Unify inconsistent api for manipulating session

[lokshunhung]

Prerequisites

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🚀 Feature Proposal

Originally proposed by @SimenB, as quoted

[Add] methods on the session object itself rather than directly on the request object - today it has only regenerate and touch, but not save etc.. When using Express' session I never interacted with sessionStore directly, all methods (save, regenerate, reload, destroy) were all on the session object.

express fastify
request.session.reload(cb) request.sessionStore.get(request.session.sessionId, cb)
request.session.save({}, cb) request.sessionStore.set(request.session.sessionId, {}, cb)
request.session.regenerate(cb) request.session.regenerate() (no callback in fastify, unlike express)
request.session.destroy(cb) request.destroySession(cb)
request.session.touch() request.session.touch()
the methods for express also updates request.session - I guess calling the store directly doesn't do the same (that's probably a bug in my current migration at work).

If all methods are moved to request.session then I guess you can also choose not to expose sessionStore at all?

Motivation

The api to interact with session is very inconsistent.

Context here

Example

Instead of

request.sessionStore.get(request.session.sessionId, cb)
request.destroySession(cb)

We could do

await request.session.reload()
await request.session.destroy()