How to create a session?

Question

Node.js

const express = require('express'),
    app = express(),
    port = 3000,
    clientSessions = require('client-sessions');

app.use(clientSessions({
    secret: '0GBlJZ9EKBt2Zbi2flRPvztczCewBxXK' // set this to a long random string!
}));

app.get('/',(request,response) => {
    request.session.username = 'qwer';
});

app.get('/1',(request,response) => {
    console.log(request.session.username);
});

app.listen(port,(err) => {
    if(err){
        return console.log(err);
    }

    console.log(`Слушается порт ${port}`);
});

Writes an error

TypeError: Cannot set property 'username' of undefined
at W:\domains\auth\index.js:11:30
at Layer.handle [as handle_request] (W:\domains\auth\node_modules\express\lib\router\layer .js:95:5)
at next (W:\domains\auth\node_modules\express\lib\router\route.js:137:13)
at Route.dispatch (W:\domains\auth\node_modules\express\lib \router\route.js:112:3)
at Layer.handle [as handle_request] (W:\domains\auth\node_modules\express\lib\router\layer.js:95:5)
at W:\domains\auth \node_modules\express\lib\router\index.js:281:22
at Function.process_params (W:\domains\auth\node_modules\express\lib\router\index.js:335:12)
at next (W:\ domains\auth\node_modules\express\lib\router\index.js:275:10)
at clientSession (W:\domains\auth\node_modules\client-sessions\lib\client-sessions.js:630:5)
at Layer.handle [as handle_request] (W:\domains\auth\node_modules\express\lib\ router\layer.js:95:5)

What is the problem? Why doesn't it define

Answer 1

as shown in the description of client-sessions, in addition to the secret option, you need to set a number of options, such as cookieName (aka the session name) or requestKey (requestKey overrides cookieName for the key name added to the request object).
which will allow you to access the session through req

your example with bug fixes

const express = require('express'),
    app = express(),
    port = 3000,
    clientSessions = require('client-sessions');

app.use(clientSessions({
    secret: '0GBlJZ9EKBt2Zbi2flRPvztczCewBxXK', // set this to a long random string!
    cookieName: 'ss', // cookie name dictates the key name added to the request object
    requestKey: 'session', // requestKey overrides cookieName for the key name added to the request object.
}));

app.get('/',(request,response,next) => {
    request.session.username = 'qwer';
    response.send("вы обратились к /");
});

app.get('/1',(request,response,next) => {
    console.log(request.session.username);
    response.send("вы обратились к /1<br>в сессии сохранено: "+JSON.stringify(request.session));
});

app.listen(port,(err) => {
    if(err){
        return console.log(err);
    }

    console.log(`Слушается порт ${port}`);
});

PS: and don't forget to call next(); where it is required to transfer control to the next handler or request.end() or request.send(...) where it is required to stop further processing of the request
PSPS: and please write where you had problems with the previously proposed solution or mark it as solved .