Fetch Upload Streaming とは Fetch Upload Streaming とは、ブラウザの JavaScript の POST リクエストで HTTP のストリーミングを行える機能です。より具体的には、Fetch API の body に ReadableStream や WritableStream のような Streams API を渡せるようになります。 const stream = new ReadableStream({}) fetch(`/send?room=${roomId}`, { method: "POST", body: stream, duplex: "half", }); かねてより Fetch API ではレスポンスを ReadableStream で取得できたのですが、反対にリクエスト時に body に ReadableStream を渡
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