playwright/src/rpc/client/stream.ts

/**
 * Copyright (c) Microsoft Corporation.
 *
 * 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.
 */

import { Readable } from 'stream';
import { StreamChannel, StreamInitializer } from '../channels';
import { ChannelOwner } from './channelOwner';

export class Stream extends ChannelOwner<StreamChannel, StreamInitializer> {
  static from(Stream: StreamChannel): Stream {
    return (Stream as any)._object;
  }

  constructor(parent: ChannelOwner, type: string, guid: string, initializer: StreamInitializer) {
    super(parent, type, guid, initializer);
  }

  stream(): Readable {
    return new StreamImpl(this._channel);
  }
}

class StreamImpl extends Readable {
  private _channel: StreamChannel;

  constructor(channel: StreamChannel) {
    super();
    this._channel = channel;
  }

  async _read(size: number) {
    const data = await this._channel.read({ size });
    if (data)
      this.push(Buffer.from(data, 'base64'));
    else
      this.push(null);
  }
}