Translate ReadableStreamDefaultReader to Node.js stream.Readable

translate-stream.js

/**
 * Translate ReadableStreamDefaultReader to Node.js stream.Readable
 * @author SourceBoy
 * @license MIT
 */

async function pump(rs, _rs) {
  const { done, value } = await rs.read();
  if (done) {
    _rs.push(null);
    return _rs;
  }
  const result = _rs.push(value);
  if (!result) {
    await new Promise((resolve) => {
      _rs.once('read', resolve);
    }); 
  }
  return pump(rs, _rs);
}

fetch('/somewhere').then((response) => {
  const rs = response.body.getReader();
  const _rs = new stream.Readable({
    read(size) {
      this.emit('read', size);
    }
  });
  return pump(rs, _rs);
});