TCA breaks source editor and autocomplete in Xcode 14

[tyler927]

I cannot seem to use TCA in Xcode 14 (I've tried beta 4 and 5), which is odd to me because the latest Point-Free videos seem to be using Xcode 14 just fine.

Once I import ComposableArchitecture into a file, pretty much everything I type seems to crash the editor and autocomplete showing the An internal error occurred. Source editor functionality is limited. Attempting to restore.. message.

I created a brand new SwiftUI iOS app in Xcode 14, add TCA as a dependency, make a new file, import TCA, and just typing struct crashes the editor. (This happens in my person apps, and the Case Studies project as well)

Things I've tried: Clean build, delete derived data, reboot, make project in Xcode 13 and then open in 14, none of these seem to help.

It does all work perfect in my Xcode 13.
I'm on a M1 Pro 16" with macOS 12.4.

Anyone else experiencing this, or have any ideas how to fix?

[mbrandonw]

Very strange, I'm not able to reproduce this:

Just to confirm, are you pulling in the latest release of TCA? 0.39.0? What happens if you try pulling in some older versions? Does it ever get more stable?

[mbrandonw]

@tgrapperon @tyler927 Thanks for bringing this to our attention and for doing so much research to help us track it down.

We think it's probably best to remove the typealias for now. Here's a PR with some discussion on why the typealias isn't even useful today. Once we merge and release that you should be able to update to get a more stable editor.

However, though we have removed it from combine-schedulers, we do have future need for this pattern in the protocol features that are coming soon. We hope we can elevate the bugs with Apple to see if there's a possibility to fix it before we are ready to fully release the protocol stuff. 😐

[tgrapperon]

In any case, I've managed to cook up this declaration that doesn't cause warnings:

public protocol SchedulerOf<S>: Scheduler {
  associatedtype S: Scheduler where S.SchedulerTimeType == SchedulerTimeType
}

as something that approximately bears the same function/signature as:

public typealias SchedulerOf<S: Scheduler> = Scheduler<S.SchedulerTimeType>

The constraint over the generic is stronger however, so I doubt it can be used everywhere the typealias was able to be.

[mbrandonw]

@tgrapperon Interesting, thanks for investigating the alternatives.

We just released 0.7.2 of combine schedulers which should fix the editor stability problems.

[tyler927]

Wow nice work tracking that down and getting a fix out for now @mbrandonw @tgrapperon , hopefully Apple can get that root issue actually fixed soon. I can confirm that 0.7.2 of combine schedulers has fixed my issues in beta 5 👍

[tgrapperon]

Confirmed fixed in Xcode 14.1!
swiftlang/swift#60801
swiftlang/swift#60550