angular-cn/modules/@angular/core/testing/component_fixture.ts

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/**
* @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 {ChangeDetectorRef, ComponentRef, DebugElement, ElementRef, NgZone, getDebugNode} from '../index';
import {BaseException} from '../src/facade/exceptions';
import {scheduleMicroTask} from '../src/facade/lang';
import {tick} from './fake_async';
/**
* Fixture for debugging and testing a component.
*
* @stable
*/
export class ComponentFixture<T> {
/**
* The DebugElement associated with the root element of this component.
*/
debugElement: DebugElement;
/**
* The instance of the root component class.
*/
componentInstance: T;
/**
* The native element at the root of the component.
*/
nativeElement: any;
/**
* The ElementRef for the element at the root of the component.
*/
elementRef: ElementRef;
/**
* The ComponentRef for the component
*/
componentRef: ComponentRef<T>;
/**
* The ChangeDetectorRef for the component
*/
changeDetectorRef: ChangeDetectorRef;
/**
* The NgZone in which this component was instantiated.
*/
ngZone: NgZone;
private _autoDetect: boolean;
private _isStable: boolean = true;
private _resolve: (result: any) => void;
private _promise: Promise<any> = null;
private _onUnstableSubscription: any /** TODO #9100 */ = null;
private _onStableSubscription: any /** TODO #9100 */ = null;
private _onMicrotaskEmptySubscription: any /** TODO #9100 */ = null;
private _onErrorSubscription: any /** TODO #9100 */ = null;
constructor(componentRef: ComponentRef<T>, ngZone: NgZone, autoDetect: boolean) {
this.changeDetectorRef = componentRef.changeDetectorRef;
this.elementRef = componentRef.location;
this.debugElement = <DebugElement>getDebugNode(this.elementRef.nativeElement);
this.componentInstance = componentRef.instance;
this.nativeElement = this.elementRef.nativeElement;
this.componentRef = componentRef;
this.ngZone = ngZone;
this._autoDetect = autoDetect;
if (ngZone != null) {
this._onUnstableSubscription =
ngZone.onUnstable.subscribe({next: () => { this._isStable = false; }});
this._onMicrotaskEmptySubscription = ngZone.onMicrotaskEmpty.subscribe({
next: () => {
if (this._autoDetect) {
// Do a change detection run with checkNoChanges set to true to check
// there are no changes on the second run.
this.detectChanges(true);
}
}
});
this._onStableSubscription = ngZone.onStable.subscribe({
next: () => {
this._isStable = true;
// Check whether there is a pending whenStable() completer to resolve.
if (this._promise !== null) {
// If so check whether there are no pending macrotasks before resolving.
// Do this check in the next tick so that ngZone gets a chance to update the state of
// pending macrotasks.
scheduleMicroTask(() => {
if (!this.ngZone.hasPendingMacrotasks) {
if (this._promise !== null) {
this._resolve(true);
this._resolve = null;
this._promise = null;
}
}
});
}
}
});
this._onErrorSubscription =
ngZone.onError.subscribe({next: (error: any) => { throw error; }});
}
}
private _tick(checkNoChanges: boolean) {
this.changeDetectorRef.detectChanges();
if (checkNoChanges) {
this.checkNoChanges();
}
}
/**
* Trigger a change detection cycle for the component.
*/
detectChanges(checkNoChanges: boolean = true): void {
if (this.ngZone != null) {
// Run the change detection inside the NgZone so that any async tasks as part of the change
// detection are captured by the zone and can be waited for in isStable.
this.ngZone.run(() => { this._tick(checkNoChanges); });
} else {
// Running without zone. Just do the change detection.
this._tick(checkNoChanges);
}
}
/**
* Do a change detection run to make sure there were no changes.
*/
checkNoChanges(): void { this.changeDetectorRef.checkNoChanges(); }
/**
* Set whether the fixture should autodetect changes.
*
* Also runs detectChanges once so that any existing change is detected.
*/
autoDetectChanges(autoDetect: boolean = true) {
if (this.ngZone == null) {
throw new BaseException('Cannot call autoDetectChanges when ComponentFixtureNoNgZone is set');
}
this._autoDetect = autoDetect;
this.detectChanges();
}
/**
* Return whether the fixture is currently stable or has async tasks that have not been completed
* yet.
*/
isStable(): boolean { return this._isStable && !this.ngZone.hasPendingMacrotasks; }
/**
* Get a promise that resolves when the fixture is stable.
*
* This can be used to resume testing after events have triggered asynchronous activity or
* asynchronous change detection.
*/
whenStable(): Promise<any> {
if (this.isStable()) {
return Promise.resolve(false);
} else if (this._promise !== null) {
return this._promise;
} else {
this._promise = new Promise(res => { this._resolve = res; });
return this._promise;
}
}
/**
* Trigger component destruction.
*/
destroy(): void {
this.componentRef.destroy();
if (this._onUnstableSubscription != null) {
this._onUnstableSubscription.unsubscribe();
this._onUnstableSubscription = null;
}
if (this._onStableSubscription != null) {
this._onStableSubscription.unsubscribe();
this._onStableSubscription = null;
}
if (this._onMicrotaskEmptySubscription != null) {
this._onMicrotaskEmptySubscription.unsubscribe();
this._onMicrotaskEmptySubscription = null;
}
if (this._onErrorSubscription != null) {
this._onErrorSubscription.unsubscribe();
this._onErrorSubscription = null;
}
}
}