Drop-in replacement for Express session using a cookie

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npm i -S @mrsimonemms/cookie-session

There is a fully-worked example in the example directory

import express from 'express';
import { CookieSession } from '@mrsimonemms/cookie-session';

const app = express();

app
  .use(
    CookieSession.express({
      flash: true, // This will delete the data once read
      secret: 'this-is-a-secret-signing-key', // Must be minimum of 16 characters
    }),
  )
  .get('/', (req, res) => {
    // If done using "flash", this will delete the "date" session, but not "date2"
    const { date } = req.session;

    res.json({ sessionId: req.sessionID, getter: { date } });
  })
  .get('/set', (req, res) => {
    const date = new Date();
    req.session.date = date;
    req.session.data2 = date;

    res.json({ setter: { date } });
  })
  .listen(3000, () => {
    console.log('Lisening');
  });

I was recently building an API for an application that used OIDC for managing its authentication. RESTful API should ALWAYS be build in a stateless manner. However, the OIDC workflow requires a session to link data between sending and verification.

Using a fully-blown Express Session wasn't necessary for my purposes - I didn't want to have to add a Redis backend to store the session data. The amount of data stored will always be under 4kb so a cookie is more than adequate.

I also wanted to have the concept of "flash" data - that is a piece of data that is immediately deleted once read. As my use-case is an API and exists purely as link data, enforcing flash sessions prevents the data from being relied upon by my application.

• Client sessions - this was my previous library, but it seems unmaintained (last release in 2014) and doesn't have flash data. Also, no TypeScript support
• Cookie-session - the official Express method of achieving this. As above, this doesn't have flash data.

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