LineReader TransformStream

line-reader-transform-stream.js

lineReader = () => {
  let buffer = "";

  return new TransformStream({
    transform(chunk, controller) {
      buffer += chunk;
      const parts = buffer.split("\n");
      parts.slice(0, -1).forEach((part) => controller.enqueue(part));
      buffer = parts[parts.length - 1];
    },
    flush(controller) {
      if (buffer) controller.enqueue(buffer);
    }
  });
}