in MySQL adapter, added test

geddy · Mar 3, 2014 · acb8b43 · acb8b43
1 parent 98e3e17
commit acb8b43
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Showing 2 changed files with 44 additions and 7 deletions.
diff --git a/lib/adapters/sql/mysql.js b/lib/adapters/sql/mysql.js
@@ -4,6 +4,8 @@ var utils = require('utilities')
   , model = require('../../../lib')
   , Query = require('../../../lib/query/query').Query
   , BaseAdapter = require('./base').Adapter
+  , RECONNECT_TRIES_LIMIT = 3
+  , reconnectAttempts = 0
   , Adapter
   , _baseConfig;
 
@@ -39,21 +41,27 @@ utils.mixin(Adapter.prototype, new (function () {
 
   this.COLUMN_NAME_DELIMITER = '`';
 
-  this.handleDisconnect = function () {
+  // Pseudo-private -- utility and for testing only
+  this._getClient = function () {
+    return mysql.createConnection(this.config);
+  };
+
+  this._handleDisconnect = function (callback) {
       var self = this;
       setTimeout(function() {
-        self.client = mysql.createConnection(self.config);
-        self.connect();
+        self.client = self._getClient();
+        self.connect(callback);
       }, Math.pow(3, reconnectAttempts) * 1000);
       reconnectAttempts++;
   };
 
   this.init = function () {
     var self = this;
-    this.client = mysql.createConnection(this.config);
+    this.client = this._getClient();
     this.client.on('error', function(err) {
-      if (err.code === 'PROTOCOL_CONNECTION_LOST' && reconnectAttempts < RECONNECT_TRIES_LIMIT) {
-        self.handleDisconnect();
+      if (err.code === 'PROTOCOL_CONNECTION_LOST' &&
+          reconnectAttempts < RECONNECT_TRIES_LIMIT) {
+        self._handleDisconnect();
       };
    });
   };
@@ -64,7 +72,7 @@ utils.mixin(Adapter.prototype, new (function () {
     this.client.connect(function (err, data) {
       if (err) {
         if (reconnectAttempts < RECONNECT_TRIES_LIMIT) {
-          self.handleDisconnect();
+          self._handleDisconnect(callback);
         } else {
           self.emit('error', err);
           cb(err);

diff --git a/test/integration/adapters/sql/mysql.js b/test/integration/adapters/sql/mysql.js
@@ -60,6 +60,35 @@ tests = {
     assert.ok(adapter instanceof Adapter);
   }
 
+, 'test reconnect logic': function (next) {
+    // Get a reference to the original client func
+    var origGetClient = adapter._getClient;
+    // Punch out the client func with one that returns a client
+    // whose `connect` method always produces an error
+    adapter._getClient = function () {
+      var client = origGetClient.call(adapter);
+      // Always error
+      client.connect = function (cb) {
+        cb({}, null);
+      };
+      return client;
+    };
+    // Disconnect, and try to reconnect -- this will fail
+    adapter.disconnect(function (err, data) {
+      // Until the _getClient function is replaced, this will continue
+      // retrying, once we put it back, reconnect will succeed and
+      // tests will resume
+      adapter.connect(function (err, data) {
+        next();
+      });
+      // Wait three seconds, restore the _getClient func to return
+      // a good client
+      setTimeout(function () {
+        adapter._getClient = origGetClient;
+      }, 3000);
+    });
+  }
+
 , 'test exec': function (next) {
     adapter.exec('CREATE TABLE foo (bar varchar(256) ); DROP TABLE foo;',
         function (err, data) {