test(fromPromise): ensure Observables can be created from other promi…

…se implementations

spec/observables/from-promise-spec.ts

@@ -72,6 +72,26 @@ describe('Observable.fromPromise', () => {
  });
  });
 
+ it('should accept PromiseLike object for interoperability', (done: MochaDone) => {
+ class CustomPromise<T> implements PromiseLike<T> {
+ constructor(private promise: PromiseLike<T>) {
+ }
+ then(onFulfilled?: ((value: T) => (PromiseLike<T> | T)) | any | any,
+ onRejected?: ((reason: any) => (PromiseLike<T> | T)) | any | any): PromiseLike<T> {
+ return new CustomPromise(this.promise.then(onFulfilled, onRejected));
+ };
+ }
+ const promise = new CustomPromise(Promise.resolve(42));
+ Observable.fromPromise(promise)
+ .subscribe(
+ (x: number) => { expect(x).to.equal(42); },
+ () => {
+ done(new Error('should not be called'));
+ }, () => {
+ done();
+ });
+ });
+
  it('should emit a value from a resolved promise on a separate scheduler', (done: MochaDone) => {
  const promise = Promise.resolve(42);
  Observable.fromPromise(promise, Rx.Scheduler.asap)