feat: buffer result messages when polling

Some browsers (Safari) starts loosing messages when sending too often (using xhr/html polling). Batching solves the issue.

lib/browser.js

@@ -151,6 +151,10 @@ var Browser = function(id, fullName, /* capturedBrowsers */ collection, emitter,
   };
 
   this.onResult = function(result) {
+    if (result.length) {
+      return result.forEach(this.onResult, this);
+    }
+
     // ignore - probably results from last run (after server disconnecting)
     if (this.isReady()) {
       return;

static/karma.src.js

@@ -50,6 +50,9 @@ var Karma = function(socket, context, navigator, location) {
   var store = {};
   var self = this;
 
+  var resultsBufferLimit = 1;
+  var resultsBuffer = [];
+
   this.VERSION = VERSION;
   this.config = {};
 
@@ -190,10 +193,24 @@ var Karma = function(socket, context, navigator, location) {
   };
 
   this.result = function(result) {
-    socket.emit('result', result);
+    if (resultsBufferLimit === 1) {
+      return socket.emit('result', result);
+    }
+
+    resultsBuffer.push(result);
+
+    if (resultsBuffer.length === resultsBufferLimit) {
+      socket.emit('result', resultsBuffer);
+      resultsBuffer = [];
+    }
   };
 
   this.complete = function(result) {
+    if (resultsBuffer.length) {
+      socket.emit('result', resultsBuffer);
+      resultsBuffer = [];
+    }
+
     // give the browser some time to breath, there could be a page reload, but because a bunch of
     // tests could run in the same event loop, we wouldn't notice.
     setTimeout(function() {
@@ -252,6 +269,15 @@ var Karma = function(socket, context, navigator, location) {
 
   // report browser name, id
   socket.on('connect', function() {
+    var transport = socket.socket.transport.name;
+
+    // TODO(vojta): make resultsBufferLimit configurable
+    if (transport === 'websocket' || transport === 'flashsocket') {
+      resultsBufferLimit = 1;
+    } else {
+      resultsBufferLimit = 50;
+    }
+
     socket.emit('register', {
       name: navigator.userAgent,
       id: parseInt((location.search.match(/\?id=(.*)/) || [])[1], 10) || null

test/client/karma.spec.js

@@ -6,10 +6,16 @@
 describe('karma', function() {
   var socket, k, spyStart, windowNavigator, windowLocation;
 
+  var setTransportTo = function(transportName) {
+    socket._setTransportNameTo(transportName);
+    socket.emit('connect');
+  };
+
+
   beforeEach(function() {
     socket = new MockSocket();
     windowNavigator = {};
-    windowLocation = {};
+    windowLocation = {search: ''};
     k = new Karma(socket, {}, windowNavigator, windowLocation);
     spyStart = spyOn(k, 'start');
   });
@@ -84,6 +90,45 @@ describe('karma', function() {
   });
 
 
+  describe('result', function() {
+    var spyResult;
+
+    beforeEach(function() {
+      spyResult = jasmine.createSpy('onResult');
+      socket.on('result', spyResult);
+    });
+
+    it('should buffer results when polling', function() {
+      setTransportTo('xhr-polling');
+
+      // emit 49 results
+      for (var i = 1; i < 50; i++) {
+        k.result({id: i});
+      }
+
+      expect(spyResult).not.toHaveBeenCalled();
+
+      k.result('result', {id: 50});
+      expect(spyResult).toHaveBeenCalled();
+      expect(spyResult.argsForCall[0][0].length).toBe(50);
+    });
+
+
+    it('should buffer results when polling', function() {
+      setTransportTo('xhr-polling');
+
+      // emit 40 results
+      for (var i = 1; i <= 40; i++) {
+        k.result({id: i});
+      }
+
+      k.complete();
+      expect(spyResult).toHaveBeenCalled();
+      expect(spyResult.argsForCall[0][0].length).toBe(40);
+    });
+  });
+
+
   describe('setupContext', function() {
     it('should capture alert', function() {
       spyOn(k, 'log');

test/client/mocks.js

@@ -27,7 +27,18 @@ var Emitter = function() {
   };
 };
 
-var MockSocket = Emitter;
+
+var MockSocket = function() {
+  Emitter.call(this);
+
+  this.socket = {transport: {name: 'websocket'}};
+
+  // MOCK API
+  this._setTransportNameTo = function(transportName) {
+    this.socket.transport.name = transportName;
+  };
+};
+
 
 var io = {
   connect: function() {

test/unit/browser.spec.coffee

@@ -329,6 +329,16 @@ describe 'browser', ->
         expect(browser.lastResult.netTime).to.equal 9
 
 
+      it 'should accept array of results', ->
+        browser.state = b.Browser.STATE_EXECUTING
+        browser.onResult [createSuccessResult(), createSuccessResult(),
+                          createFailedResult(), createSkippedResult()]
+
+        expect(browser.lastResult.success).to.equal 2
+        expect(browser.lastResult.failed).to.equal 1
+        expect(browser.lastResult.skipped).to.equal 1
+
+
     #==========================================================================
     # browser.Browser.serialize
     #==========================================================================