Memo
Browser 中，dataURL 与 ArrayBuffer 互转
Browser 中，dataURL 与 ArrayBuffer 互转
const dataURL =
`data:${file.mimeType};base64,${btoa(
String.fromCharCode(...new Uint8Array(buffer)),
)}`;
const buffer = fetch(url) .then(res => res.arrayBuffer());
const dataURL =
`data:${file.mimeType};base64,${btoa(
String.fromCharCode(...new Uint8Array(buffer)),
)}`;
const buffer = fetch(url) .then(res => res.arrayBuffer());