What is @testing-library/dom?
The @testing-library/dom package is a lightweight solution for testing DOM nodes (whether they are part of a web browser environment or not) in a way that simulates user actions. It aims to test the functionality of components in a user-centric manner. This library is part of the larger Testing Library ecosystem, which provides tools and utilities to work with React, Vue, Angular, and other frameworks by extending the base functionality provided in @testing-library/dom.
What are @testing-library/dom's main functionalities?
Querying DOM Elements
Allows querying DOM elements using text content, which simulates how users find elements on the page. This is useful for ensuring elements are present and contain the correct content.
const { getByText } = require('@testing-library/dom');
const element = getByText(document.body, 'Hello World');
Firing Events
Simulates user actions by firing events on DOM elements. This is crucial for testing interactive elements like buttons and forms.
const { fireEvent } = require('@testing-library/dom');
fireEvent.click(document.querySelector('button'));
Waiting for Elements
Provides utilities to wait for elements to appear or change, which is useful for testing asynchronous behavior like data fetching or animations.
const { waitFor } = require('@testing-library/dom');
await waitFor(() => getByText(document.body, 'Loaded'));
Other packages similar to @testing-library/dom
enzyme
Enzyme is a JavaScript Testing utility for React that makes it easier to test your React Components' output. It allows you to manipulate, traverse, and in some ways simulate runtime given the output. Enzyme's API is more focused on React specifically compared to @testing-library/dom which is framework-agnostic.
cypress
Cypress is a front end testing tool built for the modern web. It is built on a new architecture and runs in the same run-loop as the application being tested. Cypress also acts as an end-to-end testing framework, unlike @testing-library/dom which is more focused on unit and integration tests.
selenium-webdriver
Selenium WebDriver is a browser automation library. Most often used for testing web-applications, Selenium allows you to perform tasks as if you were the user of the application. It's more comprehensive for end-to-end testing across different browsers compared to @testing-library/dom which is more lightweight and focused on simulating user actions in a testing environment.
DOM Testing Library
Simple and complete DOM testing utilities that encourage good testing
practices.
Read the docs |
Edit the docs
Table of Contents
The Problem
You want to write maintainable tests for your Web UI. 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 DOM Testing Library
is a very light-weight solution for testing DOM nodes
(whether simulated with JSDOM
as provided by
default with Jest or in the browser). The main utilities it provides involve
querying the DOM for nodes in a way that's similar to how the user finds
elements on the page. In this way, the library helps ensure your tests give you
confidence in your UI code. The DOM Testing Library
's 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
:
npm install --save-dev @testing-library/dom
Docs
Documentation
Read the docs (and discover framework and tool-specific implementations) at
testing-library.com
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 web pages are used.
Utilities are included in this project based on the following guiding
principles:
- If it relates to rendering components, it deals with DOM nodes rather than
component instances, nor should it encourage dealing with component
instances.
- It should be generally useful for testing the application components in the
way the user would use it. We are making some trade-offs here because
we're using a computer and often a simulated browser environment, but in
general, utilities should encourage tests that use the components the way
they're intended to be used.
- 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):
This project follows the all-contributors specification.
Contributions of any kind welcome!
LICENSE
MIT