Emit errors only when listeners are present (#66)

* Emit errors only when listeners are present

* On socket end don't emit an additional event

Author: alexpenev-s

lib/protocol/Connection.js

@@ -223,8 +223,10 @@ Connection.prototype._addListeners = function _addListeners(socket) {
     if (cb) {
       self._state.receive = null; // a callback should be called only once
       cb(err);
-    } else {
+    } else if (self.listeners('error').length) {
       self.emit('error', err);
+    } else {
+      debug('onerror', err);
     }
   }
   socket.on('error', onerror);
@@ -239,7 +241,7 @@ Connection.prototype._addListeners = function _addListeners(socket) {
   function onend() {
     var err = new Error('Connection closed by server');
     err.code = 'EHDBCLOSE';
-    socket.emit('error', err);
+    onerror(err);
   }
   socket.on('end', onend);
 };

lib/protocol/ConnectionManager.js

@@ -78,11 +78,6 @@ ConnectionManager.prototype._openConnectionMultiDbCase = function _openConnectio
     }
   }
 
-  function onError(err) {
-    cb(err);
-  }
-  conn.on('error', onError);
-
   function handleError(err) {
     conn.close();
     cb(err);
@@ -99,7 +94,6 @@ ConnectionManager.prototype._openConnectionMultiDbCase = function _openConnectio
       }
 
       if (info.isConnected) {
-        conn.removeListener('error', onError);
         cb(null);
       } else {
         conn._closeSilently();

test/hdb.Client.js

@@ -513,12 +513,12 @@ describe('hdb', function () {
           databaseName: 'DB0'
         });
 
-        client._connection.fetchDbConnectInfo = function () {
-          client._connection.emit('error', new Error('Network error emitted'));
+        client._connection.fetchDbConnectInfo = function (options, cb) {
+          cb(new Error('Network error'));
         };
 
         client.connect(function (err) {
-          err.message.should.equal('Could not connect to any host: [ localhost:30013 - Network error emitted ]');
+          err.message.should.equal('Could not connect to any host: [ localhost:30013 - Network error ]');
           done();
         });
       });