feat(refactor): replaced ObservablePipe and PromisePipe with AsyncPipe

modules/angular2/pipes.ts

@@ -4,10 +4,9 @@
  * This module provides advanced support for extending change detection.
  */
 
-export {PromisePipe} from './src/change_detection/pipes/promise_pipe';
 export {UpperCasePipe} from './src/change_detection/pipes/uppercase_pipe';
 export {LowerCasePipe} from './src/change_detection/pipes/lowercase_pipe';
-export {ObservablePipe} from './src/change_detection/pipes/observable_pipe';
+export {AsyncPipe} from './src/change_detection/pipes/async_pipe';
 export {JsonPipe} from './src/change_detection/pipes/json_pipe';
 export {DatePipe} from './src/change_detection/pipes/date_pipe';
 export {DecimalPipe, PercentPipe, CurrencyPipe} from './src/change_detection/pipes/number_pipe';

modules/angular2/src/change_detection/change_detection.ts

@@ -7,8 +7,7 @@ import {IterableDiffers, IterableDifferFactory} from './differs/iterable_differs
 import {DefaultIterableDifferFactory} from './differs/default_iterable_differ';
 import {KeyValueDiffers, KeyValueDifferFactory} from './differs/keyvalue_differs';
 import {DefaultKeyValueDifferFactory} from './differs/default_keyvalue_differ';
-import {ObservablePipeFactory} from './pipes/observable_pipe';
-import {PromisePipeFactory} from './pipes/promise_pipe';
+import {AsyncPipeFactory} from './pipes/async_pipe';
 import {UpperCasePipe} from './pipes/uppercase_pipe';
 import {LowerCasePipe} from './pipes/lowercase_pipe';
 import {JsonPipe} from './pipes/json_pipe';
@@ -75,11 +74,8 @@ export const iterableDiff: IterableDifferFactory[] =
 /**
  * Async binding to such types as Observable.
  */
-export const async: List<PipeFactory> = CONST_EXPR([
-  CONST_EXPR(new ObservablePipeFactory()),
-  CONST_EXPR(new PromisePipeFactory()),
-  CONST_EXPR(new NullPipeFactory())
-]);
+export const async: List<PipeFactory> =
+    CONST_EXPR([CONST_EXPR(new AsyncPipeFactory()), CONST_EXPR(new NullPipeFactory())]);
 
 /**
  * Uppercase text transform.

modules/angular2/src/change_detection/pipes/async_pipe.ts

@@ -0,0 +1,134 @@
+import {isBlank, isPresent, isPromise, CONST, BaseException} from 'angular2/src/facade/lang';
+import {Observable, Promise, ObservableWrapper} from 'angular2/src/facade/async';
+import {Pipe, WrappedValue, PipeFactory} from './pipe';
+import {ChangeDetectorRef} from '../change_detector_ref';
+
+
+class ObservableStrategy {
+  createSubscription(async: any, updateLatestValue: any): any {
+    return ObservableWrapper.subscribe(async, updateLatestValue, e => { throw e; });
+  }
+
+  dispose(subscription: any): void { ObservableWrapper.dispose(subscription); }
+
+  onDestroy(subscription: any): void { ObservableWrapper.dispose(subscription); }
+}
+
+class PromiseStrategy {
+  createSubscription(async: any, updateLatestValue: any): any {
+    return async.then(updateLatestValue);
+  }
+
+  dispose(subscription: any): void {}
+
+  onDestroy(subscription: any): void {}
+}
+
+var _promiseStrategy = new PromiseStrategy();
+var _observableStrategy = new ObservableStrategy();
+
+
+/**
+ * Implements async bindings to Observable and Promise.
+ *
+ * # Example
+ *
+ * In this example we bind the description observable to the DOM. The async pipe will convert an
+ *observable to the
+ * latest value it emitted. It will also request a change detection check when a new value is
+ *emitted.
+ *
+ *  ```
+ * @Component({
+ *   selector: "task-cmp",
+ *   changeDetection: ON_PUSH
+ * })
+ * @View({
+ *   template: "Task Description {{ description | async }}"
+ * })
+ * class Task {
+ *  description:Observable<string>;
+ * }
+ *
+ * ```
+ */
+export class AsyncPipe implements Pipe {
+  _latestValue: Object = null;
+  _latestReturnedValue: Object = null;
+
+  _subscription: Object = null;
+  _obj: Observable | Promise<any> = null;
+  private _strategy: any = null;
+
+  constructor(public _ref: ChangeDetectorRef) {}
+
+  supports(obj: any): boolean { return true; }
+
+  onDestroy(): void {
+    if (isPresent(this._subscription)) {
+      this._dispose();
+    }
+  }
+
+  transform(obj: Observable | Promise<any>, args?: any[]): any {
+    if (isBlank(this._obj)) {
+      if (isPresent(obj)) {
+        this._subscribe(obj);
+      }
+      return null;
+    }
+
+    if (obj !== this._obj) {
+      this._dispose();
+      return this.transform(obj);
+    }
+
+    if (this._latestValue === this._latestReturnedValue) {
+      return this._latestReturnedValue;
+    } else {
+      this._latestReturnedValue = this._latestValue;
+      return WrappedValue.wrap(this._latestValue);
+    }
+  }
+
+  _subscribe(obj: Observable | Promise<any>): void {
+    this._obj = obj;
+    this._strategy = this._selectStrategy(obj);
+    this._subscription =
+        this._strategy.createSubscription(obj, value => this._updateLatestValue(obj, value));
+  }
+
+  _selectStrategy(obj: Observable | Promise<any>) {
+    if (isPromise(obj)) {
+      return _promiseStrategy;
+    } else if (ObservableWrapper.isObservable(obj)) {
+      return _observableStrategy;
+    } else {
+      throw new BaseException(`Async pipe does not support object '${obj}'`);
+    }
+  }
+
+  _dispose(): void {
+    this._strategy.dispose(this._subscription);
+    this._latestValue = null;
+    this._latestReturnedValue = null;
+    this._subscription = null;
+    this._obj = null;
+  }
+
+  _updateLatestValue(async: any, value: Object) {
+    if (async === this._obj) {
+      this._latestValue = value;
+      this._ref.requestCheck();
+    }
+  }
+}
+
+/**
+ * Provides a factory for [AsyncPipe].
+ */
+@CONST()
+export class AsyncPipeFactory implements PipeFactory {
+  supports(obj: any): boolean { return true; }
+  create(cdRef: ChangeDetectorRef): Pipe { return new AsyncPipe(cdRef); }
+}

modules/angular2/src/change_detection/pipes/observable_pipe.ts

@@ -1,94 +0,0 @@
-import {Observable, ObservableWrapper} from 'angular2/src/facade/async';
-import {isBlank, isPresent, CONST} from 'angular2/src/facade/lang';
-import {Pipe, WrappedValue, PipeFactory} from './pipe';
-import {ChangeDetectorRef} from '../change_detector_ref';
-
-/**
- * Implements async bindings to Observable.
- *
- * # Example
- *
- * In this example we bind the description observable to the DOM. The async pipe will convert an
- *observable to the
- * latest value it emitted. It will also request a change detection check when a new value is
- *emitted.
- *
- *  ```
- * @Component({
- *   selector: "task-cmp",
- *   changeDetection: ON_PUSH
- * })
- * @View({
- *   template: "Task Description {{ description | async }}"
- * })
- * class Task {
- *  description:Observable<string>;
- * }
- *
- * ```
- */
-export class ObservablePipe implements Pipe {
-  _latestValue: Object = null;
-  _latestReturnedValue: Object = null;
-
-  _subscription: Object = null;
-  _observable: Observable = null;
-
-  constructor(public _ref: ChangeDetectorRef) {}
-
-  supports(obs: any): boolean { return ObservableWrapper.isObservable(obs); }
-
-  onDestroy(): void {
-    if (isPresent(this._subscription)) {
-      this._dispose();
-    }
-  }
-
-  transform(obs: Observable, args: List<any> = null): any {
-    if (isBlank(this._subscription)) {
-      this._subscribe(obs);
-      return null;
-    }
-
-    if (obs !== this._observable) {
-      this._dispose();
-      return this.transform(obs);
-    }
-
-    if (this._latestValue === this._latestReturnedValue) {
-      return this._latestReturnedValue;
-    } else {
-      this._latestReturnedValue = this._latestValue;
-      return WrappedValue.wrap(this._latestValue);
-    }
-  }
-
-  _subscribe(obs: Observable): void {
-    this._observable = obs;
-    this._subscription = ObservableWrapper.subscribe(obs, value => this._updateLatestValue(value),
-                                                     e => { throw e; });
-  }
-
-  _dispose(): void {
-    ObservableWrapper.dispose(this._subscription);
-    this._latestValue = null;
-    this._latestReturnedValue = null;
-    this._subscription = null;
-    this._observable = null;
-  }
-
-  _updateLatestValue(value: Object) {
-    this._latestValue = value;
-    this._ref.requestCheck();
-  }
-}
-
-/**
- * Provides a factory for [ObervablePipe].
- */
-@CONST()
-export class ObservablePipeFactory implements PipeFactory {
-  supports(obs: any): boolean { return ObservableWrapper.isObservable(obs); }
-
-  create(cdRef: ChangeDetectorRef): Pipe { return new ObservablePipe(cdRef); }
-}

modules/angular2/src/change_detection/pipes/promise_pipe.ts

@@ -1,84 +0,0 @@
-import {Promise, PromiseWrapper} from 'angular2/src/facade/async';
-import {isBlank, isPresent, isPromise, CONST} from 'angular2/src/facade/lang';
-import {Pipe, PipeFactory, WrappedValue} from './pipe';
-import {ChangeDetectorRef} from '../change_detector_ref';
-
-/**
- * Implements async bindings to Promise.
- *
- * # Example
- *
- * In this example we bind the description promise to the DOM.
- * The async pipe will convert a promise to the value with which it is resolved. It will also
- * request a change detection check when the promise is resolved.
- *
- *  ```
- * @Component({
- *   selector: "task-cmp",
- *   changeDetection: ON_PUSH
- * })
- * @View({
- *   template: "Task Description {{ description | async }}"
- * })
- * class Task {
- *   description:Promise<string>;
- * }
- *
- * ```
- */
-export class PromisePipe implements Pipe {
-  _latestValue: Object = null;
-  _latestReturnedValue: Object = null;
-  _sourcePromise: Promise<any>;
-
-  constructor(public _ref: ChangeDetectorRef) {}
-
-  supports(promise: any): boolean { return isPromise(promise); }
-
-  onDestroy(): void {
-    if (isPresent(this._sourcePromise)) {
-      this._latestValue = null;
-      this._latestReturnedValue = null;
-      this._sourcePromise = null;
-    }
-  }
-
-  transform(promise: Promise<any>, args: List<any> = null): any {
-    if (isBlank(this._sourcePromise)) {
-      this._sourcePromise = promise;
-      promise.then((val) => {
-        if (this._sourcePromise === promise) {
-          this._updateLatestValue(val);
-        }
-      });
-      return null;
-    }
-
-    if (promise !== this._sourcePromise) {
-      this._sourcePromise = null;
-      return this.transform(promise);
-    }
-
-    if (this._latestValue === this._latestReturnedValue) {
-      return this._latestReturnedValue;
-    } else {
-      this._latestReturnedValue = this._latestValue;
-      return WrappedValue.wrap(this._latestValue);
-    }
-  }
-
-  _updateLatestValue(value: Object) {
-    this._latestValue = value;
-    this._ref.requestCheck();
-  }
-}
-
-/**
- * Provides a factory for [PromisePipe].
- */
-@CONST()
-export class PromisePipeFactory implements PipeFactory {
-  supports(promise: any): boolean { return isPromise(promise); }
-
-  create(cdRef: ChangeDetectorRef): Pipe { return new PromisePipe(cdRef); }
-}

modules/angular2/src/test_lib/spies.ts

@@ -1,5 +1,6 @@
 import {
   ChangeDetector,
+  ChangeDetectorRef,
   ProtoChangeDetector,
   DynamicChangeDetector
 } from 'angular2/src/change_detection/change_detection';
@@ -26,3 +27,7 @@ export class SpyPipeFactory extends SpyObject {}
 export class SpyDependencyProvider extends SpyObject {}
 
 export class SpyIterableDifferFactory extends SpyObject {}
+
+export class SpyChangeDetectorRef extends SpyObject {
+  constructor() { super(ChangeDetectorRef); }
+}

modules/angular2/test/change_detection/pipes/async_pipe_spec.ts

@@ -0,0 +1,220 @@
+import {
+  ddescribe,
+  describe,
+  it,
+  iit,
+  xit,
+  expect,
+  beforeEach,
+  afterEach,
+  AsyncTestCompleter,
+  SpyChangeDetectorRef,
+  inject,
+  SpyObject
+} from 'angular2/test_lib';
+
+import {IMPLEMENTS, isBlank} from 'angular2/src/facade/lang';
+import {WrappedValue} from 'angular2/src/change_detection/pipes/pipe';
+import {AsyncPipe} from 'angular2/src/change_detection/pipes/async_pipe';
+import {
+  EventEmitter,
+  ObservableWrapper,
+  PromiseWrapper,
+  TimerWrapper
+} from 'angular2/src/facade/async';
+import {DOM} from 'angular2/src/dom/dom_adapter';
+
+export function main() {
+  describe("AsyncPipe", () => {
+
+    describe('Observable', () => {
+      var emitter;
+      var pipe;
+      var ref;
+      var message = new Object();
+
+      beforeEach(() => {
+        emitter = new EventEmitter();
+        ref = new SpyChangeDetectorRef();
+        pipe = new AsyncPipe(ref);
+      });
+
+      describe("transform", () => {
+        it("should return null when subscribing to an observable",
+           () => { expect(pipe.transform(emitter)).toBe(null); });
+
+        it("should return the latest available value wrapped",
+           inject([AsyncTestCompleter], (async) => {
+             pipe.transform(emitter);
+
+             ObservableWrapper.callNext(emitter, message);
+
+             TimerWrapper.setTimeout(() => {
+               expect(pipe.transform(emitter)).toEqual(new WrappedValue(message));
+               async.done();
+             }, 0)
+           }));
+
+
+        it("should return same value when nothing has changed since the last call",
+           inject([AsyncTestCompleter], (async) => {
+             pipe.transform(emitter);
+             ObservableWrapper.callNext(emitter, message);
+
+             TimerWrapper.setTimeout(() => {
+               pipe.transform(emitter);
+               expect(pipe.transform(emitter)).toBe(message);
+               async.done();
+             }, 0)
+           }));
+
+        it("should dispose of the existing subscription when subscribing to a new observable",
+           inject([AsyncTestCompleter], (async) => {
+             pipe.transform(emitter);
+
+             var newEmitter = new EventEmitter();
+             expect(pipe.transform(newEmitter)).toBe(null);
+
+             // this should not affect the pipe
+             ObservableWrapper.callNext(emitter, message);
+
+             TimerWrapper.setTimeout(() => {
+               expect(pipe.transform(newEmitter)).toBe(null);
+               async.done();
+             }, 0)
+           }));
+
+        it("should request a change detection check upon receiving a new value",
+           inject([AsyncTestCompleter], (async) => {
+             pipe.transform(emitter);
+             ObservableWrapper.callNext(emitter, message);
+
+             TimerWrapper.setTimeout(() => {
+               expect(ref.spy('requestCheck')).toHaveBeenCalled();
+               async.done();
+             }, 0)
+           }));
+      });
+
+      describe("onDestroy", () => {
+        it("should do nothing when no subscription",
+           () => { expect(() => pipe.onDestroy()).not.toThrow(); });
+
+        it("should dispose of the existing subscription", inject([AsyncTestCompleter], (async) => {
+             pipe.transform(emitter);
+             pipe.onDestroy();
+
+             ObservableWrapper.callNext(emitter, message);
+
+             TimerWrapper.setTimeout(() => {
+               expect(pipe.transform(emitter)).toBe(null);
+               async.done();
+             }, 0)
+           }));
+      });
+    });
+
+    describe("Promise", () => {
+      var message = new Object();
+      var pipe;
+      var completer;
+      var ref;
+      // adds longer timers for passing tests in IE
+      var timer = (!isBlank(DOM) && DOM.getUserAgent().indexOf("Trident") > -1) ? 50 : 0;
+
+      beforeEach(() => {
+        completer = PromiseWrapper.completer();
+        ref = new SpyChangeDetectorRef();
+        pipe = new AsyncPipe(ref);
+      });
+
+      describe("transform", () => {
+        it("should return null when subscribing to a promise",
+           () => { expect(pipe.transform(completer.promise)).toBe(null); });
+
+        it("should return the latest available value", inject([AsyncTestCompleter], (async) => {
+             pipe.transform(completer.promise);
+
+             completer.resolve(message);
+
+             TimerWrapper.setTimeout(() => {
+               expect(pipe.transform(completer.promise)).toEqual(new WrappedValue(message));
+               async.done();
+             }, timer)
+           }));
+
+        it("should return unwrapped value when nothing has changed since the last call",
+           inject([AsyncTestCompleter], (async) => {
+             pipe.transform(completer.promise);
+             completer.resolve(message);
+
+             TimerWrapper.setTimeout(() => {
+               pipe.transform(completer.promise);
+               expect(pipe.transform(completer.promise)).toBe(message);
+               async.done();
+             }, timer)
+           }));
+
+        it("should dispose of the existing subscription when subscribing to a new promise",
+           inject([AsyncTestCompleter], (async) => {
+             pipe.transform(completer.promise);
+
+             var newCompleter = PromiseWrapper.completer();
+             expect(pipe.transform(newCompleter.promise)).toBe(null);
+
+             // this should not affect the pipe, so it should return WrappedValue
+             completer.resolve(message);
+
+             TimerWrapper.setTimeout(() => {
+               expect(pipe.transform(newCompleter.promise)).toBe(null);
+               async.done();
+             }, timer)
+           }));
+
+        it("should request a change detection check upon receiving a new value",
+           inject([AsyncTestCompleter], (async) => {
+             pipe.transform(completer.promise);
+             completer.resolve(message);
+
+             TimerWrapper.setTimeout(() => {
+               expect(ref.spy('requestCheck')).toHaveBeenCalled();
+               async.done();
+             }, timer)
+           }));
+
+        describe("onDestroy", () => {
+          it("should do nothing when no source",
+             () => { expect(() => pipe.onDestroy()).not.toThrow(); });
+
+          it("should dispose of the existing source", inject([AsyncTestCompleter], (async) => {
+               pipe.transform(completer.promise);
+               expect(pipe.transform(completer.promise)).toBe(null);
+               completer.resolve(message)
+
+
+                   TimerWrapper.setTimeout(() => {
+                     expect(pipe.transform(completer.promise)).toEqual(new WrappedValue(message));
+                     pipe.onDestroy();
+                     expect(pipe.transform(completer.promise)).toBe(null);
+                     async.done();
+                   }, timer);
+             }));
+        });
+      });
+    });
+
+    describe('null', () => {
+      it('should return null when given null', () => {
+        var pipe = new AsyncPipe(null);
+        expect(pipe.transform(null, [])).toEqual(null);
+      });
+    });
+
+    describe('other types', () => {
+      it('should throw when given an invalid object', () => {
+        var pipe = new AsyncPipe(null);
+        expect(() => pipe.transform(<any>"some bogus object", [])).toThrowError();
+      });
+    });
+  });
+}

modules/angular2/test/change_detection/pipes/observable_pipe_spec.ts

@@ -1,125 +0,0 @@
-import {
-  ddescribe,
-  describe,
-  it,
-  iit,
-  xit,
-  expect,
-  beforeEach,
-  afterEach,
-  AsyncTestCompleter,
-  inject,
-  proxy,
-  SpyObject
-} from 'angular2/test_lib';
-
-import {IMPLEMENTS} from 'angular2/src/facade/lang';
-import {WrappedValue} from 'angular2/src/change_detection/pipes/pipe';
-import {ObservablePipe} from 'angular2/src/change_detection/pipes/observable_pipe';
-import {ChangeDetectorRef} from 'angular2/src/change_detection/change_detector_ref';
-import {EventEmitter, ObservableWrapper, TimerWrapper} from 'angular2/src/facade/async';
-
-export function main() {
-  describe("ObservablePipe", () => {
-    var emitter;
-    var pipe;
-    var ref;
-    var message = new Object();
-
-    beforeEach(() => {
-      emitter = new EventEmitter();
-      ref = new SpyChangeDetectorRef();
-      pipe = new ObservablePipe(ref);
-    });
-
-    describe("supports", () => {
-      it("should support observables", () => { expect(pipe.supports(emitter)).toBe(true); });
-
-      it("should not support other objects", () => {
-        expect(pipe.supports("string")).toBe(false);
-        expect(pipe.supports(null)).toBe(false);
-      });
-    });
-
-    describe("transform", () => {
-      it("should return null when subscribing to an observable",
-         () => { expect(pipe.transform(emitter)).toBe(null); });
-
-      it("should return the latest available value wrapped",
-         inject([AsyncTestCompleter], (async) => {
-           pipe.transform(emitter);
-
-           ObservableWrapper.callNext(emitter, message);
-
-           TimerWrapper.setTimeout(() => {
-             expect(pipe.transform(emitter)).toEqual(new WrappedValue(message));
-             async.done();
-           }, 0)
-         }));
-
-
-      it("should return same value when nothing has changed since the last call",
-         inject([AsyncTestCompleter], (async) => {
-           pipe.transform(emitter);
-           ObservableWrapper.callNext(emitter, message);
-
-           TimerWrapper.setTimeout(() => {
-             pipe.transform(emitter);
-             expect(pipe.transform(emitter)).toBe(message);
-             async.done();
-           }, 0)
-         }));
-
-      it("should dispose of the existing subscription when subscribing to a new observable",
-         inject([AsyncTestCompleter], (async) => {
-           pipe.transform(emitter);
-
-           var newEmitter = new EventEmitter();
-           expect(pipe.transform(newEmitter)).toBe(null);
-
-           // this should not affect the pipe
-           ObservableWrapper.callNext(emitter, message);
-
-           TimerWrapper.setTimeout(() => {
-             expect(pipe.transform(newEmitter)).toBe(null);
-             async.done();
-           }, 0)
-         }));
-
-      it("should request a change detection check upon receiving a new value",
-         inject([AsyncTestCompleter], (async) => {
-           pipe.transform(emitter);
-           ObservableWrapper.callNext(emitter, message);
-
-           TimerWrapper.setTimeout(() => {
-             expect(ref.spy('requestCheck')).toHaveBeenCalled();
-             async.done();
-           }, 0)
-         }));
-    });
-
-    describe("onDestroy", () => {
-      it("should do nothing when no subscription",
-         () => { expect(() => pipe.onDestroy()).not.toThrow(); });
-
-      it("should dispose of the existing subscription", inject([AsyncTestCompleter], (async) => {
-           pipe.transform(emitter);
-           pipe.onDestroy();
-
-           ObservableWrapper.callNext(emitter, message);
-
-           TimerWrapper.setTimeout(() => {
-             expect(pipe.transform(emitter)).toBe(null);
-             async.done();
-           }, 0)
-         }));
-    });
-  });
-}
-
-@proxy
-@IMPLEMENTS(ChangeDetectorRef)
-class SpyChangeDetectorRef extends SpyObject {
-  constructor() { super(ChangeDetectorRef); }
-  noSuchMethod(m) { return super.noSuchMethod(m) }
-}

modules/angular2/test/change_detection/pipes/promise_pipe_spec.ts

@@ -1,127 +0,0 @@
-import {
-  ddescribe,
-  describe,
-  it,
-  iit,
-  xit,
-  expect,
-  beforeEach,
-  afterEach,
-  AsyncTestCompleter,
-  inject,
-  proxy,
-  SpyObject
-} from 'angular2/test_lib';
-import {IMPLEMENTS, isBlank} from 'angular2/src/facade/lang';
-import {PromisePipe} from 'angular2/src/change_detection/pipes/promise_pipe';
-import {WrappedValue} from 'angular2/src/change_detection/pipes/pipe';
-import {ChangeDetectorRef} from 'angular2/src/change_detection/change_detector_ref';
-import {PromiseWrapper, TimerWrapper} from 'angular2/src/facade/async';
-import {DOM} from 'angular2/src/dom/dom_adapter';
-
-export function main() {
-  describe("PromisePipe", () => {
-    var message = new Object();
-    var pipe;
-    var completer;
-    var ref;
-    // adds longer timers for passing tests in IE
-    var timer = (!isBlank(DOM) && DOM.getUserAgent().indexOf("Trident") > -1) ? 50 : 0;
-
-    beforeEach(() => {
-      completer = PromiseWrapper.completer();
-      ref = new SpyChangeDetectorRef();
-      pipe = new PromisePipe(ref);
-    });
-
-    describe("supports", () => {
-      it("should support promises", () => { expect(pipe.supports(completer.promise)).toBe(true); });
-
-      it("should not support other objects", () => {
-        expect(pipe.supports("string")).toBe(false);
-        expect(pipe.supports(null)).toBe(false);
-      });
-    });
-
-    describe("transform", () => {
-      it("should return null when subscribing to a promise",
-         () => { expect(pipe.transform(completer.promise)).toBe(null); });
-
-      it("should return the latest available value", inject([AsyncTestCompleter], (async) => {
-           pipe.transform(completer.promise);
-
-           completer.resolve(message);
-
-           TimerWrapper.setTimeout(() => {
-             expect(pipe.transform(completer.promise)).toEqual(new WrappedValue(message));
-             async.done();
-           }, timer)
-         }));
-
-      it("should return unwrapped value when nothing has changed since the last call",
-         inject([AsyncTestCompleter], (async) => {
-           pipe.transform(completer.promise);
-           completer.resolve(message);
-
-           TimerWrapper.setTimeout(() => {
-             pipe.transform(completer.promise);
-             expect(pipe.transform(completer.promise)).toBe(message);
-             async.done();
-           }, timer)
-         }));
-
-      it("should dispose of the existing subscription when subscribing to a new promise",
-         inject([AsyncTestCompleter], (async) => {
-           pipe.transform(completer.promise);
-
-           var newCompleter = PromiseWrapper.completer();
-           expect(pipe.transform(newCompleter.promise)).toBe(null);
-
-           // this should not affect the pipe, so it should return WrappedValue
-           completer.resolve(message);
-
-           TimerWrapper.setTimeout(() => {
-             expect(pipe.transform(newCompleter.promise)).toBe(null);
-             async.done();
-           }, timer)
-         }));
-
-      it("should request a change detection check upon receiving a new value",
-         inject([AsyncTestCompleter], (async) => {
-           pipe.transform(completer.promise);
-           completer.resolve(message);
-
-           TimerWrapper.setTimeout(() => {
-             expect(ref.spy('requestCheck')).toHaveBeenCalled();
-             async.done();
-           }, timer)
-         }));
-
-      describe("onDestroy", () => {
-        it("should do nothing when no source",
-           () => { expect(() => pipe.onDestroy()).not.toThrow(); });
-
-        it("should dispose of the existing source", inject([AsyncTestCompleter], (async) => {
-             pipe.transform(completer.promise);
-             expect(pipe.transform(completer.promise)).toBe(null);
-             completer.resolve(message)
-
-
-                 TimerWrapper.setTimeout(() => {
-                   expect(pipe.transform(completer.promise)).toEqual(new WrappedValue(message));
-                   pipe.onDestroy();
-                   expect(pipe.transform(completer.promise)).toBe(null);
-                   async.done();
-                 }, timer);
-           }));
-      });
-    });
-  });
-}
-
-@proxy
-@IMPLEMENTS(ChangeDetectorRef)
-class SpyChangeDetectorRef extends SpyObject {
-  constructor() { super(ChangeDetectorRef); }
-  noSuchMethod(m) { return super.noSuchMethod(m) }
-}