Function writerClosedPromise

lib/internal/webstreams/writablestream.js:643–665

(writer)

// otherwise it follows the stream state. The settle sites only touch the
// record when it has been materialized.
function writerClosedPromise(writer) {
  let close = writer[kState].close;
  if (close === undefined) {
    const stream = writer[kState].stream;
    if (stream === undefined) {
      close = rejectedHandledRecord(lazyWritableReleasedError());
    } else {
      switch (stream[kState].state) {
        case 'writable':
        case 'erroring':
          close = PromiseWithResolvers();
          break;
        case 'closed':
          close = resolvedRecord();
          break;
        default:
          close = rejectedHandledRecord(stream[kState].storedError);
      }
    }
    writer[kState].close = close;
  }
  return close;
}

// Same as writerClosedPromise(), for the writer's [[readyPromise]]. The
// pending epoch is derivable too: a writable stream with backpressure and