session.server.ts

import { createCookieSessionStorage } from 'react-router'

export const authSessionStorage = createCookieSessionStorage({
	cookie: {
		name: 'en_session',
		sameSite: 'lax', // CSRF protection is advised if changing to 'none'
		path: '/',
		httpOnly: true,
		secrets: process.env.SESSION_SECRET.split(','),
		secure: process.env.NODE_ENV === 'production',
	},
})

// we have to do this because every time you commit the session you overwrite it
// so we store the expiration time in the cookie and reset it every time we commit
const originalCommitSession = authSessionStorage.commitSession

Object.defineProperty(authSessionStorage, 'commitSession', {
	value: async function commitSession(
		...args: Parameters<typeof originalCommitSession>
	) {
		const [session, options] = args
		if (options?.expires) {
			session.set('expires', options.expires)
		}
		if (options?.maxAge) {
			session.set('expires', new Date(Date.now() + options.maxAge * 1000))
		}
		const expires = session.has('expires')
			? new Date(session.get('expires'))
			: undefined
		const setCookieHeader = await originalCommitSession(session, {
			...options,
			expires,
		})
		return setCookieHeader
	},
})