Rewrite callbacks to arrow functions

.eslintrc

@@ -2,11 +2,14 @@
   "root": true,
   "extends": "nodules",
   "rules": {
+    "arrow-parens": ["error", "as-needed"],
+    "arrow-spacing": "error",
     "no-console": 0,
     "no-mixed-requires": 0,
     "no-multiple-empty-lines": [2, {"max": 1}],
     "no-var": "error",
-    "global-require": 0
+    "global-require": 0,
+    "prefer-arrow-callback": "error"
   },
   "env": {
     "es6": true,

examples/custom_master_and_ipc/master.js

@@ -12,8 +12,8 @@ if (proc.isMaster) {
          * @param {WorkerWrapper} sender
          * @param {*} value
          */
-        function(sender, value) {
-            proc.forEach(function(worker) {
+        (sender, value) => {
+            proc.forEach(worker => {
                 // repeat command to all workers except `sender`
                 if (worker.id !== sender.id) {
                     // pass sender.wid to another workers know command source

examples/custom_master_and_ipc/worker.js

@@ -10,13 +10,13 @@ counters[worker.id] = 0;
 
 worker.registerRemoteCommand(
     'updateCounter',
-    function(target, workerId, value) {
+    (target, workerId, value) => {
         // update recieved counter
         counters[workerId] = value;
     });
 
 http
-    .createServer(function(req, res) {
+    .createServer((req, res) => {
         res.end('Worker #' + worker.id + ' at your service, sir!\n\nCounters: ' + JSON.stringify(counters));
 
         // update counter in another workers

examples/simple_extension/worker.js

@@ -6,7 +6,7 @@ if (cluster.worker.id === 1) {
 }
 
 http
-    .createServer(function(req, res) {
+    .createServer((req, res) => {
         res.end('Worker #' + cluster.worker.id + ' at your service, sir!');
     })
     .listen(process.env.port);

examples/simple_server/worker.js

@@ -6,7 +6,7 @@ if (worker.wid === 1 || worker.wid === 0) {
 }
 
 http
-    .createServer(function(req, res) {
+    .createServer((req, res) => {
         res.end('Worker #' + worker.wid + ' at your service, sir!');
     })
     .listen(process.env.port);

lib/cluster_process.js

@@ -147,11 +147,9 @@ class ClusterProcess extends EventEmitterEx {
         config = Configuration.extend(config, this.config.getBaseDir());
 
         if (extension.configure.length > 2) {
-            setImmediate(function() {
-                extension.configure(config, self, callback);
-            });
+            setImmediate(() => extension.configure(config, self, callback));
         } else {
-            setImmediate(function() {
+            setImmediate(() => {
                 extension.configure(config, self);
                 callback();
             });
@@ -188,8 +186,8 @@ class ClusterProcess extends EventEmitterEx {
             return;
         }
 
-        extensions.forEach(function(name) {
-            this.loadExtension(name, function(error) {
+        extensions.forEach(name => {
+            this.loadExtension(name, error => {
                 if (error) {
                     return self.emit('error', error);
                 }
@@ -203,12 +201,10 @@ class ClusterProcess extends EventEmitterEx {
                     self.emit('initialized');
                 }
             });
-        }, this);
+        });
 
-        loadTimer = setTimeout(function() {
-            const timeouted = extensions.filter(function(name) {
-                    return !loadedExtensions.has(name);
-                }),
+        loadTimer = setTimeout(() => {
+            const timeouted = extensions.filter(name => !loadedExtensions.has(name)),
                 error = LusterClusterProcessError.createError(
                     LusterClusterProcessError.CODES.EXTENSIONS_LOAD_TIMEOUT,
                     {timeouted: timeouted, timeout: loadTimeout});
@@ -323,11 +319,11 @@ class ClusterProcess extends EventEmitterEx {
          * @param {*} [data]
          * @param {String} callbackId
          */
-        this.registerRemoteCommand(command, function(proc, data, callbackId) {
+        this.registerRemoteCommand(command, (proc, data, callbackId) => {
             /**
              * @param {*} [callbackData]
              */
-            return handler(function(callbackData) {
+            return handler(callbackData => {
                 proc.remoteCall(RPC.fns.callback, callbackId, callbackData);
             }, data);
         });

lib/master.js

@@ -66,9 +66,7 @@ class Master extends ClusterProcess {
      */
     _onSignalQuit() {
         this
-            .once('shutdown', function() {
-                process.exit(0);
-            })
+            .once('shutdown', () => process.exit(0))
             .shutdown();
     }
 
@@ -88,14 +86,14 @@ class Master extends ClusterProcess {
         }
 
         const self = this,
-            inUse = this.getWorkersArray().some(function(w) {
-                return worker.wid !== w.wid &&
-                    w.isRunning() &&
-                    port.isEqualTo(w.options.port);
-            });
+            inUse = this.getWorkersArray().some(w =>
+                worker.wid !== w.wid &&
+                w.isRunning() &&
+                port.isEqualTo(w.options.port)
+            );
 
         if (!inUse) {
-            port.unlink(function(err) {
+            port.unlink(err => {
                 if (err) {
                     self.emit('error', err);
                 }
@@ -109,9 +107,10 @@ class Master extends ClusterProcess {
      */
     _checkWorkersAlive() {
         const workers = this.getWorkersArray(),
-            alive = workers.reduce(function(count, w) {
-                return w.dead ? count - 1 : count;
-            }, workers.length);
+            alive = workers.reduce(
+                (count, w) => w.dead ? count - 1 : count,
+                workers.length
+            );
 
         if (alive === 0) {
             this.emit('shutdown');
@@ -126,9 +125,10 @@ class Master extends ClusterProcess {
      */
     _proxyWorkerEvents(worker) {
         WorkerWrapper.EVENTS
-            .forEach(function(eventName) {
-                worker.on(eventName, this.emit.bind(this, 'worker ' + eventName, worker));
-            }, this);
+            .forEach(eventName => {
+                const proxyEventName = 'worker ' + eventName;
+                worker.on(eventName, this.emit.bind(this, proxyEventName, worker));
+            });
     }
 
     /**
@@ -182,9 +182,10 @@ class Master extends ClusterProcess {
      *      }, master);
      */
     forEach(fn) {
-        this.getWorkersArray().forEach(function(worker) {
-            fn.call(this, worker);
-        }, this);
+        this.getWorkersArray()
+            .forEach(
+                worker => fn.call(this, worker)
+            );
 
         return this;
     }
@@ -248,24 +249,23 @@ class Master extends ClusterProcess {
      * @returns {Master} self
      */
     waitForWorkers(wids, event, callback) {
-        const self = this;
         const pendingWids = new Set(wids);
 
-        function onWorkerState(worker) {
+        const onWorkerState = worker => {
             const wid = worker.wid;
             if (pendingWids.has(wid)) {
                 pendingWids.delete(wid);
             }
             if (pendingWids.size === 0) {
-                self.removeListener(event, onWorkerState);
-                callback.call(self);
+                this.removeListener(event, onWorkerState);
+                callback.call(this);
             }
-        }
+        };
 
         if (wids.length > 0) {
             this.on(event, onWorkerState);
         } else {
-            setImmediate(callback.bind(self));
+            setImmediate(callback.bind(this));
         }
 
         return this;
@@ -306,9 +306,8 @@ class Master extends ClusterProcess {
 
         this.waitForAllWorkers(
             'worker ready',
-            function() {
-                this.emit('restarted');
-            });
+            () => this.emit('restarted')
+        );
 
         return this;
     }
@@ -322,9 +321,7 @@ class Master extends ClusterProcess {
      * @fires Master#restarted when workers spawned and ready.
      */
     softRestart() {
-        this.forEach(function(worker) {
-            worker.softRestart();
-        });
+        this.forEach(worker => worker.softRestart());
         this._restartQueue.once('drain', this.emit.bind(this, 'restarted'));
         return this;
     }
@@ -359,11 +356,11 @@ class Master extends ClusterProcess {
      * @public
      */
     remoteCallToAll(name, ...args) {
-        this.forEach(function(worker) {
+        this.forEach(worker => {
             if (worker.ready) {
                 worker.remoteCall(name, ...args);
             } else {
-                worker.on('ready', function() {
+                worker.on('ready', () => {
                     worker.remoteCall(name, ...args);
                 });
             }
@@ -378,7 +375,7 @@ class Master extends ClusterProcess {
      * @public
      */
     broadcastEventToAll(event, ...args) {
-        this.forEach(function(worker) {
+        this.forEach(worker => {
             if (worker.ready) {
                 worker.broadcastEvent(event, ...args);
             }
@@ -409,7 +406,7 @@ class Master extends ClusterProcess {
     shutdown() {
         const stoppedWorkers = [];
 
-        this.forEach(function(worker) {
+        this.forEach(worker => {
             if (worker.isRunning()) {
                 worker.stop();
                 stoppedWorkers.push(worker.wid);
@@ -419,9 +416,8 @@ class Master extends ClusterProcess {
         this.waitForWorkers(
             stoppedWorkers,
             'worker exit',
-            function() {
-                this.emit('shutdown');
-            });
+            () => this.emit('shutdown')
+        );
 
         return this;
     }
@@ -436,7 +432,7 @@ class Master extends ClusterProcess {
      * @public
      */
     remoteCallToAllWithCallback(opts) {
-        this.forEach(function(worker) {
+        this.forEach(worker => {
             if (worker.isRunning()) {
                 worker.remoteCallWithCallback(opts);
             }
@@ -473,9 +469,8 @@ Master.prototype.run = Master.whenInitialized(function() {
 
     this.waitForAllWorkers(
         'worker ready',
-        function() {
-            this.emit('running');
-        });
+        () => this.emit('running')
+    );
 
     return this;
 });

lib/port.js

@@ -86,7 +86,7 @@ class Port {
             return;
         }
 
-        fs.unlink(value, function(err) {
+        fs.unlink(value, err => {
             if (err && err.code !== 'ENOENT') {
                 cb(LusterPortError
                     .createError(LusterPortError.CODES.CAN_NOT_UNLINK_UNIX_SOCKET, err)

lib/restart_queue.js

@@ -36,13 +36,13 @@ class RestartQueue extends EventEmitterEx {
             return;
         }
 
-        const removeWorker = function() {
+        const removeWorker = () => {
             worker.removeListener('ready', removeWorker);
             worker.removeListener('state', checkDead);
             this._remove(worker);
-        }.bind(this);
+        };
 
-        const checkDead = function(state) {
+        const checkDead = state => {
             if (state === WorkerWrapper.STATES.STOPPED && worker.dead) {
                 removeWorker();
             }

lib/rpc-callback.js

@@ -13,25 +13,24 @@ const RPCCallback = {
      * @returns {String} callbackId
      */
     setCallback: function(proc, command, callback, timeout) {
-        const self = this,
-            storage = self._storage;
+        const storage = this._storage;
 
         if ( ! timeout) {
             timeout = 10000;
         }
 
-        const callbackId = proc.wid + '_' + self._counter++;
+        const callbackId = proc.wid + '_' + this._counter++;
 
         storage[callbackId] = {
             callback: callback,
             timeout:
-                setTimeout(function() {
+                setTimeout(() => {
                     storage[callbackId].callback(
                         proc,
                         LusterRPCCallbackError.createError(
                             LusterRPCCallbackError.CODES.REMOTE_CALL_WITH_CALLBACK_TIMEOUT,
                             { command: command }));
-                    self.removeCallback(callbackId);
+                    this.removeCallback(callbackId);
                 }, timeout)
         };
 
@@ -50,9 +49,7 @@ const RPCCallback = {
             return;
         }
 
-        setImmediate(function() {
-            stored.callback(proc, null, data);
-        });
+        setImmediate(() => stored.callback(proc, null, data));
         this.removeCallback(callbackId);
     },