/* Copyright 2017 Mozilla Foundation
 *
 * 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.
 */

let isReadableStreamSupported = false;
if (typeof ReadableStream !== 'undefined') {
  // MS Edge may say it has ReadableStream but they are not up to spec yet.
  try {
    // eslint-disable-next-line no-new
    new ReadableStream({
      start(controller) {
        controller.close();
      },
    });
    isReadableStreamSupported = true;
  } catch (e) {
    // The ReadableStream constructor cannot be used.
  }
}
if (isReadableStreamSupported) {
  exports.ReadableStream = ReadableStream;
} else {
  exports.ReadableStream =
    require('../../external/streams/streams-lib').ReadableStream;
}