Setup
React Testing Library
does not require any configuration to be used. However,
there are some things you can do when configuring your testing framework to
reduce some boilerplate. In these docs we'll demonstrate configuring Jest, but
you should be able to do similar things with
any testing framework (React Testing Library does not
require that you use Jest).
Global Config
Adding options to your global test config can simplify the setup and teardown of tests in individual files.
Custom Render
It's often useful to define a custom render method that includes things like
global context providers, data stores, etc. To make this available globally, one
approach is to define a utility file that re-exports everything from
React Testing Library
. You can replace React Testing Library with this file in
all your imports. See below for a way to
make your test util file accessible without using relative paths.
The example below sets up data providers using the wrapper
option to render
.
- JavaScript
- TypeScript
- import { render, fireEvent } from '@testing-library/react';
+ import { render, fireEvent } from '../test-utils';
import React from 'react'
import {render} from '@testing-library/react'
import {ThemeProvider} from 'my-ui-lib'
import {TranslationProvider} from 'my-i18n-lib'
import defaultStrings from 'i18n/en-x-default'
const AllTheProviders = ({children}) => {
return (
<ThemeProvider theme="light">
<TranslationProvider messages={defaultStrings}>
{children}
</TranslationProvider>
</ThemeProvider>
)
}
const customRender = (ui, options) =>
render(ui, {wrapper: AllTheProviders, ...options})
// re-export everything
export * from '@testing-library/react'
// override render method
export {customRender as render}
- import { render, fireEvent } from '@testing-library/react';
+ import { render, fireEvent } from '../test-utils';
import React, {ReactElement} from 'react'
import {render, RenderOptions} from '@testing-library/react'
import {ThemeProvider} from 'my-ui-lib'
import {TranslationProvider} from 'my-i18n-lib'
import defaultStrings from 'i18n/en-x-default'
const AllTheProviders = ({children}: {children: React.ReactNode}) => {
return (
<ThemeProvider theme="light">
<TranslationProvider messages={defaultStrings}>
{children}
</TranslationProvider>
</ThemeProvider>
)
}
const customRender = (
ui: ReactElement,
options?: Omit<RenderOptions, 'wrapper'>,
) => render(ui, {wrapper: AllTheProviders, ...options})
export * from '@testing-library/react'
export {customRender as render}
Note
Babel versions lower than 7 throw an error when trying to override the named export in the example above. See #169 and the workaround below.
Workaround for Babel 6
You can use CommonJS modules instead of ES modules, which should work in Node:
const rtl = require('@testing-library/react')
const customRender = (ui, options) =>
rtl.render(ui, {
myDefaultOption: 'something',
...options,
})
module.exports = {
...rtl,
render: customRender,
}
Add custom queries
Note
Generally you should not need to create custom queries for react-testing-library. Where you do use it, you should consider whether your new queries encourage you to test in a user-centric way, without testing implementation details.
You can define your own custom queries as described in the
Custom Queries documentation, or
via the
buildQueries
helper. Then you can use them in any render call using the queries
option. To
make the custom queries available globally, you can add them to your custom
render method as shown below.
In the example below, a new set of query variants are created for getting
elements by data-cy
, a "test ID" convention mentioned in the
Cypress.io
documentation.
- JavaScript
- TypeScript
import {queryHelpers, buildQueries} from '@testing-library/react'
// The queryAllByAttribute is a shortcut for attribute-based matchers
// You can also use document.querySelector or a combination of existing
// testing library utilities to find matching nodes for your query
const queryAllByDataCy = (...args) =>
queryHelpers.queryAllByAttribute('data-cy', ...args)
const getMultipleError = (c, dataCyValue) =>
`Found multiple elements with the data-cy attribute of: ${dataCyValue}`
const getMissingError = (c, dataCyValue) =>
`Unable to find an element with the data-cy attribute of: ${dataCyValue}`
const [
queryByDataCy,
getAllByDataCy,
getByDataCy,
findAllByDataCy,
findByDataCy,
] = buildQueries(queryAllByDataCy, getMultipleError, getMissingError)
export {
queryByDataCy,
queryAllByDataCy,
getByDataCy,
getAllByDataCy,
findAllByDataCy,
findByDataCy,
}
import {
queryHelpers,
buildQueries,
Matcher,
MatcherOptions,
} from '@testing-library/react'
// The queryAllByAttribute is a shortcut for attribute-based matchers
// You can also use document.querySelector or a combination of existing
// testing library utilities to find matching nodes for your query
const queryAllByDataCy = (
container: HTMLElement,
id: Matcher,
options?: MatcherOptions | undefined,
) => queryHelpers.queryAllByAttribute('data-cy', container, id, options)
const getMultipleError = (c, dataCyValue) =>
`Found multiple elements with the data-cy attribute of: ${dataCyValue}`
const getMissingError = (c, dataCyValue) =>
`Unable to find an element with the data-cy attribute of: ${dataCyValue}`
const [
queryByDataCy,
getAllByDataCy,
getByDataCy,
findAllByDataCy,
findByDataCy,
] = buildQueries(queryAllByDataCy, getMultipleError, getMissingError)
export {
queryByDataCy,
queryAllByDataCy,
getByDataCy,
getAllByDataCy,
findAllByDataCy,
findByDataCy,
}
You can then override and append the new queries via the render function by
passing a queries
option.
If you want to add custom queries globally, you can do this by defining your
customized render
, screen
and within
methods:
- JavaScript
- TypeScript
import {render, queries, within} from '@testing-library/react'
import * as customQueries from './custom-queries'
const allQueries = {
...queries,
...customQueries,
}
const customScreen = within(document.body, allQueries)
const customWithin = element => within(element, allQueries)
const customRender = (ui, options) =>
render(ui, {queries: allQueries, ...options})
// re-export everything
export * from '@testing-library/react'
// override render method
export {customScreen as screen, customWithin as within, customRender as render}
import {render, queries, within, RenderOptions} from '@testing-library/react'
import * as customQueries from './custom-queries'
import {ReactElement} from 'react'
const allQueries = {
...queries,
...customQueries,
}
const customScreen = within(document.body, allQueries)
const customWithin = (element: ReactElement) => within(element, allQueries)
const customRender = (
ui: ReactElement,
options?: Omit<RenderOptions, 'queries'>,
) => render(ui, {queries: allQueries, ...options})
export * from '@testing-library/react'
export {customScreen as screen, customWithin as within, customRender as render}
You can then use your custom queries as you would any other query:
const {getByDataCy} = render(<Component />)
expect(getByDataCy('my-component')).toHaveTextContent('Hello')
Configuring Jest with Test Utils
To make your custom test file accessible in your Jest test files without using
relative imports (../../test-utils
), add the folder containing the file to the
Jest moduleDirectories
option.
This will make all the .js
files in the test-utils directory importable
without ../
.
- import { render, fireEvent } from '../test-utils';
+ import { render, fireEvent } from 'test-utils';
module.exports = {
moduleDirectories: [
'node_modules',
+ // add the directory with the test-utils.js file, for example:
+ 'utils', // a utility folder
+ __dirname, // the root directory
],
// ... other options ...
}
If you're using TypeScript, merge this into your tsconfig.json
. If you're
using Create React App without TypeScript, save this to jsconfig.json
instead.
{
"compilerOptions": {
"baseUrl": "src",
"paths": {
"test-utils": ["./utils/test-utils"]
}
}
}
Jest 28
If you're using Jest 28 or later, jest-environment-jsdom package now must be installed separately.
- npm
- Yarn
npm install --save-dev jest-environment-jsdom
yarn add --dev jest-environment-jsdom
jsdom
is also no longer the default environment. You can enable jsdom
globally by editing jest.config.js
:
module.exports = {
+ testEnvironment: 'jsdom',
// ... other options ...
}
Or if you only need jsdom
in some of your tests, you can enable it as and when
needed using
docblocks:
/**
* @jest-environment jsdom
*/
Jest 27
If you're using a recent version of Jest (27), jsdom
is no longer the default
environment. You can enable jsdom
globally by editing jest.config.js
:
module.exports = {
+ testEnvironment: 'jest-environment-jsdom',
// ... other options ...
}
Or if you only need jsdom
in some of your tests, you can enable it as and when
needed using
docblocks:
/**
* @jest-environment jsdom
*/
Jest 24 (or lower) and defaults
If you're using the Jest testing framework version 24 or lower with the default
configuration, it's recommended to use jest-environment-jsdom-fifteen
package
as Jest uses a version of the jsdom environment that misses some features and
fixes, required by React Testing Library.
First, install jest-environment-jsdom-fifteen
.
- npm
- Yarn
npm install --save-dev jest-environment-jsdom-fifteen
yarn add --dev jest-environment-jsdom-fifteen
Then specify jest-environment-jsdom-fifteen
as the testEnvironment
:
module.exports = {
+ testEnvironment: 'jest-environment-jsdom-fifteen',
// ... other options ...
}
Using without Jest
If you're running your tests in the browser bundled with webpack (or similar)
then React Testing Library
should work out of the box for you. However, most
people using React Testing Library are using it with the Jest testing framework
with the testEnvironment
set to jest-environment-jsdom
(which is the default
configuration with Jest 26 and earlier).
jsdom
is a pure JavaScript implementation of the DOM and browser APIs that
runs in Node. If you're not using Jest and you would like to run your tests in
Node, then you must install jsdom yourself. There's also a package called
global-jsdom
which can be used to setup the global environment to simulate the
browser APIs.
First, install jsdom
and global-jsdom
.
- npm
- Yarn
npm install --save-dev jsdom global-jsdom
yarn add --dev jsdom global-jsdom
With mocha, the test command would look something like this:
mocha --require global-jsdom/register
Skipping Auto Cleanup
Cleanup
is called after each test automatically by default
if the testing framework you're using supports the afterEach
global (like
mocha, Jest, and Jasmine). However, you may choose to skip the auto cleanup by
setting the RTL_SKIP_AUTO_CLEANUP
env variable to 'true'. You can do this with
cross-env
like so:
cross-env RTL_SKIP_AUTO_CLEANUP=true jest
To make this even easier, you can also simply import
@testing-library/react/dont-cleanup-after-each
which will do the same thing.
Just make sure you do this before importing @testing-library/react
. You could
do this with Jest's setupFiles
configuration:
{
// ... other jest config
setupFiles: ['@testing-library/react/dont-cleanup-after-each']
}
Or with mocha's -r
flag:
mocha --require @testing-library/react/dont-cleanup-after-each
Alternatively, you could import @testing-library/react/pure
in all your tests
that you don't want the cleanup
to run and the afterEach
won't be setup
automatically.
Auto Cleanup in Mocha's watch mode
When using Mocha in watch mode, the globally registered cleanup is run only the first time after each test. Therefore, subsequent runs will most likely fail with a TestingLibraryElementError: Found multiple elements error.
To enable automatic cleanup in Mocha's watch mode, add a cleanup
root hook. Create a
mocha-watch-cleanup-after-each.js
file with the following contents:
const {cleanup} = require('@testing-library/react')
exports.mochaHooks = {
afterEach() {
cleanup()
},
}
And register it using mocha's -r
flag:
mocha --require ./mocha-watch-cleanup-after-each.js