пн goose (проверить и сохранить, если новый)

Question

Я получаю эту ошибку, и запрос должен быть выполнен только один раз,

 UnhandledPromiseRejectionWarning: ParallelSaveError: Can't save() the same doc multiple times in parallel. Document: 5e269bd87c588b6285499c14
    at ParallelSaveError.MongooseError [as constructor] (/root/react-passport-example/node_modules/mongoose/lib/error/mongooseError.js:10:11)
    at new ParallelSaveError (/root/react-passport-example/node_modules/mongoose/lib/error/parallelSave.js:18:17)
    at model.Model.save (/root/react-passport-example/node_modules/mongoose/lib/model.js:434:20)
    at /root/react-passport-example/server/routes/public_api.js:64:21
    at /root/react-passport-example/node_modules/mongoose/lib/model.js:4590:16
    at /root/react-passport-example/node_modules/mongoose/lib/query.js:4351:12
    at cb (/root/react-passport-example/node_modules/mongoose/lib/query.js:1900:14)
    at result (/root/react-passport-example/node_modules/mongodb/lib/operations/execute_operation.js:75:17)    at executeCallback (/root/react-passport-example/node_modules/mongodb/lib/operations/execute_operation.js:68:9)
    at handleCallback (/root/react-passport-example/node_modules/mongodb/lib/utils.js:129:55)
    at cursor.close (/root/react-passport-example/node_modules/mongodb/lib/operations/to_array.js:36:13)       at handleCallback (/root/react-passport-example/node_modules/mongodb/lib/utils.js:129:55)
    at completeClose (/root/react-passport-example/node_modules/mongodb/lib/cursor.js:859:16)
    at Cursor.close (/root/react-passport-example/node_modules/mongodb/lib/cursor.js:878:12)
    at cursor._next (/root/react-passport-example/node_modules/mongodb/lib/operations/to_array.js:35:25)       at self._initializeCursor (/root/react-passport-example/node_modules/mongodb/lib/core/cursor.js:750:9) (node:25221) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:25221) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Мне интересно, есть ли лучший и более чистый способ сделать следующее.

 router.post('/login', (req, res) => {
        var query = req.body,
        add = new LoginModel(query);
        console.log(query.email);

        LoginModel.find({uid : req.body.uid}, function (err, docs) {
            if (docs.length){
                console.log(err);
                res.status(200).json({
                    message: "ERROR USER ALREADY EXISIT",
                    // user values passed through from auth middleware
                    //user: req.user
                  });
            }else{
                add.save(add.save(function (err, query) {
                    if (err) return console.error(err);
                }));
            }
        });

   });

Answer 1

Это происходит потому, что вы дважды используете add.save в своем коде. Надеюсь, приведенный ниже код работает для вас.

 add.save((err, query) => {
    if (err) {
        return err;
    } else {
        return result;
    }
 });