单元测试Angular HTTP拦截器

import { TestBed, inject } from '@angular/core/testing';
import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';

import { MyInterceptor } from './my-interceptor';

describe('MyInterceptor', () => {
  let httpMock: HttpTestingController;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [
        MyInterceptor,
        {
          provide: HTTP_INTERCEPTORS,
          useClass: MyInterceptor,
          multi: true
        }
      ]
    });

    httpMock = TestBed.inject(HttpTestingController);
  });

  afterEach(() => {
    httpMock.verify();
  });

  it('should add authorization token to request headers', inject([HttpClient], (http: HttpClient) => {
    const token = 'my-auth-token';

    http.get('/api/data').subscribe(response => {
      expect(response).toBeTruthy();
    });

    const httpRequest = httpMock.expectOne('/api/data');
    expect(httpRequest.request.headers.has('Authorization')).toBeTruthy();
    expect(httpRequest.request.headers.get('Authorization')).toBe(`Bearer ${token}`);

    httpRequest.flush({ data: 'test' });
  }));

  it('should handle error response', inject([HttpClient], (http: HttpClient) => {
    http.get('/api/data').subscribe(
      response => {
        // This should not be called
        expect(true).toBeFalsy();
      },
      error => {
        expect(error).toBeTruthy();
      }
    );

    const httpRequest = httpMock.expectOne('/api/data');
    httpRequest.error(new ErrorEvent('Network error'));

    httpMock.verify();
  }));
});