vitest-axe
Custom Vitest matcher for testing accessibility with aXe
This library is a fork of jest-axe
.
It shares that library's implementation and API. It is intended to make it
easier to include its matchers without clashes between Vitest and
Jest's environment or types.
See the README
for the original package for usage details.
[!IMPORTANT]
There is currently a bug in Happy DOM related to its implementation of Node.prototype.isConnected
. This causes compatibility issues with axe, which means that this library will not work if your Vitest environment is set to happy-dom
.
Installation
This module should be installed as one of your project's devDependencies
:
# with npm
npm install --save-dev vitest-axe
# yarn
yarn add --dev vitest-axe
# pnpm
pnpm add -D vitest-axe
Setup
Import vitest-axe/extend-expect
module
The simplest way to use this library is to import vitest-axe/extend-expect
from your test setup file.
// vitest-setup.js
import "vitest-axe/extend-expect";
Extend in test setup file
You can also import the matchers from vitest-axe/matchers
then pass them to
Vitest's expect.extend
method yourself:
// vitest-setup.js
import * as matchers from "vitest-axe/matchers";
import { expect } from "vitest";
expect.extend(matchers);
Extend in individual tests
import { axe, toHaveNoViolations } from "vitest-axe";
expect.extend(toHaveNoViolations);
it("should have no axe violations", async () => {
const html = "<html><!-- accessible markup! --></html>";
expect(await axe(html)).toHaveNoViolations();
});
With TypeScript
If you imported the vitest/extend-expect
module
in your setup file, you should be good to go. Make sure your setup file is
included in your tsconfig.json
.
If you do not import the vitest/extend-expect
module, you will need to augment Vitest's Assertion
and AsymmetricMatchersContaining
interfaces.
import "vitest";
import type { AxeMatchers } from "vitest-axe/matchers";
declare module "vitest" {
export interface Assertion extends AxeMatchers {}
export interface AsymmetricMatchersContaining extends AxeMatchers {}
}
Further reading:
Usage
import { axe } from "vitest-axe";
it("should demonstrate this matcher's usage", async () => {
const render = () => '<img src="#"/>';
// pass anything that outputs html to axe
const html = render();
expect(await axe(html)).toHaveNoViolations();
});