@testing-library/react

Simple and complete React DOM testing utilities that encourage good testing practices.


Keywords
testing, react, ui, dom, jsdom, unit, integration, functional, end-to-end, e2e, javascript, reactjs
License
MIT
Install
npm install @testing-library/react@16.0.1

Documentation

React Testing Library

goat

Simple and complete React DOM testing utilities that encourage good testing practices.


Read The Docs | Edit the docs



Build Status Code Coverage version downloads MIT License All Contributors PRs Welcome Code of Conduct Discord

Watch on GitHub Star on GitHub Tweet

Table of Contents

The problem

You want to write maintainable tests for your React components. As a part of this goal, you want your tests to avoid including implementation details of your components and rather focus on making your tests give you the confidence for which they are intended. As part of this, you want your testbase to be maintainable in the long run so refactors of your components (changes to implementation but not functionality) don't break your tests and slow you and your team down.

The solution

The React Testing Library is a very lightweight solution for testing React components. It provides light utility functions on top of react-dom and react-dom/test-utils, in a way that encourages better testing practices. Its primary guiding principle is:

The more your tests resemble the way your software is used, the more confidence they can give you.

Installation

This module is distributed via npm which is bundled with node and should be installed as one of your project's devDependencies.
Starting from RTL version 16, you'll also need to install @testing-library/dom:

npm install --save-dev @testing-library/react @testing-library/dom

or

for installation via yarn

yarn add --dev @testing-library/react @testing-library/dom

This library has peerDependencies listings for react, react-dom and starting from RTL version 16 also @testing-library/dom.

React Testing Library versions 13+ require React v18. If your project uses an older version of React, be sure to install version 12:

npm install --save-dev @testing-library/react@12


yarn add --dev @testing-library/react@12

You may also be interested in installing @testing-library/jest-dom so you can use the custom jest matchers.

Docs

Suppressing unnecessary warnings on React DOM 16.8

There is a known compatibility issue with React DOM 16.8 where you will see the following warning:

Warning: An update to ComponentName inside a test was not wrapped in act(...).

If you cannot upgrade to React DOM 16.9, you may suppress the warnings by adding the following snippet to your test configuration (learn more):

// this is just a little hack to silence a warning that we'll get until we
// upgrade to 16.9. See also: https://github.com/facebook/react/pull/14853
const originalError = console.error
beforeAll(() => {
  console.error = (...args) => {
    if (/Warning.*not wrapped in act/.test(args[0])) {
      return
    }
    originalError.call(console, ...args)
  }
})

afterAll(() => {
  console.error = originalError
})

Examples

Basic Example

// hidden-message.js
import * as React from 'react'

// NOTE: React Testing Library works well with React Hooks and classes.
// Your tests will be the same regardless of how you write your components.
function HiddenMessage({children}) {
  const [showMessage, setShowMessage] = React.useState(false)
  return (
    <div>
      <label htmlFor="toggle">Show Message</label>
      <input
        id="toggle"
        type="checkbox"
        onChange={e => setShowMessage(e.target.checked)}
        checked={showMessage}
      />
      {showMessage ? children : null}
    </div>
  )
}

export default HiddenMessage
// __tests__/hidden-message.js
// these imports are something you'd normally configure Jest to import for you
// automatically. Learn more in the setup docs: https://testing-library.com/docs/react-testing-library/setup#cleanup
import '@testing-library/jest-dom'
// NOTE: jest-dom adds handy assertions to Jest and is recommended, but not required

import * as React from 'react'
import {render, fireEvent, screen} from '@testing-library/react'
import HiddenMessage from '../hidden-message'

test('shows the children when the checkbox is checked', () => {
  const testMessage = 'Test Message'
  render(<HiddenMessage>{testMessage}</HiddenMessage>)

  // query* functions will return the element or null if it cannot be found
  // get* functions will return the element or throw an error if it cannot be found
  expect(screen.queryByText(testMessage)).toBeNull()

  // the queries can accept a regex to make your selectors more resilient to content tweaks and changes.
  fireEvent.click(screen.getByLabelText(/show/i))

  // .toBeInTheDocument() is an assertion that comes from jest-dom
  // otherwise you could use .toBeDefined()
  expect(screen.getByText(testMessage)).toBeInTheDocument()
})

Complex Example

// login.js
import * as React from 'react'

function Login() {
  const [state, setState] = React.useReducer((s, a) => ({...s, ...a}), {
    resolved: false,
    loading: false,
    error: null,
  })

  function handleSubmit(event) {
    event.preventDefault()
    const {usernameInput, passwordInput} = event.target.elements

    setState({loading: true, resolved: false, error: null})

    window
      .fetch('/api/login', {
        method: 'POST',
        headers: {'Content-Type': 'application/json'},
        body: JSON.stringify({
          username: usernameInput.value,
          password: passwordInput.value,
        }),
      })
      .then(r => r.json().then(data => (r.ok ? data : Promise.reject(data))))
      .then(
        user => {
          setState({loading: false, resolved: true, error: null})
          window.localStorage.setItem('token', user.token)
        },
        error => {
          setState({loading: false, resolved: false, error: error.message})
        },
      )
  }

  return (
    <div>
      <form onSubmit={handleSubmit}>
        <div>
          <label htmlFor="usernameInput">Username</label>
          <input id="usernameInput" />
        </div>
        <div>
          <label htmlFor="passwordInput">Password</label>
          <input id="passwordInput" type="password" />
        </div>
        <button type="submit">Submit{state.loading ? '...' : null}</button>
      </form>
      {state.error ? <div role="alert">{state.error}</div> : null}
      {state.resolved ? (
        <div role="alert">Congrats! You're signed in!</div>
      ) : null}
    </div>
  )
}

export default Login
// __tests__/login.js
// again, these first two imports are something you'd normally handle in
// your testing framework configuration rather than importing them in every file.
import '@testing-library/jest-dom'
import * as React from 'react'
// import API mocking utilities from Mock Service Worker.
import {rest} from 'msw'
import {setupServer} from 'msw/node'
// import testing utilities
import {render, fireEvent, screen} from '@testing-library/react'
import Login from '../login'

const fakeUserResponse = {token: 'fake_user_token'}
const server = setupServer(
  rest.post('/api/login', (req, res, ctx) => {
    return res(ctx.json(fakeUserResponse))
  }),
)

beforeAll(() => server.listen())
afterEach(() => {
  server.resetHandlers()
  window.localStorage.removeItem('token')
})
afterAll(() => server.close())

test('allows the user to login successfully', async () => {
  render(<Login />)

  // fill out the form
  fireEvent.change(screen.getByLabelText(/username/i), {
    target: {value: 'chuck'},
  })
  fireEvent.change(screen.getByLabelText(/password/i), {
    target: {value: 'norris'},
  })

  fireEvent.click(screen.getByText(/submit/i))

  // just like a manual tester, we'll instruct our test to wait for the alert
  // to show up before continuing with our assertions.
  const alert = await screen.findByRole('alert')

  // .toHaveTextContent() comes from jest-dom's assertions
  // otherwise you could use expect(alert.textContent).toMatch(/congrats/i)
  // but jest-dom will give you better error messages which is why it's recommended
  expect(alert).toHaveTextContent(/congrats/i)
  expect(window.localStorage.getItem('token')).toEqual(fakeUserResponse.token)
})

test('handles server exceptions', async () => {
  // mock the server error response for this test suite only.
  server.use(
    rest.post('/api/login', (req, res, ctx) => {
      return res(ctx.status(500), ctx.json({message: 'Internal server error'}))
    }),
  )

  render(<Login />)

  // fill out the form
  fireEvent.change(screen.getByLabelText(/username/i), {
    target: {value: 'chuck'},
  })
  fireEvent.change(screen.getByLabelText(/password/i), {
    target: {value: 'norris'},
  })

  fireEvent.click(screen.getByText(/submit/i))

  // wait for the error message
  const alert = await screen.findByRole('alert')

  expect(alert).toHaveTextContent(/internal server error/i)
  expect(window.localStorage.getItem('token')).toBeNull()
})

We recommend using Mock Service Worker library to declaratively mock API communication in your tests instead of stubbing window.fetch, or relying on third-party adapters.

More Examples

We're in the process of moving examples to the docs site

You'll find runnable examples of testing with different libraries in the react-testing-library-examples codesandbox. Some included are:

Hooks

If you are interested in testing a custom hook, check out React Hooks Testing Library.

NOTE: it is not recommended to test single-use custom hooks in isolation from the components where it's being used. It's better to test the component that's using the hook rather than the hook itself. The React Hooks Testing Library is intended to be used for reusable hooks/libraries.

Guiding Principles

The more your tests resemble the way your software is used, the more confidence they can give you.

We try to only expose methods and utilities that encourage you to write tests that closely resemble how your React components are used.

Utilities are included in this project based on the following guiding principles:

  1. If it relates to rendering components, it deals with DOM nodes rather than component instances, nor should it encourage dealing with component instances.
  2. It should be generally useful for testing individual React components or full React applications. While this library is focused on react-dom, utilities could be included even if they don't directly relate to react-dom.
  3. Utility implementations and APIs should be simple and flexible.

Most importantly, we want React Testing Library to be pretty light-weight, simple, and easy to understand.

Docs

Read The Docs | Edit the docs

Issues

Looking to contribute? Look for the Good First Issue label.

πŸ› Bugs

Please file an issue for bugs, missing documentation, or unexpected behavior.

See Bugs

πŸ’‘ Feature Requests

Please file an issue to suggest new features. Vote on feature requests by adding a πŸ‘. This helps maintainers prioritize what to work on.

See Feature Requests

❓ Questions

For questions related to using the library, please visit a support community instead of filing an issue on GitHub.

Contributors

Thanks goes to these people (emoji key):

Kent C. Dodds
Kent C. Dodds

πŸ’» πŸ“– πŸš‡ ⚠️
Ryan Castner
Ryan Castner

πŸ“–
Daniel Sandiego
Daniel Sandiego

πŸ’»
PaweΕ‚ MikoΕ‚ajczyk
PaweΕ‚ MikoΕ‚ajczyk

πŸ’»
Alejandro ÑÑñez Ortiz
Alejandro ÑÑñez Ortiz

πŸ“–
Matt Parrish
Matt Parrish

πŸ› πŸ’» πŸ“– ⚠️
Justin Hall
Justin Hall

πŸ“¦
Anto Aravinth
Anto Aravinth

πŸ’» ⚠️ πŸ“–
Jonah Moses
Jonah Moses

πŸ“–
Łukasz Gandecki
Łukasz Gandecki

πŸ’» ⚠️ πŸ“–
Ivan Babak
Ivan Babak

πŸ› πŸ€”
Jesse Day
Jesse Day

πŸ’»
Ernesto GarcΓ­a
Ernesto GarcΓ­a

πŸ’¬ πŸ’» πŸ“–
Josef Maxx Blake
Josef Maxx Blake

πŸ’» πŸ“– ⚠️
Michal Baranowski
Michal Baranowski

πŸ“ βœ…
Arthur Puthin
Arthur Puthin

πŸ“–
Thomas Chia
Thomas Chia

πŸ’» πŸ“–
Thiago Galvani
Thiago Galvani

πŸ“–
Christian
Christian

⚠️
Alex Krolick
Alex Krolick

πŸ’¬ πŸ“– πŸ’‘ πŸ€”
Johann Hubert Sonntagbauer
Johann Hubert Sonntagbauer

πŸ’» πŸ“– ⚠️
Maddi Joyce
Maddi Joyce

πŸ’»
Ryan Vice
Ryan Vice

πŸ“–
Ian Wilson
Ian Wilson

πŸ“ βœ…
Daniel
Daniel

πŸ› πŸ’»
Giorgio Polvara
Giorgio Polvara

πŸ› πŸ€”
John Gozde
John Gozde

πŸ’»
Sam Horton
Sam Horton

πŸ“– πŸ’‘ πŸ€”
Richard Kotze (mobile)
Richard Kotze (mobile)

πŸ“–
Brahian E. Soto Mercedes
Brahian E. Soto Mercedes

πŸ“–
Benoit de La Forest
Benoit de La Forest

πŸ“–
Salah
Salah

πŸ’» ⚠️
Adam Gordon
Adam Gordon

πŸ› πŸ’»
Matija Marohnić
Matija Marohnić

πŸ“–
Justice Mba
Justice Mba

πŸ“–
Mark Pollmann
Mark Pollmann

πŸ“–
Ehtesham Kafeel
Ehtesham Kafeel

πŸ’» πŸ“–
Julio PavΓ³n
Julio PavΓ³n

πŸ’»
Duncan L
Duncan L

πŸ“– πŸ’‘
Tiago Almeida
Tiago Almeida

πŸ“–
Robert Smith
Robert Smith

πŸ›
Zach Green
Zach Green

πŸ“–
dadamssg
dadamssg

πŸ“–
Yazan Aabed
Yazan Aabed

πŸ“
Tim
Tim

πŸ› πŸ’» πŸ“– ⚠️
Divyanshu Maithani
Divyanshu Maithani

βœ… πŸ“Ή
Deepak Grover
Deepak Grover

βœ… πŸ“Ή
Eyal Cohen
Eyal Cohen

πŸ“–
Peter Makowski
Peter Makowski

πŸ“–
Michiel Nuyts
Michiel Nuyts

πŸ“–
Joe Ng'ethe
Joe Ng'ethe

πŸ’» πŸ“–
Kate
Kate

πŸ“–
Sean
Sean

πŸ“–
James Long
James Long

πŸ€” πŸ“¦
Herb Hagely
Herb Hagely

πŸ’‘
Alex Wendte
Alex Wendte

πŸ’‘
Monica Powell
Monica Powell

πŸ“–
Vitaly Sivkov
Vitaly Sivkov

πŸ’»
Weyert de Boer
Weyert de Boer

πŸ€” πŸ‘€ 🎨
EstebanMarin
EstebanMarin

πŸ“–
Victor Martins
Victor Martins

πŸ“–
Royston Shufflebotham
Royston Shufflebotham

πŸ› πŸ“– πŸ’‘
chrbala
chrbala

πŸ’»
Donavon West
Donavon West

πŸ’» πŸ“– πŸ€” ⚠️
Richard Maisano
Richard Maisano

πŸ’»
Marco Biedermann
Marco Biedermann

πŸ’» 🚧 ⚠️
Alex Zherdev
Alex Zherdev

πŸ› πŸ’»
AndrΓ© Matulionis dos Santos
AndrΓ© Matulionis dos Santos

πŸ’» πŸ’‘ ⚠️
Daniel K.
Daniel K.

πŸ› πŸ’» πŸ€” ⚠️ πŸ‘€
mohamedmagdy17593
mohamedmagdy17593

πŸ’»
Loren ☺️
Loren ☺️

πŸ“–
MarkFalconbridge
MarkFalconbridge

πŸ› πŸ’»
Vinicius
Vinicius

πŸ“– πŸ’‘
Peter Schyma
Peter Schyma

πŸ’»
Ian Schmitz
Ian Schmitz

πŸ“–
Joel Marcotte
Joel Marcotte

πŸ› ⚠️ πŸ’»
Alejandro Dustet
Alejandro Dustet

πŸ›
Brandon Carroll
Brandon Carroll

πŸ“–
Lucas Machado
Lucas Machado

πŸ“–
Pascal Duez
Pascal Duez

πŸ“¦
Minh Nguyen
Minh Nguyen

πŸ’»
LiaoJimmy
LiaoJimmy

πŸ“–
Sunil Pai
Sunil Pai

πŸ’» ⚠️
Dan Abramov
Dan Abramov

πŸ‘€
Christian Murphy
Christian Murphy

πŸš‡
Ivakhnenko Dmitry
Ivakhnenko Dmitry

πŸ’»
James George
James George

πŸ“–
JoΓ£o Fernandes
JoΓ£o Fernandes

πŸ“–
Alejandro Perea
Alejandro Perea

πŸ‘€
Nick McCurdy
Nick McCurdy

πŸ‘€ πŸ’¬ πŸš‡
Sebastian Silbermann
Sebastian Silbermann

πŸ‘€
AdriΓ  Fontcuberta
AdriΓ  Fontcuberta

πŸ‘€ πŸ“–
John Reilly
John Reilly

πŸ‘€
MichaΓ«l De Boey
MichaΓ«l De Boey

πŸ‘€ πŸ’»
Tim Yates
Tim Yates

πŸ‘€
Brian Donovan
Brian Donovan

πŸ’»
Noam Gabriel Jacobson
Noam Gabriel Jacobson

πŸ“–
Ronald van der Kooij
Ronald van der Kooij

⚠️ πŸ’»
Aayush Rajvanshi
Aayush Rajvanshi

πŸ“–
Ely Alamillo
Ely Alamillo

πŸ’» ⚠️
Daniel Afonso
Daniel Afonso

πŸ’» ⚠️
Laurens Bosscher
Laurens Bosscher

πŸ’»
Sakito Mukai
Sakito Mukai

πŸ“–
TΓΌrker Teke
TΓΌrker Teke

πŸ“–
Zach Brogan
Zach Brogan

πŸ’» ⚠️
Ryota Murakami
Ryota Murakami

πŸ“–
Michael Hottman
Michael Hottman

πŸ€”
Steven Fitzpatrick
Steven Fitzpatrick

πŸ›
Juan Je GarcΓ­a
Juan Je GarcΓ­a

πŸ“–
Championrunner
Championrunner

πŸ“–
Sam Tsai
Sam Tsai

πŸ’» ⚠️ πŸ“–
Christian Rackerseder
Christian Rackerseder

πŸ’»
Andrei Picus
Andrei Picus

πŸ› πŸ‘€
Artem Zakharchenko
Artem Zakharchenko

πŸ“–
Michael
Michael

πŸ“–
Braden Lee
Braden Lee

πŸ“–
Kamran Ayub
Kamran Ayub

πŸ’» ⚠️
Matan Borenkraout
Matan Borenkraout

πŸ’»
Ryan Bigg
Ryan Bigg

🚧
Anton Halim
Anton Halim

πŸ“–
Artem Malko
Artem Malko

πŸ’»
Gerrit Alex
Gerrit Alex

πŸ’»
Karthick Raja
Karthick Raja

πŸ’»
Abdelrahman Ashraf
Abdelrahman Ashraf

πŸ’»
Lidor Avitan
Lidor Avitan

πŸ“–
Jordan Harband
Jordan Harband

πŸ‘€ πŸ€”
Marco Moretti
Marco Moretti

πŸ’»
sanchit121
sanchit121

πŸ› πŸ’»
Solufa
Solufa

πŸ› πŸ’»
Ari PerkkiΓΆ
Ari PerkkiΓΆ

⚠️
Johannes Ewald
Johannes Ewald

πŸ’»
Angus J. Pope
Angus J. Pope

πŸ“–
Dominik Lesch
Dominik Lesch

πŸ“–
Marcos GΓ³mez
Marcos GΓ³mez

πŸ“–
Akash Shyam
Akash Shyam

πŸ›
Fabian Meumertzheim
Fabian Meumertzheim

πŸ’» πŸ›
Sebastian Malton
Sebastian Malton

πŸ› πŸ’»
Martin BΓΆttcher
Martin BΓΆttcher

πŸ’»
Dominik Dorfmeister
Dominik Dorfmeister

πŸ’»
Stephen Sauceda
Stephen Sauceda

πŸ“–
Colin Diesh
Colin Diesh

πŸ“–
Yusuke Iinuma
Yusuke Iinuma

πŸ’»
Jeff Way
Jeff Way

πŸ’»

This project follows the all-contributors specification. Contributions of any kind welcome!

LICENSE

MIT