axe-testing-library

Extensions for automated aXe accessibility testing for popular test tooling.

Features

• Test matchers for Jest, Vitest, and Playwright
• One-line setup
• Customizable with full access to aXe's run options if needed
• TypeScript types included

Support for more testing tools like Cypress, Puppeteer, Jasmine, and Mocha are planned to be added!

Installation

1npm install --save-dev axe-testing-library

This library assumes you have already installed the dependencies required by the test framework you are using. For Jest and Vite, you must be using JSDOM as the test environment. This is on by default with Jest, but Vitest requires a configuration change.

Usage

This library provides an entrypoint for each supported testing framework. Import the one you need.

Jest

1import { toBeAccessible } from "axe-testing-library/jest";
2
3expect.extend({ toBeAccessible });
4
5test("should be accessible", async () => {
6  const htmlString = `
7    <main>
8      <h1>Hello World</h1>
9      <img src="example.jpg" alt="Example image">
10      <button>Click</button>
11    </main>
12  `;
13
14  await expect(htmlString).toBeAccessible();
15});
16
17// Usage with React Testing Library
18import { render } from "@testing-library/react";
19
20test("should work with react", async () => {
21  const { container } = render(<MyComponent />);
22  await expect(container).toBeAccessible();
23});

Vitest

1import { toBeAccessible } from "axe-testing-library/vitest";
2import { it, expect } from "vitest";
3
4expect.extend({ toBeAccessible });
5
6it("should be accessible", async () => {
7  const htmlString = `
8    <main>
9      <h1>Hello World</h1>
10      <img src="example.jpg" alt="Example image">
11      <button>Click</button>
12    </main>
13  `;
14  await expect(htmlString).toBeAccessible();
15});

A note about JSDOM

aXe internally creates a canvas instance when it runs, so you may see not implemented warnings in your console:

1Error: Not implemented: HTMLCanvasElement.prototype.getContext (without installing the canvas npm package)

You can install a mock yourself, or mock them yourself:

1// vitest.setup.ts
2import { vi } from "vitest";
3HTMLCanvasElement.prototype.getContext = vi.fn();
4
5// jest.setup.ts
6HTMLCanvasElement.prototype.getContext = jest.fn();

Playwright

1import { toBeAccessible } from "axe-testing-library/playwright";
2import { test, expect as baseExpect } from "@playwright/test";
3
4const expect = baseExpect.extend({ toBeAccessible });
5
6test("should be accessible", async ({ page }) => {
7  await expect(page).toBeAccessible();
8});

Example Output

For each accessibility violation you have, axe-testing-library will report the violation message along with a link to the rule. It also provide the rule id.

Configuration

Pass axe run options to customize checks:

1// Turn off the region rule
2await expect(document.body).toBeAccessible({
3  rules: { region: { enabled: false } },
4});

You can see the full list of rules here.

Contributing

See CONTRIBUTING.md for how to report issues or submit changes.

License

MIT © Peak Software