Angular2 - http 调用代码覆盖率

## 使用Angular 2进行HTTP调用代码覆盖率

javascript
// karma.conf.js
module.exports = function(config) {
  config.set({
    // 其他配置项...
    reporters: ['progress', 'coverage'],
    coverageReporter: {
      dir: 'coverage/',
      reporters: [
        { type: 'html', subdir: 'report-html' },
        { type: 'lcov', subdir: 'report-lcov' },
        { type: 'text-summary' },
      ],
    },
  });
};

typescript
// http.service.ts
import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
@Injectable({
  providedIn: 'root',
})
export class HttpService {
  constructor(private http: HttpClient) {}
  fetchData(): Observable {
    return this.http.get('https://jsonplaceholder.typicode.com/todos/1');
  }
}

typescript
// http.service.spec.ts
import { TestBed, inject } from '@angular/core/testing';
import { HttpClientTestingModule } from '@angular/common/http/testing';
import { HttpService } from './http.service';
describe('HttpService', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [HttpService],
    });
  });
  it('should be created', inject([HttpService], (service: HttpService) => {
    expect(service).toBeTruthy();
  }));
  it('should fetch data successfully', inject([HttpService], (service: HttpService) => {
    service.fetchData().subscribe((data) => {
      expect(data).toBeTruthy();
    });
  }));
  it('should handle errors properly', inject([HttpService], (service: HttpService) => {
    // 模拟一个失败的HTTP调用
    spyOn(service['http'], 'get').and.returnValue(
      new Observable((observer) => {
        observer.error('Error occurred');
      })
    );
    service.fetchData().subscribe(
      () => {},
      (error) => {
        expect(error).toEqual('Error occurred');
      }
    );
  }));
});

bash
ng test --code-coverage