@axe-core/playwright

What is @axe-core/playwright?

@axe-core/playwright is an accessibility testing library that integrates with Playwright to automate accessibility checks. It leverages the axe-core engine to analyze web pages and identify accessibility issues, making it easier for developers to ensure their applications are accessible to all users.

What are @axe-core/playwright's main functionalities?

Basic Accessibility Scan

This feature allows you to perform a basic accessibility scan on a web page. The code sample demonstrates how to launch a browser, navigate to a page, inject the axe-core script, and run an accessibility check.

const { chromium } = require('playwright');
const { injectAxe, checkA11y } = require('@axe-core/playwright');

(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
  await injectAxe(page);
  const results = await checkA11y(page);
  console.log(results);
  await browser.close();
})();

Customizing Axe-core Options

This feature allows you to customize the axe-core options for the accessibility scan. The code sample shows how to specify which WCAG levels to check for during the scan.

const { chromium } = require('playwright');
const { injectAxe, checkA11y } = require('@axe-core/playwright');

(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
  await injectAxe(page);
  const options = { runOnly: { type: 'tag', values: ['wcag2a', 'wcag2aa'] } };
  const results = await checkA11y(page, null, options);
  console.log(results);
  await browser.close();
})();

Excluding Elements from Scan

This feature allows you to exclude specific elements from the accessibility scan. The code sample demonstrates how to exclude elements with a specific class from being checked.

const { chromium } = require('playwright');
const { injectAxe, checkA11y } = require('@axe-core/playwright');

(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
  await injectAxe(page);
  const exclude = ['.ignore-this-element'];
  const results = await checkA11y(page, null, null, exclude);
  console.log(results);
  await browser.close();
})();

Other packages similar to @axe-core/playwright

pa11y

Pa11y is an automated accessibility testing tool that runs accessibility tests on web pages and reports issues. It is similar to @axe-core/playwright in that it helps identify accessibility issues, but it does not integrate directly with Playwright. Instead, it can be used as a standalone CLI tool or integrated into other testing frameworks.

cypress-axe

Cypress-axe is a plugin for Cypress that allows you to run axe-core accessibility checks within your Cypress tests. It is similar to @axe-core/playwright in that it uses the axe-core engine for accessibility testing, but it is designed to work with the Cypress testing framework instead of Playwright.

axe-webdriverjs

Axe-webdriverjs is a library that integrates axe-core with Selenium WebDriver for automated accessibility testing. It is similar to @axe-core/playwright in that it uses the axe-core engine, but it is designed to work with Selenium WebDriver instead of Playwright.

README

@axe-core/playwright

Provides a chainable axe API for playwright and automatically injects into all frames

Getting Started

Install Node.js if you haven't already.

Install Playwright: npm install playwright

Install @axe-core/playwright: npm install @axe-core/playwright

Usage

This module uses a chainable API to assist in injecting, configuring, and analyzing axe with Playwright. As such, it is required to pass an instance of Playwright.

Here is an example of a script that will drive Playwright to a page, perform an analysis, and then log results to the console.

const { AxeBuilder } = require('@axe-core/playwright');
const playwright = require('playwright');

(async () => {
  const browser = await playwright.chromium.launch({ headless: true });
  const context = await browser.newContext();
  const page = await context.newPage();
  await page.goto('https://dequeuniversity.com/demo/mars/');

  try {
    const results = await new AxeBuilder({ page }).analyze();
    console.log(results);
  } catch (e) {
    // do something with the error
  }

  await browser.close();
})();

AxeBuilder({ page: Playwright.Page })

Constructor for the AxeBuilder helper. You must pass an instance of Playwright as the first argument.

const builder = new AxeBuilder({ page });

AxeBuilder#analyze(): Promise<axe.Results | Error>

Performs analysis and passes any encountered error and/or the result object.

new AxeBuilder({ page })
  .analyze()
  .then(results => {
    console.log(results);
  })
  .catch(e => {
    // Do something with error
  });

AxeBuilder#include(selector: String | String[])

Adds a CSS selector to the list of elements to include in analysis

new AxeBuilder({ page }).include('.results-panel');

Method chaining is also available, add multiple CSS selectors to the list of elements to include in analysis

new AxeBuilder({ page })
  .include('.selector-one')
  .include('.selector-two')
  .include('.selector-three');

Note: arrays with more than one index when passing multiple CSS selectors are not currently supported example: .include(['#foo', '#bar', '#baz'])

AxeBuilder#exclude(selector: String | String[])

Add a CSS selector to the list of elements to exclude from analysis

new AxeBuilder({ page }).exclude('.another-element');

Method chaining is also available, add multiple CSS selectors to the list of elements to exclude from analysis

new AxeBuilder({ page })
  .exclude('.selector-one')
  .exclude('.selector-two')
  .exclude('.selector-three');

Note: arrays with more than one index when passing multiple CSS selectors are not currently supported example: .exclude(['#foo', '#bar', '#baz'])

AxeBuilder#options(options: axe.RunOptions)

Specifies options to be used by axe.run. Will override any other configured options. including calls to AxeBuilder#withRules() and AxeBuilder#withTags(). See axe-core API documentation for information on its structure.

new AxeBuilder({ page }).options({ checks: { 'valid-lang': ['orcish'] } });

AxeBuilder#withRules(rules: String|Array)

Limits analysis to only those with the specified rule IDs. Accepts a String of a single rule ID or an Array of multiple rule IDs. Subsequent calls to AxeBuilder#options, AxeBuilder#withRules or AxeBuilder#withRules will override specified options.

new AxeBuilder({ page }).withRules('html-lang');

new AxeBuilder({ page }).withRules(['html-lang', 'image-alt']);

AxeBuilder#withTags(tags: String|Array)

Limits analysis to only those with the specified rule IDs. Accepts a String of a single tag or an Array of multiple tags. Subsequent calls to AxeBuilder#options, AxeBuilder#withRules or AxeBuilder#withRules will override specified options.

new AxeBuilder({ page }).withTags('wcag2a');

new AxeBuilder({ page }).withTags(['wcag2a', 'wcag2aa']);

AxeBuilder#disableRules(rules: String|Array)

Skips verification of the rules provided. Accepts a String of a single rule ID or an Array of multiple rule IDs. Subsequent calls to AxeBuilder#options, AxeBuilder#disableRules will override specified options.

new AxeBuilder({ page }).disableRules('color-contrast');

AxeBuilder#setLegacyMode(legacyMode: boolean = true)

Set the frame testing method to "legacy mode". In this mode, axe will not open a blank page in which to aggregate its results. This can be used in an environment where opening a blank page is causes issues.

With legacy mode turned on, axe will fall back to its test solution prior to the 4.3 release, but with cross-origin frame testing disabled. The frame-tested rule will report which frames were untested.

Important Use of .setLegacyMode() is a last resort. If you find there is no other solution, please report this as an issue.

const axe = new AxeBuilder({ page }).setLegacyMode();
const result = await axe.analyze();
axe.setLegacyMode(false); // Disables legacy mode