add unit test for maxAge

[Uzlopak]

@rclmenezes

Why does it pass? :D

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[rclmenezes]

Is this a surprising result for you?

Because of this:
https://github.com/fastify/session/blob/master/lib/session.js#L44

[Uzlopak]

Well, in #121 you removed the .touch() call in the Session.constructor.

So the underlying bug is fixed properly?

Do we need to put the touch below the hash call?

[rclmenezes]

In the very first PR I noticed a bug where if saveUninitialized is false but maxAge is on, the cookie doesn't get reset:
https://github.com/fastify/session/pull/114/files#r942965564

Here's the test that replicates it:

test('should set session cookie if saveUninitialized is false and maxAge is on', async (t) => {
  t.plan(2)
  const options = {
    cookie: {
      maxAge: 42
    },
    secret: 'cNaoPYAwF60HZJzkcNaoPYAwF60HZJzk',
    saveUninitialized: false
  }
  const plugin = fastifyPlugin(async (fastify, opts) => {
    fastify.addHook('onRequest', (request, reply, done) => {
      request.sessionStore.set(DEFAULT_SESSION_ID, {
        // In this scenario, maxAge would have set expires in a previous request
        cookie: {
          expires: new Date(Date.now() + 1000)
        }
      }, done)
    })
  })
  const fastify = await buildFastify((request, reply) => reply.send(200), options, plugin)
  t.teardown(() => fastify.close())

  const response = await fastify.inject({
    url: '/',
    headers: { cookie: DEFAULT_COOKIE, 'x-forwarded-proto': 'https' }
  })

  t.equal(response.statusCode, 200)
  t.ok(response.headers['set-cookie'])
})

Changing the hash function fixes it:
https://github.com/fastify/session/pull/114/files#diff-1f2570998a9bf80486f544bb34c3bbf16e1af1755a37ac836eabbd82c6be4fb4R152-R153

if (this === sess && key === 'cookie') {
        // we want `touch` to affect the hash of the session
        return sess.cookie.expires?.getTime()
      }
}

[Uzlopak]

Can you provide a separate PR for your suggestion, please?

[rclmenezes]

Can you provide a separate PR for your suggestion, please?

Will do!