Function writerReadyPromise

lib/internal/webstreams/writablestream.js:670–694

(writer)

// pending epoch is derivable too: a writable stream with backpressure and
// no queued close has a pending ready promise.
function writerReadyPromise(writer) {
  let ready = writer[kState].ready;
  if (ready === undefined) {
    const stream = writer[kState].stream;
    if (stream === undefined) {
      ready = rejectedHandledRecord(lazyWritableReleasedError());
    } else {
      switch (stream[kState].state) {
        case 'writable':
          ready = !writableStreamCloseQueuedOrInFlight(stream) &&
                  stream[kState].backpressure ?
            PromiseWithResolvers() :
            resolvedRecord();
          break;
        case 'closed':
          ready = resolvedRecord();
          break;
        default:
          ready = rejectedHandledRecord(stream[kState].storedError);
      }
    }
    writer[kState].ready = ready;
  }
  return ready;
}

function writableStreamAbort(stream, reason) {
  const {