eslint-plugin-testing-library

What is eslint-plugin-testing-library?

The eslint-plugin-testing-library package is an ESLint plugin that provides linting rules for writing tests with the Testing Library, which is a set of utilities for testing UI components in a user-centric way. This plugin helps enforce best practices and eliminate common mistakes when writing tests with Testing Library.

What are eslint-plugin-testing-library's main functionalities?

Enforce consistent usage of Testing Library queries

This rule enforces the use of the `screen` object for querying DOM elements, which provides better consistency and avoids destructuring render result.

/* eslint testing-library/prefer-screen-queries: 'error' */
// Bad
const { getByText } = render(<App />);
getByText('Hello World');

// Good
const screen = render(<App />);
screen.getByText('Hello World');

Avoid using container methods

This rule prevents direct DOM manipulation by avoiding the use of the `container` method, encouraging the use of queries provided by Testing Library instead.

/* eslint testing-library/no-container: 'error' */
// Bad
const { container } = render(<App />);
container.querySelector('.my-class');

// Good
const { getByClassName } = render(<App />);
getByClassName('my-class');

Ensure async queries are awaited

This rule ensures that asynchronous queries like `findBy*` are properly awaited or returned in tests, which is necessary for correct test execution.

/* eslint testing-library/await-async-query: 'error' */
// Bad
getByText('Loading...');

// Good
await findByText('Loaded');

Prevent the use of debug

This rule warns or errors when the `debug` function is used, as it's intended for debugging purposes and should not be left in the final test code.

/* eslint testing-library/no-debug: 'warn' */
// Bad
const { debug } = render(<App />);
debug();

// Good
// No debug usage

Other packages similar to eslint-plugin-testing-library

eslint-plugin-jest-dom

This plugin provides ESLint rules for Jest DOM, which is a companion library for Testing Library that provides custom DOM element matchers for Jest. It enforces best practices and consistency for using Jest DOM matchers.

eslint-plugin-jest

This plugin is focused on linting Jest test code. It includes a variety of rules that help enforce best practices and avoid common mistakes when writing tests with Jest, which is a popular testing framework.

eslint-plugin-cypress

This plugin provides linting rules for Cypress, an end-to-end testing framework. It enforces best practices and consistency when writing tests with Cypress, similar to how eslint-plugin-testing-library does for Testing Library.

README

eslint-plugin-testing-library

ESLint plugin to follow best practices and anticipate common mistakes when writing tests with Testing Library

---

Installation

You'll first need to install ESLint:

$ npm i eslint --save-dev

Next, install eslint-plugin-testing-library:

$ npm install eslint-plugin-testing-library --save-dev

Note: If you installed ESLint globally (using the -g flag) then you must also install eslint-plugin-testing-library globally.

Usage

Add testing-library to the plugins section of your .eslintrc configuration file. You can omit the eslint-plugin- prefix:

{
  "plugins": ["testing-library"]
}

Then configure the rules you want to use under the rules section.

{
  "rules": {
    "testing-library/await-async-query": "error",
    "testing-library/no-await-sync-query": "error",
    "testing-library/no-debug": "warn"
  }
}

Shareable configurations

This plugin exports several recommended configurations that enforce good practices for specific Testing Library packages. You can find more info about enabled rules in the Supported Rules section within the Configurations column.

DOM Testing Library

Enforces recommended rules for DOM Testing Library.

To enable this configuration use the extends property in your .eslintrc config file:

{
  "extends": ["plugin:testing-library/dom"]
}

Angular

Enforces recommended rules for Angular Testing Library.

To enable this configuration use the extends property in your .eslintrc config file:

{
  "extends": ["plugin:testing-library/angular"]
}

React

Enforces recommended rules for React Testing Library.

To enable this configuration use the extends property in your .eslintrc config file:

{
  "extends": ["plugin:testing-library/react"]
}

Vue

Enforces recommended rules for Vue Testing Library.

To enable this configuration use the extends property in your .eslintrc config file:

{
  "extends": ["plugin:testing-library/vue"]
}

Supported Rules

Rule	Description	Configurations	Fixable
await-async-query	Enforce promises from async queries to be handled
await-async-utils	Enforce async utils to be awaited properly
await-fire-event	Enforce promises from fire event methods to be handled
consistent-data-testid	Ensure data-testid values match a provided regex.
no-await-sync-events	Disallow unnecessary await for sync events
no-await-sync-query	Disallow unnecessary await for sync queries
no-container	Disallow the use of container methods
no-debug	Disallow the use of debug
no-dom-import	Disallow importing from DOM Testing Library
no-manual-cleanup	Disallow the use of cleanup
no-multiple-assertions-wait-for	Disallow the use of multiple expect inside waitFor
no-node-access	Disallow direct Node access
no-promise-in-fire-event	Disallow the use of promises passed to a fireEvent method
no-render-in-setup	Disallow the use of render in setup functions
no-side-effects-wait-for	Disallow the use of side effects inside waitFor
no-wait-for-empty-callback	Disallow empty callbacks for waitFor and waitForElementToBeRemoved
no-wait-for-snapshot	Ensures no snapshot is generated inside of a waitFor call
no-wait-for-snapshot	Ensures no snapshot is generated inside of a waitFor call
prefer-explicit-assert	Suggest using explicit assertions rather than just getBy* queries
prefer-find-by	Suggest using findBy* methods instead of the waitFor + getBy queries
prefer-presence-queries	Enforce specific queries when checking element is present or not
prefer-user-event	Suggest using userEvent library instead of fireEvent for simulating user interaction
prefer-screen-queries	Suggest using screen while using queries
prefer-wait-for	Use waitFor instead of deprecated wait methods
render-result-naming-convention	Enforce a valid naming for return value from render

Contributors ✨

Thanks goes to these wonderful people (emoji key):

Mario Beltrán Alarcón 💻 📖 👀 ⚠️ 🚇 🐛	Thomas Lombart 💻 📖 👀 ⚠️ 🚇	Ben Monro 💻 📖 ⚠️	Nicola Molinari 💻 ⚠️ 📖 👀	Aarón García Hervás 📖	Matej Šnuderl 🤔 📖	Adrià Fontcuberta 💻 ⚠️
Jon Aldinger 📖	Thomas Knickman 💻 📖 ⚠️	Kevin Sullivan 📖	Jakub Jastrzębski 💻 📖 ⚠️	Nikolay Stoynov 📖	marudor 💻 ⚠️	Tim Deschryver 💻 📖 🤔 👀 ⚠️ 🐛 🚇 📦
Tobias Deekens 🐛	Victor Cordova 💻 ⚠️ 🐛	Dmitry Lobanov 💻 ⚠️	Kent C. Dodds 🐛	Gonzalo D'Elia 💻 ⚠️ 📖 👀	Jeff Rifwald 📖	Leandro Lourenci 🐛 💻 ⚠️
Miguel Erja González 🐛	Pavel Pustovalov 🐛	Jacob Parish 🐛 💻 ⚠️	Nick McCurdy 🤔 💻 👀	Stefan Cameron 🐛	Mateus Felix 💻 ⚠️ 📖	Renato Augusto Gama dos Santos 🤔 💻 📖 ⚠️
Josh Kelly 💻	Alessia Bellisario 💻 ⚠️ 📖	Spencer Miskoviak 💻 ⚠️ 📖 🤔	Giorgio Polvara 💻 ⚠️ 📖	Josh David 📖	Michaël De Boey 💻 📦 🚧	Jian Huang 💻 ⚠️ 📖

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