Accessibility Testing in Storybook

Storybook allows you to conduct accessibility audits on your stories using the @storybook/addon-a11y addon. Let’s get it up and running.

npx storybook@latest add @storybook/addon-a11y

This will add a new tab to your addon pane that will show you any issues that your component might have. Under the hood, it’s using axe-core to run the audit.

From the axe-core README.md:

With axe-core, you can find on average 57% of WCAG issues automatically. Additionally, axe-core will return elements as “incomplete” where axe-core could not be certain, and manual review is needed.

Running Accessibility Audits as Part of Your Test Suite

There is an integration between Axe and Playwright called—unsurprisingly—axe-playwright. What’s super cool is that Storybook can spin up Playwright and run these tests for you with it’s test runner.

Dependencies

You’ll need to install axe-playwright if it’s not already installed. You can take care of that by running npm install axe-playwright --save-dev.

Also, if this is your first rodeo with Playwright in your project, you’ll need to install its browsers. You can take care of this by running npx playwright install.

In .storybook/test-runner.ts, you can set up the following configuration.

import type { TestRunnerConfig } from '@storybook/test-runner';
import { injectAxe, checkA11y } from 'axe-playwright';

const config: TestRunnerConfig = {
	async preVisit(page) {
		await injectAxe(page);
	},
	async postVisit(page) {
		await checkA11y(page, '#storybook-root', {
			detailedReport: true,
			detailedReportOptions: {
				html: true,
			},
		});
	},
};

export default config;

Now, when you run npx test-storybook, it will also check for accessibility violations as well.

Steve Kinney

Building Design Systems with Storybook

Running Accessibility Audits as Part of Your Test Suite