Snapshot Tesz

snapshot.test.js

/* src/components/Counter/test/Counter.test.js */
import React from 'react'
import Counter from '../';
import { shallow } from 'enzyme';
import toJson from 'enzyme-to-json'

const callBackFunc = jest.fn();
const counterComponent = shallow(<Counter callBack = {callBackFunc} />);

describe('<counterComponent />', () => {
  (...)
  it('turns red on negative amounts', () => {
    counterComponent.setState({amount:-2});
    expect(toJson(counterComponent)).toMatchSnapshot();
    expect(counterComponent.find("[data-test='counterComponent']")
    .first().hasClass('counter--negative')).toBe(true);
  });
  
})