angular-docs-cn/modules/@angular/core/testing/fake_async.ts

128 lines
3.4 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {BaseException} from '../index';
let _FakeAsyncTestZoneSpecType = (Zone as any /** TODO #9100 */)['FakeAsyncTestZoneSpec'];
let _fakeAsyncZone: Zone = null;
let _fakeAsyncTestZoneSpec: any = null;
/**
* Clears out the shared fake async zone for a test.
* To be called in a global `beforeEach`.
*
* @experimental
*/
export function resetFakeAsyncZone() {
_fakeAsyncZone = null;
_fakeAsyncTestZoneSpec = null;
}
let _inFakeAsyncCall = false;
/**
* Wraps a function to be executed in the fakeAsync zone:
* - microtasks are manually executed by calling `flushMicrotasks()`,
* - timers are synchronous, `tick()` simulates the asynchronous passage of time.
*
* If there are any pending timers at the end of the function, an exception will be thrown.
*
* Can be used to wrap inject() calls.
*
* ## Example
*
* {@example testing/ts/fake_async.ts region='basic'}
*
* @param fn
* @returns {Function} The function wrapped to be executed in the fakeAsync zone
*
* @experimental
*/
export function fakeAsync(fn: Function): (...args: any[]) => any {
return function(...args: any[] /** TODO #9100 */) {
if (_inFakeAsyncCall) {
throw new BaseException('fakeAsync() calls can not be nested');
}
_inFakeAsyncCall = true;
try {
if (!_fakeAsyncZone) {
if (Zone.current.get('FakeAsyncTestZoneSpec') != null) {
throw new BaseException('fakeAsync() calls can not be nested');
}
_fakeAsyncTestZoneSpec = new _FakeAsyncTestZoneSpecType();
_fakeAsyncZone = Zone.current.fork(_fakeAsyncTestZoneSpec);
}
let res = _fakeAsyncZone.run(() => {
let res = fn(...args);
flushMicrotasks();
return res;
});
if (_fakeAsyncTestZoneSpec.pendingPeriodicTimers.length > 0) {
throw new BaseException(
`${_fakeAsyncTestZoneSpec.pendingPeriodicTimers.length} ` +
`periodic timer(s) still in the queue.`);
}
if (_fakeAsyncTestZoneSpec.pendingTimers.length > 0) {
throw new BaseException(
`${_fakeAsyncTestZoneSpec.pendingTimers.length} timer(s) still in the queue.`);
}
return res;
} finally {
_inFakeAsyncCall = false;
}
};
}
function _getFakeAsyncZoneSpec(): any {
if (_fakeAsyncTestZoneSpec == null) {
throw new Error('The code should be running in the fakeAsync zone to call this function');
}
return _fakeAsyncTestZoneSpec;
}
/**
* Simulates the asynchronous passage of time for the timers in the fakeAsync zone.
*
* The microtasks queue is drained at the very start of this function and after any timer callback
* has been executed.
*
* ## Example
*
* {@example testing/ts/fake_async.ts region='basic'}
*
* @experimental
*/
export function tick(millis: number = 0): void {
_getFakeAsyncZoneSpec().tick(millis);
}
/**
* Discard all remaining periodic tasks.
*
* @experimental
*/
export function discardPeriodicTasks(): void {
let zoneSpec = _getFakeAsyncZoneSpec();
let pendingTimers = zoneSpec.pendingPeriodicTimers;
zoneSpec.pendingPeriodicTimers.length = 0;
}
/**
* Flush any pending microtasks.
*
* @experimental
*/
export function flushMicrotasks(): void {
_getFakeAsyncZoneSpec().flushMicrotasks();
}