Cheat Sheet for Jest and Enzyme

jest-enzyme-cheat-sheet.js

import Enzyme, { mount } from 'enzyme';

// mount a component with props
const loginProps = { title: 'Login Form' }
const loginForm = mount(<LoginPage {...loginProps} />);

// access child component based on prop key value
const passwordField = loginForm.find('FormItem').filterWhere((item => {
  return item.prop('name') === 'password';
}));


// check a prop value
expect(loginform.prop('title')).toBe('Login Form');

// check a state value
expect(loginForm.state('password')).toEqual('123456');

// Check effect after submit a form
const flushPromises = () => new Promise(setImmediate);
loginForm.find('form').simulate('submit', event);
await flushPromises();
loginForm.update();
expect(loginForm.state('error')).toEqual('incorrect password');


// test with js-cookie
import Cookie from 'js-cookie';
it('sets token to cookie', async() => {
  // other codes ...
  loginForm.find('form').simulate('submit', event);

  await flushPromises();
  loginForm.update();

  expect(Cookie.get('token')).toEqual('token-mock');
});