IAfanasovMob

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

IAfanasovMob

it(`should add Accept header with value 'application/vnd.github.v3.star+json'
    when requested https://api.github.com/*`, () => {
  client.get('https://api.github.com/anything').subscribe();

  const requests = httpMock.match({ method: 'get' });

  expect(requests[0].request.headers.get('Accept'))
    .toEqual('application/vnd.github.v3.star+json');
});

IAfanasovMob

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


@Injectable()
export class GitHubApiVersionInterceptor implements HttpInterceptor {

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    if (req.url.startsWith('https://api.github.com/')) {