feat: report error on Sentinel connection refused (#445) (#446)

* Report error on Sentinel connection refused

* Removed duplicate line, oops

* Errors emitted instead of called back

* Spacing

* Fixed error reporting to event reporting

lib/connectors/sentinel_connector.js

@@ -28,7 +28,7 @@ SentinelConnector.prototype.check = function (info) {
   return true;
 };
 
-SentinelConnector.prototype.connect = function (callback) {
+SentinelConnector.prototype.connect = function (callback, eventEmitter) {
   this.connecting = true;
   this.retryAttempts = 0;
 
@@ -48,20 +48,24 @@ SentinelConnector.prototype.connect = function (callback) {
     if (_this.currentPoint === _this.sentinels.length) {
       _this.currentPoint = -1;
 
+      var error;
       var retryDelay;
       if (typeof _this.options.sentinelRetryStrategy === 'function') {
         retryDelay = _this.options.sentinelRetryStrategy(++_this.retryAttempts);
       }
+
       if (typeof retryDelay !== 'number') {
         debug('All sentinels are unreachable and retry is disabled, emitting error...');
-        var error = 'All sentinels are unreachable.';
+        error = 'All sentinels are unreachable.';
         if (lastError) {
           error += ' Last error: ' + lastError.message;
         }
         return callback(new Error(error));
       }
       debug('All sentinels are unreachable. Retrying from scratch after %d', retryDelay);
+      error = 'All sentinels are unreachable, retrying...';
       setTimeout(connectToNext, retryDelay);
+      eventEmitter('error', new Error(error));
       return;
     }
 
@@ -76,11 +80,13 @@ SentinelConnector.prototype.connect = function (callback) {
         callback(null, _this.stream);
       } else if (err) {
         debug('failed to connect to sentinel %s:%s because %s', endpoint.host, endpoint.port, err);
+        eventEmitter('sentinelError', new Error('failed to connect to sentinel '+endpoint.host+':'+endpoint.port+' because '+err));
         lastError = err;
         connectToNext();
       } else {
         debug('connected to sentinel %s:%s successfully, but got a invalid reply: %s',
           endpoint.host, endpoint.port, resolved);
+        eventEmitter('sentinelError', new Error('connected to sentinel '+endpoint.host+':'+endpoint.port+' successfully, but got a invalid reply: '+resolved));
         connectToNext();
       }
     });

lib/redis.js

@@ -311,6 +311,8 @@ Redis.prototype.connect = function (callback) {
       };
       _this.once(CONNECT_EVENT, connectionConnectHandler);
       _this.once('close', connectionCloseHandler);
+    }, function(type, err) {
+      _this.silentEmit(type, err);
     });
   }.bind(this)).nodeify(callback);
 };