FunnyGhost

  getFavoriteMovies(): Observable<Movie[]> {
    return of([
      { title: 'Interstellar' } as Movie,
      { title: 'The Green Book' } as Movie,
      { title: 'Dark Knight' } as Movie
    ]);
  }

FunnyGhost

const favoriteUrl = 'test.favorite.com';

export const environment = {
  production: false,
  favoriteUrl
};

FunnyGhost

describe('FavoriteMoviesService', () => {
  let serviceUnderTest: FavoriteMoviesService;
  let http: HttpTestingController;

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

FunnyGhost

export class FavoriteMoviesService {
  constructor(private http: HttpClient) {}

  getFavoriteMovies(): Observable<Movie[]> {
    return this.http.get<Movie[]>(environment.favoriteUrl);
  }
}

FunnyGhost

  it('should throw if the backend returns an error ', () => {
    let bubblesUpTheError = false;
    serviceUnderTest.getFavoriteMovies().subscribe(() => {}, () => (bubblesUpTheError = true));

    const req = http.expectOne(environment.favoriteUrl, 'expected to make a request');
    expect(req.request.method).toEqual('GET');
    req.flush('ERROR', { status: 500, statusText: 'Internal server error' });

    expect(bubblesUpTheError).toBeTruthy();
    http.verify();

FunnyGhost

  it('should fail if the backend returns an error 3 times in a row', done => {
    let bubblesUpTheError = false;
    serviceUnderTest.getFavoriteMovies().subscribe(() => {}, () => (bubblesUpTheError = true);

    const req = http.expectOne(environment.favoriteUrl, 'expected to make an initial request');
    expect(req.request.method).toEqual('GET');
    req.flush('ERROR', { status: 500, statusText: 'Internal server error' });

    const req2 = http.expectOne(environment.favoriteUrl, 'expected to make a second request');
    expect(req2.request.method).toEqual('GET');

FunnyGhost

  getFavoriteMovies(): Observable<Movie[]> {
    return this.http.get<Movie[]>(environment.favoriteUrl).pipe(retry(2));
  }

FunnyGhost

  it('should return the list of favorite movies if the backend returns an error 2 times and the succeds', () => {
    let favoriteMovies: Movie[] = [];
    serviceUnderTest.getFavoriteMovies().subscribe(data => {
      favoriteMovies = data;
    });

    const req = http.expectOne(environment.favoriteUrl, 'expected to make an initial request');
    expect(req.request.method).toEqual('GET');
    req.flush('ERROR', { status: 500, statusText: 'Internal server error' });

FunnyGhost

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';
import { retry } from 'rxjs/operators';
import { environment } from 'src/environments/environment';
import { Movie } from '../movie-list/core/models/movie';

@Injectable()
export class FavoriteMoviesService {
  constructor(private http: HttpClient) {}

FunnyGhost

import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
import { TestBed } from '@angular/core/testing';
import { environment } from 'src/environments/environment';
import { Movie } from '../movie-list/core/models/movie';
import { FavoriteMoviesService } from './favorite-movies.service';

const moviesToUse = [
  { title: 'Interstellar' } as Movie,
  { title: 'The Green Book' } as Movie,
  { title: 'Dark Knight' } as Movie