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

react-testing-library

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

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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.

This solution

The react-testing-library is a very light-weight 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.

Example

// __tests__/fetch.js
import React from 'react'
import {render, fireEvent, cleanup, waitForElement} from 'react-testing-library'
// this adds custom jest matchers from jest-dom
import 'jest-dom/extend-expect'

// the mock lives in a __mocks__ directory
// to know more about manual mocks, access: https://jestjs.io/docs/en/manual-mocks
import axiosMock from 'axios'
import Fetch from '../fetch' // see the tests for a full implementation

// automatically unmount and cleanup DOM after the test is finished.
afterEach(cleanup)

test('Fetch makes an API call and displays the greeting when load-greeting is clicked', async () => {
  // Arrange
  axiosMock.get.mockResolvedValueOnce({data: {greeting: 'hello there'}})
  const url = '/greeting'
  const {getByText, getByTestId, container, asFragment} = render(
    <Fetch url={url} />,
  )

  // Act
  fireEvent.click(getByText(/load greeting/i))

  // Let's wait until our mocked `get` request promise resolves and
  // the component calls setState and re-renders.
  // getByTestId throws an error if it cannot find an element with the given ID
  // and waitForElement will wait until the callback doesn't throw an error
  const greetingTextNode = await waitForElement(() =>
    getByTestId('greeting-text'),
  )

  // Assert
  expect(axiosMock.get).toHaveBeenCalledTimes(1)
  expect(axiosMock.get).toHaveBeenCalledWith(url)
  expect(getByTestId('greeting-text')).toHaveTextContent('hello there')
  expect(getByTestId('ok-button')).toHaveAttribute('disabled')
  // snapshots work great with regular DOM nodes!
  expect(container.firstChild).toMatchSnapshot()
  // you can also use get a `DocumentFragment`, which is useful if you want to compare nodes across render
  expect(asFragment()).toMatchSnapshot()
})

Installation

This module is distributed via npm which is bundled with node and should be installed as one of your project's devDependencies:

npm install --save-dev react-testing-library

This library has peerDependencies listings for react and react-dom.

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

Docs

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 examples directory. Some included are:

You can also find react-testing-library examples at react-testing-examples.com.

Other Solutions

In preparing this project, I tweeted about it and Sune Simonsen took up the challenge. We had different ideas of what to include in the library, so I decided to create this one instead.

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.

At the end of the day, what we want is for this library to be pretty light-weight, simple, and understandable.

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

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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

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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€” ⚠️
mohamedmagdy17593
mohamedmagdy17593

πŸ’»

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

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.

LICENSE

MIT