When authenticating via endpoint/user/login the user object or uid should be returned

Re #9: The information is correct, but at least since #2238561: Use the default PHP session ID instead of generating a custom one → (Change record: https://www.drupal.org/node/3006306 → )
the

'id' => $this->session->getId(),

returns an empty string!

So using the services module login method returns:

{
  "id": "",
  "name": "SSESS2a2e46d6add4bddd473123417e13ddc0067a6f"
}

Adding

$this->session->save();

prior to the return statement restores the expected functionality.

Still this isn't very helpful, I think?

Looking at the code one line below you see a maintainer comment:

// Return $this->entityManager->getStorage('user')->load($uid);

So I'm adding a MR not only to save the session and fix the empty ID, but also to return the user ID of the logged in user on success.

Could someone please review this approach?

I just compared this to the Drupal 7 result and I think we should try to get parity, where possible and useful.
Getting the user information on login is very typical I think to show user information. If someone disagrees, we should at least allow to fetch the user information easily in a second call: ✨ Add (current) user information ServiceDefinition Active

So best would be maintainer feedback here to hear, if adding user details to the response is fine or this should be split off!