I'm building a new project and I'm trying to use TDD as my default methodology and trying to apply it with integration test.
The thing is easy I want to retrieve all the users from my DB.
//controller.js
const UserService = require('../services/user');
module.exports = {
// corresponds to /users
getAllUsers: async (req, res, next) => {
const users = await UserService.fetchAllUsers();
res.send(users);
},
};
const models = require('../database/models/index'); // I tried also with destructuring
module.exports = {
fetchAllUsers: async () => models.user.findAll(),
};
and my actual test file looks like
const request = require('supertest');
const SequelizeMock = require('sequelize-mock');
const app = require('..');
const dbMock = new SequelizeMock();
const models = require('../src/database/models/index');
jest.mock('../src/database/models/index', () => ({
user: jest.fn(),
}));
models.user.mockImplementation(() => {
const UserMock = dbMock.define('user', {});
UserMock.$queueResult(UserMock.build({
username: 'username',
mail: 'myMail@myMail.com',
}));
return UserMock;
});
describe('Demo test', () => {
it('should respond to users route', (done) => {
request(app)
.get('/users')
.end((err, res) => {
expect(err).toBeNull();
expect(res.status).toBe(200);
expect(res.json).toBe('object');
done();
});
});
});
All of this is actually working but when I'm trying to mock the user I TypeError: models.user.findAll is not a function
I need to replace the model.user with the UserMock's value.
Is there anyway to do this? or I should just mock findAll like
jest.mock('../src/database/models/index', () => ({
user: () => ({ findAll: jest.fn() }),
}));
``
In this case, I was not mocking what I wanted to.
If you wish to mock the models all you need to do is use SpyOn
like
const { sequelize, Report, User } = require('../../database/models/index');
describe("my test", () => {
it("should just mock", () => {
jest.SpyOn(Report, "count").mockResolvedOnce(6);
})
})
In the case that you need to mock like your service
first create jest functions to allow the access from outside the scope of your mock and then mock it with "double class call"
const BaseService = require('../BaseService');
const mockFecthOne = jest.fn();
jest.mock('../BaseService',
() => jest.fn().mockImplementation(
() => ({
fetchOne: mockFetchOne,
}),
));
// inside your test just
BaseService().fetchOne.mockResolvedOnce({....})
and thats it hope it works.