Express session

var app = express();
var session = require("express-session");

app.set("trust proxy", 1); // trust first proxy
app.use(
  session({
    secret: "keyboard cat",
    resave: false,
    saveUninitialized: true,
    cookie: { secure: true }
  })
);

Max age

• https://www.npmjs.com/package/express-session#cookiemaxage

after 1000ms, session will be deleted.

  cookie: { secure: true, maxAge: 1000 }

Error Handling

Promise.resolve()
  .then(() => {})
  .then(results => {
    // throw new Error('duplicate : userId'); // this way is for stack trace.(development)
    return Promise.reject("duplicate"); // this way is for business logic(notify to client)
  })
  .catch(err => {
    if (err === "duplicate") return jsonSender.sendDuplicate(res, "duplicate");
    next(err);
  });

Compare code

Promise.resolve()
    .then(() => {
      // Find userId already exists.
      const promises = [];
      const query = { userId: doc.userId };
      promises.push(StagingUser.findOne(query));
      promises.push(User.findOne(query));
      return Promise.all(promises);
    })
    .then((results) => {
      if (!(results[0] === null && results[1] === null)) return Promise.reject({ localError: true, localErrorMsg: 'DUPLICATE_USER_ID' });
      return;
    })
    .then(() => {
      // Find mobile number already exists.
      const promises = [];
      const query = { mobileNumber: doc.mobileNumber };
      promises.push(StagingUser.findOne(query));
      promises.push(User.findOne(query));
      return Promise.all(promises);
    })
    .then((results) => {
      if (!(results[0] === null && results[1] === null)) return Promise.reject({ localError: true, localErrorMsg: 'DUPLICATE_MOBILE_NUMBER' });
      return;
    })
    .then(() => {
      const stagingUser = new StagingUser(doc);
      return stagingUser.save();
    })
    .then((dbRes) => {
      jsonSender.sendSuccess(res, 'Staging user signup success');
    })
    .catch((err) => {
      if (err.localError) return jsonSender.sendDuplicate(res, err.localErrorMsg);
      next(err);
    });
};

Promise.resolve()
    .then(() => {
      // Find userId already exists.
      const promises = [];
      const query = { userId: doc.userId };
      promises.push(StagingUser.findOne(query));
      promises.push(User.findOne(query));
      return Promise.all(promises).then((results) => {
        if (!(results[0] === null && results[1] === null)) return Promise.reject({ localError: true, localErrorMsg: 'DUPLICATE_USER_ID' });
        return;
      });
    })
    .then(() => {
      // Find mobile number already exists.
      const promises = [];
      const query = { mobileNumber: doc.mobileNumber };
      promises.push(StagingUser.findOne(query));
      promises.push(User.findOne(query));
      return Promise.all(promises).then((results) => {
        if (!(results[0] === null && results[1] === null)) return Promise.reject({ localError: true, localErrorMsg: 'DUPLICATE_MOBILE_NUMBER' });
        return;
      });
    })
    .then(() => {
      const stagingUser = new StagingUser(doc);
      return stagingUser.save();
    })
    .then((dbRes) => {
      jsonSender.sendSuccess(res, 'Staging user signup success');
    })
    .catch((err) => {
      if (err.localError) return jsonSender.sendDuplicate(res, err.localErrorMsg);
      next(err);
    });
};