Next.js cookie-session example

hello.js

// pages/api/hello.js

import CookieSession from 'cookie-session'
const cookieSession = CookieSession({ name: 'session', keys: ['foo', 'bar'] })

function runMiddleware(req, res, fn) {
  return new Promise((resolve, reject) => {
    fn(req, res, result => {
      if (result instanceof Error) {
        return reject(result)
      }
      return resolve(result)
    })
  })
}

async function handler(req, res) {
  await runMiddleware(req, res, cookieSession)
  req.session.count = (req.session.count || 0) + 1

  console.log(req.session.count)
  res.statusCode = 200
  res.json({ name: 'John Doe', count: req.session.count })
}

export default handler