Angular TypeError:无法读取属性';订阅';未定义的(角度单位测试)
我有一个简单的测试,结构如下:Angular TypeError:无法读取属性';订阅';未定义的(角度单位测试),angular,unit-testing,testing,jasmine,karma-jasmine,Angular,Unit Testing,Testing,Jasmine,Karma Jasmine,我有一个简单的测试,结构如下: import { async, ComponentFixture, TestBed } from '@angular/core/testing'; import { BreadcrumbsComponent } from './breadcrumbs.component'; import { RouterTestingModule } from '@angular/router/testing'; import { TranslateLoader, Transla
import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { BreadcrumbsComponent } from './breadcrumbs.component';
import { RouterTestingModule } from '@angular/router/testing';
import { TranslateLoader, TranslateModule, TranslateService } from '@ngx-translate/core';
import { HttpClient } from '@angular/common/http';
import { HttpClientTestingModule } from '@angular/common/http/testing';
import { BreadcrumbsService } from './breadcrumbs.service';
import { multiTranslateHttpLoaderFactory } from 'app/app.component';
fdescribe('BreadcrumbsComponent', () => {
let component: BreadcrumbsComponent;
let translateService: TranslateService;
let fixture: ComponentFixture<BreadcrumbsComponent>;
let translateServiceStub: Partial<TranslateService>;
let translateServiceStub: Partial<TranslateService>;
translateServiceStub = {
getBrowserLang: () => {
return 'de';
},
onLangChange: new EventEmitter(),
};
breadcrumbsServiceStub = {
onUpdateRequest: new Subject(),
updateBreadcrumbs: () => {
}
};
beforeEach((() => {
TestBed.configureTestingModule({
declarations: [BreadcrumbsComponent],
imports: [
RouterTestingModule,
HttpClientTestingModule,
TranslateModule.forRoot({
loader: {
provide: TranslateLoader,
useFactory: multiTranslateHttpLoaderFactory,
deps: [HttpClient]
}
}),
],
providers: [
{provide: TranslateService, useValue: translateServiceStub},
{provide: BreadcrumbsService, useValue: breadcrumbsServiceStub},
]
});
}));
beforeEach(() => {
fixture = TestBed.createComponent(BreadcrumbsComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('should create', () => {
expect(component).toBeTruthy();
});
});
我做错了什么?或有没有办法绕过错误或模拟这一行以便测试通过?我真的不知道如何在测试中模仿这句话。你能试试吗:
import { of } from 'rxjs';
translateServiceStub = {
getBrowserLang: () => {
return 'de';
},
onLangChange: of({
// whatever object is expected
}),
};
您的存根与它的存根不匹配,
onLangChange
确实未定义。如何模拟onLangChange。它是translate服务包的一部分,定义如下:readonly onLangChange:EventEmitter;在我的测试中,我没有一个好主意来模拟它。你模拟它的方式与你模拟TranslateService
,getBrowserLang
的另一部分的方式相同;您定义了一个双重测试作为该服务存根的一部分。要么是一个实际的可观察/事件发射器,要么就是一个具有适当行为的subscribe
方法的东西。我将事件发射器包括在存根中并订阅了它。然而,这也会在IDE中引发一个bug。当你说“IDE中的bug”时,你是什么意思?你的工具真的停止工作了吗?给你一个警告?什么警告?这比明显未定义的东西更糟糕吗?
import { of } from 'rxjs';
translateServiceStub = {
getBrowserLang: () => {
return 'de';
},
onLangChange: of({
// whatever object is expected
}),
};