在角项目中使用jasmine的单元测试订阅方法 [英] Unit testing subscribe method using jasmine in angular project
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问题描述
我正在尝试为具有 subscribe
方法的组件测试 ngOnInit()
方法:
I'm trying to test ngOnInit()
method for the component that has a subscribe
method:
组件:
import { Component, OnInit} from '@angular/core';
import { SharedDataService } from './../services/shared-data.service';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.scss']
})
export class AppComponent implements OnInit {
constructor(private sharedDataService: SharedDataService,) { }
this.subscriptions = [];
ngOnInit() {
this.subscriptions.push(this.sharedDataService.getModel().subscribe(model => {
this.message=model.message
}));
}
}
}
测试套件
import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { XHRBackend } from '@angular/http';
describe('AppComponent Test', () => {
let component: any;
let fixture: ComponentFixture<AppComponent>;
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [AppComponent],
providers: [SharedDataService , { provide: XHRBackend, useClass: MockBackend }]
})
.compileComponents();
}));
beforeEach(() => {
fixture = TestBed.createComponent(AppComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
it('should be created', () => {
expect(component).toBeTruthy();
});
it('test onInit function', () => {
component.ngOnInit();
spyOn(component.subscriptions,"push");
expect(component.subscriptions).toHaveBeenCalledWIth(component.sharedDataService.getModel());
});
});
但抛出错误为无法监视订阅。这是测试订阅方法的过程。请建议。
But throwing error as "cannot spy on subscriptions".Is this is the procedure to test subscribe method. Please suggest.
推荐答案
通过实现如下所示的代码来解决:
Fixed by implementing code as shown below:
- 从'rxjs / Observable'导入导入{Observable};在我的规范文件中
-
为订阅内部的方法创建了一个间谍
- Imported import { Observable } from 'rxjs/Observable'; in my spec file
Created a spy for the method called inside subscription
spyOn( component.subscriptions,push);
const spy = spyOn(sharedDataService,'getModel')。和。
returnValue(Observable.of(订阅方法返回的数据);
3.Call ngOnInit()
3.Call ngOnInit()
4.使用 expect()
方法进行断言
4.Make assertions using expect()
method
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