fix(facade): Make PromiseWrapper#all semantics equivalent

The semantics between ES6 `Promise#all` and Dart's `Future#wait` are
different for values that are not `Promise`/`Future`s. In ES6,
non-`Promise` values are immediately completed to their current value.
In Dart, non-`Future` values cause an error.

Updated Dart's `PromiseWrapper#all` implementation to conform to the ES6
spec.

modules/angular2/src/facade/async.dart

@@ -9,9 +9,12 @@ class PromiseWrapper {
   static Future reject(obj, stackTrace) => new Future.error(obj,
       stackTrace != null ? stackTrace : obj is Error ? obj.stackTrace : null);
 
-  static Future<List> all(List<Future> promises) => Future.wait(promises);
+  static Future<List> all(List<dynamic> promises) {
+    return Future
+        .wait(promises.map((p) => p is Future ? p : new Future.value(p)));
+  }
 
-  static Future then(Future promise, success(value), Function onError) {
+  static Future then(Future promise, success(value), [Function onError]) {
     if (success == null) return promise.catchError(onError);
     return promise.then(success, onError: onError);
   }

modules/angular2/src/facade/async.ts

@@ -18,13 +18,13 @@ export class PromiseWrapper {
     return promise.catch(onError);
   }
 
-  static all(promises: List<Promise<any>>): Promise<any> {
+  static all(promises: List<any>): Promise<any> {
     if (promises.length == 0) return Promise.resolve([]);
     return Promise.all(promises);
   }
 
   static then<T>(promise: Promise<T>, success: (value: any) => T | Thenable<T>,
-                 rejection: (error: any, stack?: any) => T | Thenable<T>): Promise<T> {
+                 rejection?: (error: any, stack?: any) => T | Thenable<T>): Promise<T> {
     return promise.then(success, rejection);
   }
 

modules/angular2/test/facade/async_spec.ts

@@ -14,6 +14,7 @@ import {
 } from 'angular2/test_lib';
 
 import {ObservableWrapper, EventEmitter, PromiseWrapper} from 'angular2/src/facade/async';
+import {ListWrapper} from 'angular2/src/facade/collection';
 
 export function main() {
   describe('EventEmitter', () => {
@@ -62,4 +63,45 @@ export function main() {
     // should call dispose on the subscription on throw
     // should call dispose on the subscription on return
   });
-}
+
+  // See ECMAScript 6 Spec 25.4.4.1
+  describe("PromiseWrapper", () => {
+    describe("#all", () => {
+      it("should combine lists of Promises", inject([AsyncTestCompleter], (async) => {
+           var one = PromiseWrapper.completer();
+           var two = PromiseWrapper.completer();
+
+           var all = PromiseWrapper.all([one.promise, two.promise]);
+           var allCalled = false;
+
+           PromiseWrapper.then(one.promise, (_) => {
+             expect(allCalled).toBe(false);
+             two.resolve('two');
+           });
+
+           PromiseWrapper.then(all, (_) => {
+             allCalled = true;
+             async.done();
+           });
+
+           one.resolve('one');
+         }));
+
+      ListWrapper.forEach([null, true, false, 10, 'thing', {}, []], (abruptCompletion) => {
+        it(`should treat "${abruptCompletion}" as an "abrupt completion"`,
+           inject([AsyncTestCompleter], (async) => {
+             var one = PromiseWrapper.completer();
+
+             var all = PromiseWrapper.all([one.promise, abruptCompletion]);
+
+             PromiseWrapper.then(all, (val) => {
+               expect(val[1]).toEqual(abruptCompletion);
+               async.done();
+             });
+
+             one.resolve('one');
+           }));
+      });
+    });
+  });
+}