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我想为使用Firestore的组件编写单元测试,并且我遇到了Firebase集合嘲讽的问题。在角度TestBed中嘲讽Firestore集合
SUT
export class TobjectsListComponent implements OnInit {
...
constructor(private db: AngularFirestore) {
this.tobjectDatabase = new TobjectDatabase(db);
}
...
}
export class TobjectDatabase {
/** Stream that emits whenever the data has been modified. */
dataChange: BehaviorSubject<TObject[]> = new BehaviorSubject<TObject[]>([]);
get data(): TObject[] { return this.dataChange.value; }
constructor(private db: AngularFirestore) {
this.db.collection<TObject>('tobjects').valueChanges()
.subscribe(data => { this.dataChange.next(data); });
}
}
TEST
class AngularFirestoreMock extends AngularFirestore {
public collection<TObject>(name: string, queryFn?: QueryFn): AngularFirestoreCollection<TObject> {
const ref = this.firestore.collection('tobjects');
if (!queryFn) { queryFn = (ref) => ref; }
return new AngularFirestoreCollection<TObject>(ref, queryFn(ref));
}
}
describe('TobjectListComponent',() => {
let component: TobjectsListComponent;
let fixture: ComponentFixture<TobjectsListComponent>;
beforeEach(async(() => {
TestBed.configureTestingModule({
imports: [MaterialModule],
declarations: [TobjectsListComponent],
providers: [{ "provide": AngularFirestore, "useValue": AngularFirestoreMock }],
schemas: [CUSTOM_ELEMENTS_SCHEMA]
})
.compileComponents();
}));
beforeEach(() => {
fixture = TestBed.createComponent(TobjectsListComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('should create',() => {
expect(component).toBeTruthy();
});
});
试运行
一旦运行测试,我得到一个错误TypeError: this.db.collection is not a function
从堆栈跟踪信息我可以看到,该错误在这一行中有一个来源,并且字符this.db.**c**ollection<TObject>('tobjects').valueChanges()
在TobjectDatabase
类。
TypeError: this.db.collection is not a function
at new TobjectDatabase (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/src/app/tobjects-admin/tobjects-list/tobjects-list.component.ts:82:13)
at new TobjectsListComponent (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/src/app/tobjects-admin/tobjects-list/tobjects-list.component.ts:24:28)
at createClass (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core.es5.js:10933:1)
at createDirectiveInstance (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core.es5.js:10764:22)
at createViewNodes (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core.es5.js:12212:34)
at createRootView (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core.es5.js:12107:1)
at callWithDebugContext (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core.es5.js:13493:26)
at Object.debugCreateRootView [as createRootView] (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core.es5.js:12810:1)
at ComponentFactory_.webpackJsonp.../../../core/@angular/core.es5.js.ComponentFactory_.create (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core.es5.js:9872:26)
at initComponent (http://localhost:9876/_karma_webpack_/webpack:/C:/git/volago2/node_modules/@angular/core/@angular/core/testing.es5.js:889:1)
怎么了?我怎么能嘲笑这个收藏?