req.session.user get undefined whenever i change anything on my server, and on the first i make a ca-CodePudding

my code works but whenever i made a change in the server.js, the req.session.user turns undefined.

This also happens the first time i make a request from the front, i do get authenticate. but right after i dont get the user.name and cookie cause it reads undefined.

if I run it again, it works and it keeps working until i quit the server and start again. it repeats the same pattern, doesnt work first time, then it works.

i believe is related to the backend as any change in the backend gets session.user undefined,

server.js

const express = require("express");
const session = require("express-session");
const app = express();
const mysql = require("mysql2/promise");

app.use(express.json());
    
app.use(
  session({
    key: "userId",
    secret: "password",
    resave: false,
    saveUninitialized: false,
    cookie: {
      expires: 1000 * 60 * 60 * 24, 
    },
  })
);

app.use(
  cors({
    credentials: true,
    origin: ["http://localhost:3000"],
    methods: ["GET", "POST"],
  })
);
app.post("/login", async (req, res) => {
  const { userName, password } = req.body;
  

  try {
    const [result] = await db.query(
      `select * from user 
        where 
        user = ? and
        password = ? `,
      [userName, password]
    );

    if (result.length > 0) {
      req.session.user = {
        loggedIn: true,
        user_id: result[0].user_id,
        name: result[0].name,
      };
      res.send(req.session.user);
    } else {
      res.send({ message: "Wrong password or user" });
    }
  } catch (error) {
    console.error(error);
  }
});

// checking whats on the session
app.use((req, res, next) => {
  console.log(req.session.user);
  next();
});

// session retriving
app.get("/login", (req, res) => {
  req.session.user
    ? res.send({
        loggedIn: true,
        name: req.session.user.name,
        user_id: req.session.user.user_id,
      })
    : res.send({ loggedIn: false });
});

app.js

Axios.defaults.withCredentials = true;
useEffect(() => {
    
    Axios.get("http://localhost:3001/login").then(({ data }) => {
      setUser({
        loggedIn: data.loggedIn,
        name: data.name,
        user_id: data.user_id,
      });
      console.log(data);
    });
  }, []);

CodePudding user response：

Whenever you change server.js - your server gets restarted, and since you don't have a session store where your session is saved the session is lost everytime the server is restarted. (the session is kept only in memory)

When you check out session readme, https://github.com/expressjs/session it says:

Warning The default server-side session storage, MemoryStore, is purposely not designed for a production environment. It will leak memory under most conditions, does not scale past a single process, and is meant for debugging and developing. For a list of stores, see compatible session stores.

So check out: https://github.com/expressjs/session#compatible-session-stores to find a store that might suit you.

CodePudding user response：

Since session are stored on memory it will reset everytime your backend got restarted. If you don't want that you can create one static session/token to use on DEVELOPMENT ONLY.