Swift 6 compatibility

[Supereg]

Swift 6 compatibility

♻️ Current situation & Problem

This PR fixes the swift concurrency flag. There weren't any concurrency warnings left when compiling with the latest Swift 6 toolchain that is part of Xcode 16 beta 3. Note, that Xcode 15 will trigger some warnings as some symbols aren't annotated as Sendable in the previous SDK. Further, some sendability checks changed.

This PR changes some actor isolations of some types and interfaces. Most importantly, we add @MainActor isolation to the Module/configure() method. We found, that a lot of modules manipulate @MainActor isolated properties in their configure method (those that are relevant for UI components) but cannot do so without spawning a new Task, as the configure method previously didn't have @MainActor guarantees. Except for out-of-band module loading, configure() would have always been called on the Main Actor (through SwiftUI initialization). Making all module interactions to be isolated to @MainActor greatly simplifies some of our internal state handling.

⚙️ Release Notes

• Fix swift strict concurrency flag.
• Resolve some strict concurrency warnings.

Breaking Changes

• Module/configure() is now isolated to @MainActor.
• Spezi/loadModule(_:ownership:) and Spezi/unloadModule(_:) are now isolated to @MainActor.

📚 Documentation

Minor documentation files.

✅ Testing

Test target was updated to latest concurrency changes as well.

📝 Code of Conduct & Contributing Guidelines

By submitting creating this pull request, you agree to follow our Code of Conduct and Contributing Guidelines:

• I agree to follow the Code of Conduct and Contributing Guidelines.

[PSchmiedmayer]

Thank you for looking into this @Supereg!

[Supereg]

@PSchmiedmayer the Xcode 15 toolchain still triggers some concurrency warnings that are not triggered with the Xcode 16 beta 3 toolchain (e.g., Logger has now Sendable conformance with the latest SDKs). Should we aim to host some Xcode 16 runners soon? This could also be useful to enable Swift 6 language mode in which Concurrency warnings are treated as errors which would make efforts in StanfordSpezi/.github#50 to be non-essential.

We could either move with all runners to the beta toolchain for the Spezi Org. Seems relatively stable by now and is probably the easiest to maintain. Otherwise, we could allocate some dedicated Swift 6 runners if we have the capacity.

Let me know what you think.

[codecov]

Codecov Report

Attention: Patch coverage is 95.69892% with 4 lines in your changes missing coverage. Please review.

Project coverage is 85.85%. Comparing base (5ada3f3) to head (d71107c).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #108      +/-   ##
==========================================
- Coverage   87.64%   85.85%   -1.78%     
==========================================
  Files          46       45       -1     
  Lines        1375     1392      +17     
==========================================
- Hits         1205     1195      -10     
- Misses        170      197      +27     

Files	Coverage Δ
...ilities/Communication/ProvidePropertyWrapper.swift	100.00% <100.00%> (ø)
...bilities/Communication/StorageValueCollector.swift	100.00% <ø> (ø)
...abilities/Communication/StorageValueProvider.swift	100.00% <ø> (ø)
...pezi/Capabilities/Lifecycle/LifecycleHandler.swift	88.89% <ø> (ø)
...ifications/RegisterRemoteNotificationsAction.swift	85.11% <ø> (ø)
...apabilities/Observable/EnvironmentAccessible.swift	100.00% <100.00%> (ø)
...Capabilities/Observable/ModelPropertyWrapper.swift	69.77% <100.00%> (+3.11%)	⬆️
...ilities/ViewModifier/ModifierPropertyWrapper.swift	80.00% <100.00%> (+2.23%)	⬆️
...pabilities/ViewModifier/ViewModifierProvider.swift	94.45% <100.00%> (ø)
Sources/Spezi/Dependencies/DependencyManager.swift	78.45% <ø> (-19.82%)	⬇️
... and 15 more

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[PSchmiedmayer]

Thank you for all the improvements to get the package Swift 6-ready.

I have also installed Xcode 16.0 Beta 3 on our runners so we check that with the latest encode version and validate that the package builds with Xcode 16 and Swift 6.

One thing I noticed. Out of curiosity I tried to update the Swift tools version in the Package.swift to 6.0 but got multiple compiler errors without any direct references to source code errors. I am not sure if you can verify this on your machine or if this is a general issue that might be related to the Xcode beta?

Would be great if we bump the tools version to 6.0 after Swift 6 is released.