is-experiment-on.js

/**
 * Copyright 2018 The AMP HTML 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';

module.exports = function (context) {
  const isExperimentOn = 'CallExpression[callee.name=isExperimentOn]';
  const message = 'isExperimentOn must be passed an explicit string';

  return {
    [isExperimentOn](node) {
      const arg = node.arguments[1];
      if (!arg) {
        context.report({node, message});
        return;
      }

      const comments = context.getCommentsBefore(arg);
      const ok = comments.some((comment) => comment.value === 'OK');
      if (ok) {
        return;
      }

      if (arg.type === 'Literal' && typeof arg.value === 'string') {
        return;
      }

      context.report({node, message});
    },
  };
};