processPromiseRejections.js

function processPromiseRejections() {
  ...
  ...

  let len = pendingUnhandledRejections.length;
  while (len--) {
    const promise = ArrayPrototypeShift(pendingUnhandledRejections);
    const promiseInfo = maybeUnhandledPromises.get(promise);
    if (promiseInfo === undefined) {
      continue;
    }
    ...
    const { reason, uid, emit } = promiseInfo;
    
    switch (unhandledRejectionsMode) {
      case kStrictUnhandledRejections: { ... }
      case kIgnoreUnhandledRejections: {
        emit(reason, promise, promiseInfo);
        break;
      }
      case kThrowUnhandledRejections: { ... }
      case kWarnWithErrorCodeUnhandledRejections: { ... }

    ...
    ...
  }
}