Swift 6 beta compiler crash while using teststore.receive for Void results

[Alex293]

Hi,

The Swift 6 compiler from the first Xcode 16 beta (in 5.10 mode) crashes when using testStore.receive method that takes a CaseKeyPath toward a result with Void success Value.

This was working before :

case saveAnswersResponse(Result<Void, Error>)

await store.receive(\.saveAnswersResponse.success) {
  $0.isSaveAnswerRequestInFlight = false
}

I made it work again using a Unit type :

public struct Unit: Equatable { public init() {} }
case saveAnswersResponse(Result<Unit, Error>)

await store.receive(\.saveAnswersResponse.success, .init()) {
  $0.isSaveAnswerRequestInFlight = false
}

but this is far from perfect.

Now this isn't a bug in TCA per se but I think it will be quite a common issue. Has anyone encountered this issue and have a better fix ? I'll work on a reproducer and open a bug report and will update this issue when done.

[Alex293]

Duplicate for pointfreeco/swift-case-paths#167