Websocket bugfix (#750)

* Close connection on error'

* Log errors when sending messages to websocket

* Send poweredOn when connecting and forward state changes

* Make sure the event handler are setup before sending poweredOn

lib/websocket/bindings.js

@@ -19,6 +19,7 @@ var NobleBindings = function() {
 
   this._ws.on('open', this._onOpen.bind(this));
   this._ws.on('close', this._onClose.bind(this));
+  this._ws.on('error', this._onClose.bind(this));
 
   var _this = this;
   this._ws.on('message', function(event) {
@@ -40,7 +41,6 @@ NobleBindings.prototype._onOpen = function() {
 
 NobleBindings.prototype._onClose = function() {
   console.log('on -> close');
-
   this.emit('stateChange', 'poweredOff');
 };
 
@@ -119,10 +119,16 @@ NobleBindings.prototype._onMessage = function(event) {
   }
 };
 
-NobleBindings.prototype._sendCommand = function(command) {
+NobleBindings.prototype._sendCommand = function(command, errorCallback) {
   var message = JSON.stringify(command);
-
-  this._ws.send(message);
+    this._ws.send(message, function(error) {
+      if (error != null) {
+        console.warn("could not send command", command, error);
+        if (typeof errorCallback === "function") {
+          errorCallback(error);
+        }
+      }
+    });
 };
 
 NobleBindings.prototype.startScanning = function(serviceUuids, allowDuplicates) {

ws-slave.js

@@ -25,18 +25,29 @@ if (serverMode) {
 
     ws = ws_;
 
-    sendEvent({
-      type: 'stateChange',
-      state: noble.state
-    });
-
     ws.on('message', onMessage);
 
     ws.on('close', function() {
       console.log('ws -> close');
-
       noble.stopScanning();
     });
+
+    noble.on('stateChange', function(state) {
+      sendEvent({
+        type: 'stateChange',
+        state: state
+      });
+    });
+
+    // Send poweredOn if already in this state.
+    if (noble.state == "poweredOn") {
+      sendEvent({
+        type: 'stateChange',
+        state: "poweredOn"
+      });
+    }
+
+
   });
 } else {
   ws = new WebSocket('ws://' + host + ':' + port);