newsletter.service.spec.ts

import { HttpModule } from '@nestjs/axios';
import { HttpStatus } from '@nestjs/common';
import { getModelToken } from '@nestjs/mongoose';
import { Test, TestingModule } from '@nestjs/testing';
import { INewsletterSubscription } from './interface/newsletter-subscription.interface';
import { NewsletterSubscription } from './newsletter-subscription.schema';
import { NewsletterService } from './newsletter.service';
// eslint-disable-next-line @typescript-eslint/no-var-requires
const mailchimp = require('@mailchimp/mailchimp_marketing');
jest.mock('@mailchimp/mailchimp_marketing');
describe('NewsletterService', () => {
  const OLD_ENV = process.env;
  let newsletterService: NewsletterService;

  const mockNewsletterModel = {
    create: jest.fn(),
    deleteOne: jest.fn(),
    countDocuments: jest.fn(),
    findOne: jest.fn(),
    exec: jest.fn(),
    find: jest.fn(),
  };

  beforeEach(async () => {
    jest.resetModules(); // Most important - it clears the cache
    const module: TestingModule = await Test.createTestingModule({
      imports: [HttpModule],
      providers: [
        NewsletterService,
        {
          provide: getModelToken(NewsletterSubscription.name),
          useValue: mockNewsletterModel,
        },
      ],
    }).compile();

    newsletterService = module.get<NewsletterService>(NewsletterService);

    process.env = { ...OLD_ENV }; // Make a copy
    process.env.MC_LIST_ID = 'abcde';
    process.env.MC_API_KEY = 'k3y';
    process.env.MC_SERVER = 's3rv3r';
  });

  afterAll(() => {
    process.env = OLD_ENV; // Restore old environment
  });

  it('should be defined', () => {
    expect(newsletterService).toBeDefined();
  });

  describe('newsletterSubscribe', () => {
    it('it should add subscription for email test2@test.com even if it exists', async () => {
      const _doc = { _id: 'a1aaaaa1a1', email: 'test2@test.com' } as INewsletterSubscription;
      mailchimp.lists.setListMember.mockResolvedValueOnce({ email_address: 'test2@test.com' });
      jest
        .spyOn(newsletterService, 'findOne')
        .mockImplementationOnce(async (): Promise<INewsletterSubscription | undefined> => _doc);
      mockNewsletterModel.create.mockResolvedValueOnce(_doc);

      const subscription = await newsletterService.newsletterSubscribe('test2@test.com');
      expect(subscription).toEqual(_doc);
    });
    it('it should add a subscription for email test2@test.com', async () => {
      const result = { email: 'test2@test.com' } as INewsletterSubscription;
      const _doc = { _id: 'a1aaaaa1a1', email: 'test2@test.com' };
      mailchimp.lists.setListMember.mockResolvedValueOnce({ email_address: 'test2@test.com' });
      jest
        .spyOn(newsletterService, 'findOne')