A Blob can be constructed from an array of "chunks", where each chunk is a string, binary data structure, or another Blob.
const buf = new ArrayBuffer(64);
const blob = new Blob([buf]);
By default the type of the resulting Blob will be unset. This can be set manually.
const buf = new ArrayBuffer(64);
const blob = new Blob([buf], { type: "application/octet-stream" });
blob.type; // => "application/octet-stream"
See Docs > API > Binary Data for complete documentation on manipulating binary data with Bun.