Function readResponseStreamToBlob

src/utils/urlUtils.ts:156–182

* Read a fetch response body to a Blob, reporting bytes as they arrive. Builds * the Blob directly from the chunk array (no intermediate full-buffer copy) to * keep peak memory near one copy of the file.

(
  body: ReadableStream<Uint8Array>,
  total: number,
  onProgress: DownloadProgressCallback
)

 * keep peak memory near one copy of the file.
 */
async function readResponseStreamToBlob(
  body: ReadableStream<Uint8Array>,
  total: number,
  onProgress: DownloadProgressCallback
): Promise<Blob> {
  const reader = body.getReader();
  const chunks: Uint8Array<ArrayBuffer>[] = [];
  let loaded = 0;
  onProgress(0, total);
  try {
    for (;;) {
      const { done, value } = await reader.read();
      if (done) break;
      // Copy into an ArrayBuffer-backed view: detaches from the stream buffer and
      // satisfies the BlobPart type (the raw chunk is Uint8Array<ArrayBufferLike>).
      chunks.push(new Uint8Array(value));
      loaded += value.length;
      onProgress(loaded, total);
    }
  } finally {
    // Tear down the stream if the loop exits abnormally (read rejection, or a
    // throwing progress callback) so the underlying connection isn't left open.
    // A no-op once the stream is fully drained or already errored.
    reader.cancel().catch(() => {});
  }
  return new Blob(chunks);
}

/**
 * Extract filename from a URL path, percent-decoded so it matches the