feat(trackingZone): Keep track of tasks to see outstanding tasks.

gulpfile.js

@@ -98,11 +98,19 @@ gulp.task('build/long-stack-trace-zone.min.js', function(cb) {
 });
 
 gulp.task('build/proxy-zone.js', function(cb) {
-  return generateBrowserScript('./lib/zone-spec/proxy.ts', 'proxy-zone.js', false, cb);
+  return generateBrowserScript('./lib/zone-spec/proxy-zone.ts', 'proxy-zone.js', false, cb);
 });
 
 gulp.task('build/proxy-zone.min.js', function(cb) {
-  return generateBrowserScript('./lib/zone-spec/proxy.ts', 'proxy-zone.min.js', true, cb);
+  return generateBrowserScript('./lib/zone-spec/proxy-zone.ts', 'proxy-zone.min.js', true, cb);
+});
+
+gulp.task('build/task-tracking.js', function(cb) {
+  return generateBrowserScript('./lib/zone-spec/task-tracking.ts', 'task-tracking.js', false, cb);
+});
+
+gulp.task('build/task-tracking.min.js', function(cb) {
+  return generateBrowserScript('./lib/zone-spec/task-tracking.ts', 'task-tracking.min.js', true, cb);
 });
 
 gulp.task('build/wtf.js', function(cb) {
@@ -136,6 +144,8 @@ gulp.task('build', [
   'build/long-stack-trace-zone.min.js',
   'build/proxy-zone.js',
   'build/proxy-zone.min.js',
+  'build/task-tracking.js',
+  'build/task-tracking.min.js',
   'build/wtf.js',
   'build/wtf.min.js',
   'build/async-test.js',

lib/zone-spec/task-tracking.ts

@@ -0,0 +1,68 @@
+/**
+ * A `TaskTrackingZoneSpec` allows one to track all outstanding Tasks. 
+ * 
+ * This is useful in tests. For example to see which tasks are preventing a test from completing
+ * or an automated way of releasing all of the event listeners at the end of the test.
+ */
+class TaskTrackingZoneSpec implements ZoneSpec {
+  name = 'TaskTrackingZone';
+  microTasks: Task[] = []; 
+  macroTasks: Task[] = []; 
+  eventTasks: Task[] = [];
+  properties: {[key: string]: any} = {'TaskTrackingZone': this}; 
+
+  static get() {
+    return Zone.current.get('TaskTrackingZone');
+  }
+
+  private getTasksFor(type: string): Task [] {
+    switch (type) {
+      case 'microTask': return this.microTasks;
+      case 'macroTask': return this.macroTasks;
+      case 'eventTask': return this.eventTasks;
+    }
+    throw new Error('Unknown task format: ' + type);
+  }
+
+  onScheduleTask(parentZoneDelegate: ZoneDelegate, currentZone: Zone, targetZone: Zone, task: Task): Task {
+    task['creationLocation'] = new Error(`Task '${task.type}' from '${task.source}'.`);
+    const tasks = this.getTasksFor(task.type);
+    tasks.push(task);
+    return parentZoneDelegate.scheduleTask(targetZone, task);
+  }
+
+  onCancelTask(parentZoneDelegate: ZoneDelegate, currentZone: Zone, targetZone: Zone, task: Task): any {
+    const tasks = this.getTasksFor(task.type);
+    for(var i = 0; i < tasks.length; i++) {
+      if (tasks[i] == task) {
+        tasks.splice(i, 1);
+        break;
+      }
+    }
+    return parentZoneDelegate.cancelTask(targetZone, task);
+  }
+
+  onInvokeTask(parentZoneDelegate: ZoneDelegate, currentZone: Zone, targetZone: Zone,
+                  task: Task, applyThis: any, applyArgs: any): any 
+  {
+    if (task.type === 'eventTask')  return parentZoneDelegate.invokeTask(targetZone, task, applyThis, applyArgs);
+    const tasks = this.getTasksFor(task.type);
+    for(var i = 0; i < tasks.length; i++) {
+      if (tasks[i] == task) {
+        tasks.splice(i, 1);
+        break;
+      }
+    }
+    return parentZoneDelegate.invokeTask(targetZone, task, applyThis, applyArgs);
+  }
+
+  clearEvents() {
+    while (this.eventTasks.length) {
+      Zone.current.cancelTask(this.eventTasks[0]);
+    }
+  }
+}
+
+// Export the class so that new instances can be created with proper
+// constructor params.
+Zone['TaskTrackingZoneSpec'] = TaskTrackingZoneSpec;

test/common_tests.ts

@@ -9,3 +9,4 @@ import './zone-spec/async-test.spec';
 import './zone-spec/sync-test.spec';
 import './zone-spec/fake-async-test.spec';
 import './zone-spec/proxy.spec';
+import './zone-spec/task-tracking.spec';

test/zone-spec/task-tracking.spec.ts

@@ -0,0 +1,69 @@
+import '../../lib/zone-spec/task-tracking';
+
+describe('TaskTrackingZone', function() {
+  let _TaskTrackingZoneSpec: typeof TaskTrackingZoneSpec = Zone['TaskTrackingZoneSpec'];
+  let taskTrackingZoneSpec: TaskTrackingZoneSpec = null;
+  let taskTrackingZone: Zone;
+
+  beforeEach(() => {
+    taskTrackingZoneSpec = new _TaskTrackingZoneSpec();
+    taskTrackingZone = Zone.current.fork(taskTrackingZoneSpec);
+  });
+
+  it('should track tasks', (done: Function) => {
+    taskTrackingZone.run(() => {
+      const microTask = taskTrackingZone.scheduleMicroTask('test1', () => {});
+      expect(taskTrackingZoneSpec.microTasks.length).toBe(1);
+      expect(taskTrackingZoneSpec.microTasks[0].source).toBe('test1');
+
+      const macroTask = setTimeout(() => {}) as any as Task;
+      expect(taskTrackingZoneSpec.macroTasks.length).toBe(1);
+      expect(taskTrackingZoneSpec.macroTasks[0].source).toBe('setTimeout');
+      taskTrackingZone.cancelTask(macroTask);
+      expect(taskTrackingZoneSpec.macroTasks.length).toBe(0);
+
+      setTimeout(() => {
+        // assert on execution it is null
+        expect(taskTrackingZoneSpec.macroTasks.length).toBe(0);
+        expect(taskTrackingZoneSpec.microTasks.length).toBe(0);
+
+        const xhr = new XMLHttpRequest();
+        xhr.open('get', '/', true);
+        xhr.onreadystatechange = () => {
+          if (xhr.readyState == 4) {
+            // clear current event tasks using setTimeout
+            setTimeout(() => {
+              expect(taskTrackingZoneSpec.macroTasks.length).toBe(0);
+              expect(taskTrackingZoneSpec.microTasks.length).toBe(0);
+              expect(taskTrackingZoneSpec.eventTasks.length).toBe(2);
+              taskTrackingZoneSpec.clearEvents();
+              expect(taskTrackingZoneSpec.eventTasks.length).toBe(0);
+              done();
+            });
+          }
+        };
+        xhr.send();
+        expect(taskTrackingZoneSpec.macroTasks.length).toBe(1);
+        expect(taskTrackingZoneSpec.macroTasks[0].source).toBe('XMLHttpRequest.send');
+
+        expect(taskTrackingZoneSpec.eventTasks.length).toBe(2);
+        // one for me
+        expect(taskTrackingZoneSpec.eventTasks[0].source).toBe('XMLHttpRequest.addEventListener:readystatechange');
+        // one for internall tracking of XHRs.
+        expect(taskTrackingZoneSpec.eventTasks[1].source).toBe('XMLHttpRequest.addEventListener:readystatechange');
+      });
+
+    });    
+  });
+
+  it('should capture task creation stacktrace', (done) => {
+    taskTrackingZone.run(() => {
+      const task = setTimeout(() => {
+        done();
+      }) as any as Task;
+      expect(task['creationLocation']).toBeTruthy();
+    });
+  });
+});
+
+export var __something__;