`User.empty` - why not nil?

[tomholub]

I've never liked this User.empty usage. Why not nil? Let's discuss in another issue.

Originally posted by @tomholub in #1030 (comment)

[tomholub]

[ivan-ushakov]

We use empty for something like default/initial values. We could rename it, but leave as it is because we need such object for our form screens.

[tomholub]

What is a form screen - could you show example?

[ivan-ushakov]

What is a form screen - could you show example?

SetupImapViewController. I used form screen for any screen with fields user have to fill in.

[tomholub]

Couldn't we have a nil user instead of empty user?

Maybe it's a common pattern on iOS to have "empty values" but I find it to be an anti-pattern. Because User? is explicit - I need to check for emptiness. But User - how would I ever know to check? Unless I'm familiar with the codebase to know it may be an .empty user.

[ivan-ushakov]

Because we need to store data entered by user somewhere. So we need to have empty User model.

[tomholub]

I see. That sounds even worse :-) Do we really need to store that data? Can't we keep it in memory until we are ready to save a real user?

[ivan-ushakov]

I see. That sounds even worse :-) Do we really need to store that data? Can't we keep it in memory until we are ready to save a real user?

Let's try this approach.

[tomholub]

If this only applies to IMAP/SMTP setup, then those are possibly currently broken :-/ (during my async migration). But maybe it works enough to be able to set up the app. I think the broken part was token refresh / renew.

// edit - this should now be mostly fixed