How to compare mongoose model objects in jest while excluding _id

The schema model object in Mongoose provides an _id that is of type ObjectId. If you are not interested in comparing value of this attribute when you compare it compare objects in jest, you can exclude it by calling the toObject method of the mongoose model and set the _id object to nothing via the spread operator, something similar to the following:

expect({...resultBookmark.toObject(), _id: {}}).toEqual({...expectedBookmark.toObject(), _id: {}})

The complete testing method with the setup is shown in the snippet bellow,
where expected bookmark model should match the mapped bookmark from the given request:

const showdown = require('showdown');
const Bookmark = require('../../model/bookmark');
const bookmarkRequestMapper = require('./bookmark-request.mapper');

jest.mock('showdown', () => {
  const makeHtml = jest.fn(() => '<p>This is a test bookmark</p>');
  return {
    Converter: jest.fn().mockImplementation(() => ({makeHtml})),
  };
});

describe('toBookmark', () => {
  const req = {
    body: {
      _id: '123',
      name: 'Test Bookmark',
      location: 'https://example.com',
      language: 'en',
      description: 'This is a test bookmark',
      tags: ['test'],
      public: true,
    },
    params: {
      userId: '456',
    },
  };

  beforeEach(() => {
    showdown.Converter.mockClear();
    showdown.Converter().makeHtml.mockClear();
    req.body.descriptionHtml = undefined;
    req.body.youtubeVideoId = undefined;
    req.body.stackoverflowQuestionId = undefined;
  });

  it('should use descriptionHtml if it is provided', () => {
    req.body.descriptionHtml = '<p>This is a test bookmark</p>';

    const expectedBookmark = new Bookmark({
      _id: '123',
      name: 'Test Bookmark',
      location: 'https://example.com',
      language: 'en',
      description: 'This is a test bookmark',
      descriptionHtml: '<p>This is a test bookmark</p>',
      tags: ['test'],
      public: true,
      userId: '456',
      likeCount: 0,
      youtubeVideoId: null,
      stackoverflowQuestionId: null,
    });

    const resultBookmark = bookmarkRequestMapper.toBookmark(req);

    expect({...resultBookmark.toObject(), _id: {}}).toEqual({...expectedBookmark.toObject(), _id: {}})
    expect(showdown.Converter().makeHtml).not.toHaveBeenCalled();
  });
});

Project: codever - File: bookmark-request.mapper.test.js

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