test(toArray): add basic type definition test

spec/helpers/test-helper.ts

@@ -17,6 +17,7 @@ global.hot = marbleHelpers.hot;
 global.time = marbleHelpers.time;
 global.expectObservable = marbleHelpers.expectObservable;
 global.expectSubscriptions = marbleHelpers.expectSubscriptions;
+global.type = type;
 
 //amending type definition of jasmine which seems doesn't have this
 export interface DoneSignature {
@@ -77,6 +78,11 @@ if (!global.asDiagram) {
  global.asDiagram = asDiagram;
 }
 
+export function type(assertion: Function): void {
+ //intentionally does not execute to avoid unexpected side effect occurs by subscription,
+ //or infinite source. Suffecient to check build time only.
+}
+
 export function lowerCaseO<T>(...args): Rx.Observable<T> {
  const values = [].slice.apply(arguments);
 
@@ -154,4 +160,4 @@ global.__root__ = root;
 
 afterEach(function () {
  global.rxTestScheduler = null;
-});
+});

spec/operators/toArray-spec.ts

@@ -1,5 +1,5 @@
 import * as Rx from '../../dist/cjs/Rx';
-declare const {hot, cold, asDiagram, expectObservable, expectSubscriptions};
+declare const {hot, cold, asDiagram, expectObservable, expectSubscriptions, type};
 
 const Observable = Rx.Observable;
 
@@ -101,4 +101,12 @@ describe('Observable.prototype.toArray', () => {
  expectObservable(e1.toArray()).toBe(expected);
  expectSubscriptions(e1.subscriptions).toBe(e1subs);
  });
+
+ type(() => {
+ const typeValue = {
+ val: 3
+ };
+
+ Observable.of(typeValue).toArray().subscribe(x => { x[0].val.toString(); });
+ });
 });