aegoncalc/frontend/src/app/calculator.service.spec.ts

import { TestBed } from '@angular/core/testing';

import { CalculatorService } from './calculator.service';
import {HttpClientTestingModule, HttpTestingController} from "@angular/common/http/testing";
import {HttpClient} from "@angular/common/http";

describe('CalculatorService', () => {
  let service: CalculatorService;
  let httpClient : HttpClient;
  let httpTestingController : HttpTestingController;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
    });

    httpClient = TestBed.inject(HttpClient);
    httpTestingController = TestBed.inject(HttpTestingController);
    service = TestBed.inject(CalculatorService);
  });

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

  it('should be created', () => {
    expect(service).toBeTruthy();
  });

  it('should return ', () => {
    let mockResponse : number = 3;

    service.calculate('add', 1, 2).subscribe(
      r => expect(r.body).toEqual(mockResponse, 'should return expected number'),
      fail
    );

    const req = httpTestingController.expectOne('/api/numbers/1/add/2');
    expect(req.request.method).toEqual('GET');

    req.flush(mockResponse);
  });

});