在测试中使用 fakeAsync 会导致 Angular 4 和 Zone.js 出错

Question

I'm using Angular 4.3.1 and zone.js 0.8.14 and I'm running my tests, with karma and webpack and came across this weird error in my tests whenever I'm using fakeAsync and tick for time-related tests.

The test case:

it('should call the function which is given as parameter', fakeAsync(() => {
  autoRefreshService.start();
  expect(spyFn).not.toHaveBeenCalled();
  tick(1);
  expect(spyFn).toHaveBeenCalled();
}));

The test invoking file:

require('core-js/es6');
require('core-js/es7/reflect');
require('zone.js/dist/zone');
require('zone.js/dist/long-stack-trace-zone');
require('zone.js/dist/proxy');
require('zone.js/dist/sync-test');
require('zone.js/dist/jasmine-patch');
require('zone.js/dist/async-test');
require('zone.js/dist/fake-async-test');
import { TestBed } from '@angular/core/testing';
import {
    BrowserDynamicTestingModule,
    platformBrowserDynamicTesting,
} from '@angular/platform-browser-dynamic/testing';

TestBed.initTestEnvironment(BrowserDynamicTestingModule, platformBrowserDynamicTesting());
const context = (require as any).context('./', true, /\.spec\.ts$/);
context.keys().map(context);

And the error I'm getting is:

Chrome 59.0.3071 (Mac OS X 10.12.5) CallbackRepeaterService start should not start if no callback set FAILED
    TypeError: Right-hand side of 'instanceof' is not an object
        at Object.<anonymous> (src/test.ts:25139:49)
        at ZoneDelegate.invoke (src/test.ts:86299:26)
        at ProxyZoneSpec.onInvoke (src/test.ts:88697:39)
        at ZoneDelegate.invoke (src/test.ts:86298:32)
        at Zone.run (src/test.ts:86049:43)
        at Object.<anonymous> (src/test.ts:88992:34)
        at ZoneQueueRunner.jasmine.QueueRunner.ZoneQueueRunner.execute (src/test.ts:89020:42)

The error message must be related to fakeAsync , because if I remove it, it doesn't complain.

What could be the issue here?

Answer 1

So the problem was I needed to add import 'zone.js/dist/fake-async-test'; to the testing entry file.