deps/v8/src/js/promise.js
function RejectPromise(promise, reason) {
  // Check promise status to confirm that this reject has an effect.
  // Call runtime for callbacks to the debugger or for unhandled reject.
  if (GET_PRIVATE(promise, promiseStateSymbol) === kPending) {
    var debug_is_active = DEBUG_IS_ACTIVE;
    if (debug_is_active ||
        !HAS_DEFINED_PRIVATE(promise, promiseHasHandlerSymbol)) {
      %PromiseRejectEvent(promise, reason, debug_is_active);
    }
  }
  FulfillPromise(promise, kRejected, reason, promiseRejectReactionsSymbol)
}
function RejectPromise(promise, reason) {
  // Check promise status to confirm that this reject has an effect.
  // Call runtime for callbacks to the debugger or for unhandled reject.
  if (GET_PRIVATE(promise, promiseStateSymbol) === kPending) {
    var debug_is_active = DEBUG_IS_ACTIVE;
    if (debug_is_active ||
        !HAS_DEFINED_PRIVATE(promise, promiseHasHandlerSymbol)) {
      %PromiseRejectEvent(promise, reason, debug_is_active);
    }
  }
  FulfillPromise(promise, kRejected, reason, promiseRejectReactionsSymbol)
}
ES#sec-rejectpromise RejectPromise ( promise, reason )