测试angular http拦截器-在intercept返回之前调用expect

import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler, HttpEvent } from '@angular/common/http';

@Injectable()
export class MyInterceptor implements HttpInterceptor {
  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    // 在intercept返回之前调用expect
    console.log('expect called before intercept returns');
    return next.handle(req);
  }
}

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

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

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

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

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

  it('should call expect before intercept returns', inject([HttpClient], (http: HttpClient) => {
    http.get('/api/data').subscribe();

    const req = httpMock.expectOne('/api/data');
    expect(req.request.method).toBe('GET');

    // 断言在intercept返回之前调用expect
    console.log('expect called before intercept returns');
  }));

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