interactive-supports-focus.js

/**
 * @fileoverview Enforce that elements with onClick handlers must be tabbable.
 * @author Ethan Cohen
 * @flow
 */

import {
  dom,
  roles,
} from 'aria-query';
import {
  getProp,
  elementType,
  eventHandlersByType,
  getLiteralPropValue,
  hasAnyProp,
} from 'jsx-ast-utils';
import type { JSXOpeningElement } from 'ast-types-flow';
import includes from 'array-includes';
import type { ESLintConfig, ESLintContext, ESLintVisitorSelectorConfig } from '../../flow/eslint';
import {
  enumArraySchema,
  generateObjSchema,
} from '../util/schemas';
import isDisabledElement from '../util/isDisabledElement';
import isHiddenFromScreenReader from '../util/isHiddenFromScreenReader';
import isInteractiveElement from '../util/isInteractiveElement';
import isInteractiveRole from '../util/isInteractiveRole';
import isNonInteractiveElement from '../util/isNonInteractiveElement';
import isNonInteractiveRole from '../util/isNonInteractiveRole';
import isPresentationRole from '../util/isPresentationRole';
import getTabIndex from '../util/getTabIndex';

// ----------------------------------------------------------------------------
// Rule Definition
// ----------------------------------------------------------------------------

const schema = generateObjSchema({
  tabbable: enumArraySchema([...roles.keys()]
    .filter((name) => !roles.get(name).abstract)
    .filter((name) => roles.get(name).superClass.some((klasses) => includes(klasses, 'widget')))),
});
const domElements = [...dom.keys()];

const interactiveProps = [
  ...eventHandlersByType.mouse,
  ...eventHandlersByType.keyboard,
];

module.exports = ({
  meta: {
    docs: {
      url: 'https://github.com/evcohen/eslint-plugin-jsx-a11y/tree/master/docs/rules/interactive-supports-focus.md',
    },
    schema: [schema],
  },

  create: (context: ESLintContext): ESLintVisitorSelectorConfig => ({
    JSXOpeningElement: (node: JSXOpeningElement) => {
      const tabbable = (
        context.options && context.options[0] && context.options[0].tabbable
      ) || [];
      const { attributes } = node;
      const type = elementType(node);
      const hasInteractiveProps = hasAnyProp(attributes, interactiveProps);
      const hasTabindex = getTabIndex(getProp(attributes, 'tabIndex')) !== undefined;

      if (!includes(domElements, type)) {
        // Do not test higher level JSX components, as we do not know what
        // low-level DOM element this maps to.
        return;
      }
      if (
        !hasInteractiveProps
        || isDisabledElement(attributes)
        || isHiddenFromScreenReader(type, attributes)
        || isPresentationRole(type, attributes)
      ) {
        // Presentation is an intentional signal from the author that this
        // element is not meant to be perceivable. For example, a click screen
        // to close a dialog .
        return;
      }

      if (
        hasInteractiveProps
        && isInteractiveRole(type, attributes)
        && !isInteractiveElement(type, attributes)
        && !isNonInteractiveElement(type, attributes)
        && !isNonInteractiveRole(type, attributes)
        && !hasTabindex
      ) {
        const role = getLiteralPropValue(getProp(attributes, 'role'));
        if (includes(tabbable, role)) {
          // Always tabbable, tabIndex = 0
          context.report({
            node,
            message: `Elements with the '${role}' interactive role must be tabbable.`,
          });
        } else {
          // Focusable, tabIndex = -1 or 0
          context.report({
            node,
            message: `Elements with the '${role}' interactive role must be focusable.`,
          });
        }
      }
    },
  }),
}: ESLintConfig);