/**
 * @license Copyright 2017 The Lighthouse Authors. All Rights Reserved.
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */
'use strict';

/**
 * @fileoverview Ensures <img> elements have alternate text or a role of none or presentation.
 * See base class in axe-audit.js for audit() implementation.
 */

const AxeAudit = require('./axe-audit.js');
const i18n = require('../../lib/i18n/i18n.js');

const UIStrings = {
  /** Title of an accesibility audit that evaluates if all image elements have the alt HTML attribute to describe their contents. This title is descriptive of the successful state and is shown to users when no user action is required. */
  title: 'Image elements have `[alt]` attributes',
  /** Title of an accesibility audit that evaluates if all image elements have the alt HTML attribute to describe their contents. This title is descriptive of the failing state and is shown to users when there is a failure that needs to be addressed. */
  failureTitle: 'Image elements do not have `[alt]` attributes',
  /** Description of a Lighthouse audit that tells the user *why* they should try to pass. This is displayed after a user expands the section to see more. No character length limits. 'Learn More' becomes link text to additional documentation. */
  description: 'Informative elements should aim for short, descriptive alternate text. ' +
      'Decorative elements can be ignored with an empty alt attribute. ' +
      '[Learn more](https://web.dev/image-alt/).',
};

const str_ = i18n.createMessageInstanceIdFn(__filename, UIStrings);

class ImageAlt extends AxeAudit {
  /**
   * @return {LH.Audit.Meta}
   */
  static get 
() {
    return {
      id: 'image-alt',
      title: str_(UIStrings.title),
      failureTitle: str_(UIStrings.failureTitle),
      description: str_(UIStrings.description),
      requiredArtifacts: ['Accessibility'],
    };
  }
}

module.exports = ImageAlt;
module.exports.UIStrings = UIStrings;

meta