Method Then

napi-inl.h:2989–3010

inline Promise::Promise(napi_env env, napi_value value) : Object(env, value) {}

inline MaybeOrValue<Promise> Promise::Then(napi_value onFulfilled) const {
  EscapableHandleScope scope(_env);
#ifdef NODE_ADDON_API_ENABLE_MAYBE
  Value thenMethod;
  if (!Get("then").UnwrapTo(&thenMethod)) {
    return Nothing<Promise>();
  }
  MaybeOrValue<Value> result =
      thenMethod.As<Function>().Call(*this, {onFulfilled});
  if (result.IsJust()) {
    return Just(scope.Escape(result.Unwrap()).As<Promise>());
  }
  return Nothing<Promise>();
#else
  Function thenMethod = Get("then").As<Function>();
  MaybeOrValue<Value> result = thenMethod.Call(*this, {onFulfilled});
  if (scope.Env().IsExceptionPending()) {
    return Promise();
  }
  return scope.Escape(result).As<Promise>();
#endif
}

inline MaybeOrValue<Promise> Promise::Then(napi_value onFulfilled,
                                           napi_value onRejected) const {