simulate state change enzyme code example

Example: react enzyme simulate change

// app.js
import React from 'react'

const App = (props) => {
  return (
    <>
      <input type='text' name='username' value={props.username} onChange={props.onChange} />
      <input type='email' name='email' value={props.email} onChange={props.onChange} />
    </>
  )
}

export default App

// App.test
import React from 'react'
import { shallow } from 'enzyme'
import App from './App'

it('change value', () => {
  const state = { username: 'joe', email: '[email protected]' }

  const props = {
    username: state.username,
    email: state.email,
    onChange: (e) => {
      state[e.target.name] = e.target.value
    }
  }

  const wrapper = shallow(<App {...props} />)

  expect(wrapper.find('input').at(0).prop('value')).toEqual('joe')
  expect(wrapper.find('input').at(1).prop('value')).toEqual('[email protected]')

  wrapper
    .find('input')
    .at(0)
    .simulate('change', { target: { name: 'username', value: 'john doe' } })
  expect(state.username).toEqual('john doe')

  wrapper
    .find('input')
    .at(1)
    .simulate('change', { target: { name: 'email', value: '[email protected]' } })
  expect(state.email).toEqual('[email protected]')

  console.log(wrapper.debug())
})