Angular 11:单元测试HttpInterceptor -无法让catchError在测试中工作

import { TestBed } from '@angular/core/testing';
import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
import { HttpClient, HTTP_INTERCEPTORS, HttpResponse } from '@angular/common/http';
import { catchError } from 'rxjs/operators';

import { MyHttpInterceptor } from './my-http-interceptor';

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

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

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

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

  it('should handle error using catchError', () => {
    const mockErrorResponse = { status: 400, statusText: 'Bad Request' };
    const data = 'Invalid request parameters';

    httpClient.get('/api/data')
      .pipe(catchError((error) => {
        expect(error.status).toBe(400);
        expect(error.statusText).toBe('Bad Request');
        expect(error.error).toBe('Invalid request parameters');
        return [];
      }))
      .subscribe((response) => {
        expect(response).toEqual([]);
      });

    const req = httpMock.expectOne('/api/data');
    req.flush(data, mockErrorResponse);
  });
});