React A11y

Warns about potential accessibility issues with your React elements.

Installation

Run:

npm install react-a11y

Usage

In your main application file, require the module and call it, you'll start
getting warnings in the console as your app renders. Note that by default all
rules are turned off so you need to turn them on first (by setting them to
"warn" or "error").

import React    from 'react';
import ReactDOM from 'react-dom';

if (process.env.NODE_ENV === 'development') {
  const a11y = require('react-a11y').default;
  a11y(React, ReactDOM, {
    rules: {
      'img-uses-alt': 'warn',
      'redundant-alt': [ 'warn', [ 'image', 'photo', 'foto', 'bild' ]]
    // ...
    }
  });
}

You probably don't want to call it if you're in production, since it patches the
React rendering functions and this might make this slower.

Options

These are the supported configuration options, annotated using [flow][] type
annotations

a11y(React : React, ReactDOM : ReactDOM, opts : object? );

React is the React object you want to shim to allow the
accessibility tests.

ReactDOM is the ReactDOM object you're using to render the
React components. This is only used on the client side, so you
can safely omit it when using react-a11y in node.

options:

  • plugins : [string]
    An array of strings corresponding to names of plugins to be used.
    Eg. if the array contains 'aria-wai' it would include the rules
    in a (yet to be written) react-a11y-plugin-aria-wai module. You
    are responsible for installing this module.

  • rules : object
    The configuration options for each of the rules. This uses the same format
    as [eslint][] does:

    const rules = {
  'img-uses-alt': 'off',
  'redundant-alt': [
    'warn',
    // other options to pass to the rule:
    [
      'foto'
    ]
  ]
};

    Refer to the rule docs
    to see what options are defined for each rule.

  • reporter : object => undefined
    Use this to modify how the warnings are displayed.
    The reporter is a function that accepts an object with
    the following keys:

    • msg : string - the error message
    • tagName : string - the tagName of the violating element (eg. 'img')
    • severity : string - the severity as configured by the user in the
      corresponding rule configuration (one of 'off', 'warn', or 'error')
    • props : object - the props as passed to the element
    • displayName : string? - the displayName of the owner, if any
    • DOMNode : object? - the violating DOMNode as rendered to the browser
      DOM, this is only available on when react-a11y is running in the
      browser.
    • url : string? - The url to a webpage explaining why this rule
      is important

    The default reporter displays all the information it can, but listens
    to the deprecated options includeSrcNode, warningPrefix and
    throwErro and throwError.

  • filterFn : (string, string, string) => boolean
    You can filter failures by passing a function to the filterFn option. The
    filter function will receive three arguments: the name of the Component
    instance or ReactElement, the id of the violating element, and the failure
    message.

    Note: If it is a ReactElement, the name will be the node type (eg. div)

    // only show errors on CommentList
const commentListFailures = function (name, id, msg) {
  return name === "CommentList";
};

a11y(React, ReactDOM, { filterFn: commentListFailures });

Cleaning Up In Tests

Use the restoreAll() method to clean up mutations made to React.
Useful if you are using react-a11y in your test suite:

beforeEach(() => a11y(React));
afterEach(() => a11y.restoreAll());

GitHub