Function waitForDrain

packages/cli/src/cloud/download.ts:105–135

* Resolve when the write stream emits `drain`, or reject on `error` / * `close` / signal abort — avoids the hang from awaiting a one-shot * `drain` event that never fires because the stream tore down first.

(file: NodeJS.WritableStream, signal?: AbortSignal)

 * `drain` event that never fires because the stream tore down first.
 */
function waitForDrain(file: NodeJS.WritableStream, signal?: AbortSignal): Promise<void> {
  return new Promise<void>((resolve, reject) => {
    const cleanup = () => {
      file.off("drain", onDrain);
      file.off("error", onError);
      file.off("close", onClose);
      signal?.removeEventListener("abort", onAbort);
    };
    const onDrain = (): void => {
      cleanup();
      resolve();
    };
    const onError = (err: Error): void => {
      cleanup();
      reject(err);
    };
    const onClose = (): void => {
      cleanup();
      reject(new Error("write stream closed before drain"));
    };
    const onAbort = (): void => {
      cleanup();
      const reason = signal?.reason;
      reject(reason instanceof Error ? reason : new Error("Download aborted"));
    };
    file.once("drain", onDrain);
    file.once("error", onError);
    file.once("close", onClose);
    signal?.addEventListener("abort", onAbort, { once: true });
  });
}

function closeFile(file: NodeJS.WritableStream): Promise<void> {
  return new Promise<void>((resolve) => {