Streaming jobs with SSE

for await (const event of reader.stream(jobId)) {
  switch (event.type) {
    case "progress":
      console.log(`${event.completed}/${event.total}`);
      break;
    case "page":
      console.log("page done:", event.data.url);
      break;
    case "error":
      console.error("page failed:", event.url, event.error);
      break;
    case "done":
      console.log("job finished:", event.status);
      return;
  }
}

const res = await fetch(`https://api.reader.dev/v1/jobs/${jobId}/stream`, {
  headers: { "x-api-key": process.env.READER_KEY! },
});

const reader = res.body!.pipeThrough(new TextDecoderStream()).getReader();
let buffer = "";

while (true) {
  const { value, done } = await reader.read();
  if (done) break;
  buffer += value;

  // SSE frames are separated by blank lines
  let idx;
  while ((idx = buffer.indexOf("\n\n")) !== -1) {
    const frame = buffer.slice(0, idx);
    buffer = buffer.slice(idx + 2);

    const eventMatch = frame.match(/^event: (.*)$/m);
    const dataMatch = frame.match(/^data: (.*)$/m);
    if (eventMatch && dataMatch) {
      const type = eventMatch[1];
      const data = JSON.parse(dataMatch[1]);
      console.log(type, data);
    }
  }
}