[ Jest Each ] https://itnext.io/reduce-unit-tests-boilerplate-with-jests-each-syntax-f5e48828437f #jest #development #tdd

jest-each-example.js

import React from 'react';
import { shallow } from 'enzyme';
import Button from './Button';

let props;

beforeEach(() => {
  props = {
    isPrimary: false,
    isDanger: false,
    isSuccess: false,
  };
});

describe('test Button component', () => {
  it.each`
    propName       | propValue | className       | result
    ${'isPrimary'} | ${true}   | ${'is-primary'} | ${true}
    ${'isDanger'}  | ${true}   | ${'is-danger'}  | ${true}
    ${'isSuccess'} | ${true}   | ${'is-success'} | ${true}
  `('should have class $className when prop $propName is equal to $propValue', ({propName, propValue, className, result}) => {
    props = { ...props, [propName]: propValue };
    const enzymeWrapper = shallow(<Button {...props} />);

    expect(enzymeWrapper.hasClass(className)).toEqual(result);
  });
  
  it.each`
  propName       | propValue | className       | result
  ${'isPrimary'} | ${false}  | ${'is-primary'} | ${false}
  ${'isDanger'}  | ${false}  | ${'is-danger'}  | ${false}
  ${'isSuccess'} | ${false}  | ${'is-success'} | ${false}
`('should have not class $className when prop $propName is equal to $propValue', ({propName, propValue, className, result}) => {
  props = { ...props, [propName]: propValue };
  const enzymeWrapper = shallow(<Button {...props} />);

  expect(enzymeWrapper.hasClass(className)).toEqual(result);
});
});

God