d2-ui/node_modules-react-15/eslint-plugin-jsx-a11y/lib/rules/img-has-alt.js

d2-ui

/**
 * @fileoverview Enforce img tag uses alt attribute.
 * @author Ethan Cohen
 */
'use strict';

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

var _getAttribute = require('../util/getAttribute');

var _getAttribute2 = _interopRequireDefault(_getAttribute);

var _getAttributeValue = require('../util/getAttributeValue');

var _getAttributeValue2 = _interopRequireDefault(_getAttributeValue);

var _getNodeType = require('../util/getNodeType');

var _getNodeType2 = _interopRequireDefault(_getNodeType);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

module.exports = function (context) {
  return {
    JSXOpeningElement: function JSXOpeningElement(node) {
      var typeCheck = ['img'].concat(context.options[0]);
      var nodeType = (0, _getNodeType2.default)(node);

      // Only check 'img' elements and custom types.
      if (typeCheck.indexOf(nodeType) === -1) {
        return;
      }

      var roleProp = (0, _getAttribute2.default)(node.attributes, 'role');
      var roleValue = (0, _getAttributeValue2.default)(roleProp);
      var isPresentation = roleProp && typeof roleValue === 'string' && roleValue.toLowerCase() === 'presentation';

      if (isPresentation) {
        return;
      }

      var altProp = (0, _getAttribute2.default)(node.attributes, 'alt');

      // Missing alt prop error.
      if (altProp === undefined) {
        context.report({
          node: node,
          message: nodeType + ' elements must have an alt prop or use role="presentation".'
        });
        return;
      }

      // Check if alt prop is undefined.
      var altValue = (0, _getAttributeValue2.default)(altProp);
      var isNullValued = altProp.value === null; // <img alt />

      if (altValue && !isNullValued || altValue === '') {
        return;
      }

      // Undefined alt prop error.
      context.report({
        node: node,
        message: 'Invalid alt value for ' + nodeType + '. Use alt="" or role="presentation" for presentational images.'
      });
    }
  };
};

module.exports.schema = [{
  'oneOf': [{ 'type': 'string' }, {
    'type': 'array',
    'items': {
      'type': 'string'
    },
    'minItems': 1,
    'uniqueItems': true
  }]
}];