Function streamUrlToFile

src/lib/bundle.ts:699–748

(
  url: string,
  filePath: string,
  fetchImpl: FetchImpl,
)

 * snapshots.
 */
export async function streamUrlToFile(
  url: string,
  filePath: string,
  fetchImpl: FetchImpl,
): Promise<void> {
  let response: Response;
  try {
    response = await fetchImpl(url);
  } catch (err) {
    const message = err instanceof Error ? err.message : String(err);
    throw new TransportError(`Failed to download presigned URL ${url}: ${message}`);
  }
  if (!response.ok) {
    throw ApiError.fromEnvelope({
      error: {
        code: 'UNAVAILABLE',
        message: `Failed to download presigned URL (HTTP ${response.status}).`,
        nextAction:
          'Re-run `testsprite test failure get`. Presigned URLs in the bundle expire after 15 minutes.',
        requestId: 'local',
        details: { status: response.status, url },
      },
    });
  }
  if (!response.body) {
    // Some test runtimes / fetch polyfills don't expose `body` as a
    // ReadableStream. Fall back to a buffered write — same correctness,
    // just no streaming benefit. The bundle is bounded by the
    // backend's 15-min TTL, so even a multi-MB video buffers fully in
    // a tolerable amount of memory.
    const buffer = Buffer.from(await response.arrayBuffer());
    await writeFile(filePath, buffer);
    return;
  }
  await mkdir(dirname(filePath), { recursive: true });
  // `response.body` is a Web ReadableStream. Node's `pipeline` accepts
  // it via `Readable.fromWeb` (Node ≥ 18). Wrap in a try so any error
  // from the stream propagates as a TransportError, preserving the
  // exit-code contract.
  const fileSink = createWriteStream(filePath);
  try {
    const webBody = response.body as unknown as NodeReadableStream<Uint8Array>;
    const { Readable } = await import('node:stream');
    const nodeStream = Readable.fromWeb(webBody);
    await pipeline(nodeStream, fileSink as unknown as Writable);
  } catch (err) {
    const message = err instanceof Error ? err.message : String(err);
    throw new TransportError(`Failed mid-download of ${url}: ${message}`);
  }
}

function isPresignedUrl(value: string): boolean {
  return value.startsWith('https://');