Swift 6 updates (pointfreeco#3379)

* Swift 6 updates

  - Soft-deprecate `_SynthesizedConformance` now that Xcode 16 has fixed
    this bug.
    - Update docs accordingly.

  - Document Xcode 16 macro gotcha around custom build configuration
    names.

* wip

Author: stephencelis

.github/workflows/ci.yml

@@ -82,11 +82,11 @@ jobs:
             deriveddata-examples-${{ hashFiles('**/Sources/**/*.swift', '**/Tests/**/*.swift', '**/Examples/**/*.swift') }}
           restore-keys: |
             deriveddata-examples-
-      - name: Select Xcode 15.4
-        run: sudo xcode-select -s /Applications/Xcode_15.4.app
-      - name: Set IgnoreFileSystemDeviceInodeChanges flag 
+      - name: Select Xcode 16
+        run: sudo xcode-select -s /Applications/Xcode_16_beta_6.app
+      - name: Set IgnoreFileSystemDeviceInodeChanges flag
         run: defaults write com.apple.dt.XCBuild IgnoreFileSystemDeviceInodeChanges -bool YES
-      - name: Update mtime for incremental builds 
+      - name: Update mtime for incremental builds
         uses: chetan/git-restore-mtime-action@v2
       - name: CaseStudies (SwiftUI)
         run: make SCHEME="CaseStudies (SwiftUI)" test-example

Examples/CaseStudies/SwiftUICaseStudies/04-Navigation-Multiple-Destinations.swift

@@ -8,7 +8,7 @@ private let readMe = """
 
 @Reducer
 struct MultipleDestinations {
-  @Reducer(state: .equatable)
+  @Reducer
   enum Destination {
     case drillDown(Counter)
     case popover(Counter)
@@ -46,6 +46,7 @@ struct MultipleDestinations {
     .ifLet(\.$destination, action: \.destination)
   }
 }
+extension MultipleDestinations.Destination.State: Equatable {}
 
 struct MultipleDestinationsView: View {
   @Bindable var store: StoreOf<MultipleDestinations>

Examples/CaseStudies/SwiftUICaseStudies/04-NavigationStack.swift

@@ -7,7 +7,7 @@ private let readMe = """
 
 @Reducer
 struct NavigationDemo {
-  @Reducer(state: .equatable)
+  @Reducer
   enum Path {
     case screenA(ScreenA)
     case screenB(ScreenB)
@@ -65,6 +65,7 @@ struct NavigationDemo {
     .forEach(\.path, action: \.path)
   }
 }
+extension NavigationDemo.Path.State: Equatable {}
 
 struct NavigationDemoView: View {
   @Bindable var store: StoreOf<NavigationDemo>

Examples/Integration/Integration/Legacy/LegacyPresentationTestCase.swift

@@ -9,7 +9,7 @@ private enum PresentationTestCase {
       var message = ""
       @PresentationState var destination: Destination.State?
     }
-    enum Action: Equatable, Sendable {
+    enum Action: Sendable {
       case alertButtonTapped
       case customAlertButtonTapped
       case destination(PresentationAction<Destination.Action>)
@@ -21,7 +21,7 @@ private enum PresentationTestCase {
       case sheetButtonTapped
     }
 
-    @Reducer(state: .equatable, action: .equatable)
+    @Reducer
     enum Destination {
       case alert(AlertState<AlertAction>)
       case customAlert
@@ -312,8 +312,8 @@ private enum PresentationTestCase {
       }
     }
   }
-
 }
+extension PresentationTestCase.Feature.Destination.State: Equatable {}
 
 struct PresentationTestCaseView: View {
   private let store: StoreOf<PresentationTestCase.Feature>

Examples/Integration/Integration/iOS 17/ObservableEnumTestCase.swift

@@ -66,7 +66,7 @@ struct ObservableEnumView: View {
 
   @Reducer
   struct Feature {
-    @Reducer(state: .equatable)
+    @Reducer
     enum Destination {
       case feature1(ObservableBasicsView.Feature)
       case feature2(ObservableBasicsView.Feature)
@@ -111,6 +111,7 @@ struct ObservableEnumView: View {
     }
   }
 }
+extension ObservableEnumView.Feature.Destination.State: Equatable {}
 
 #Preview {
   Logger.shared.isEnabled = true

Examples/Integration/Integration/iOS 17/ObservablePresentationTestCase.swift

@@ -94,7 +94,7 @@ struct ObservablePresentationView: View {
 
   @Reducer
   struct Feature {
-    @Reducer(state: .equatable)
+    @Reducer
     enum Destination {
       case fullScreenCover(ObservableBasicsView.Feature)
       case popover(ObservableBasicsView.Feature)
@@ -146,3 +146,4 @@ struct ObservablePresentationView: View {
     }
   }
 }
+extension ObservablePresentationView.Feature.Destination.State: Equatable {}

Examples/SyncUps/SyncUps/AppFeature.swift

@@ -3,7 +3,7 @@ import SwiftUI
 
 @Reducer
 struct AppFeature {
-  @Reducer(state: .equatable)
+  @Reducer
   enum Path {
     case detail(SyncUpDetail)
     case meeting(Meeting, syncUp: SyncUp)
@@ -47,6 +47,7 @@ struct AppFeature {
     .forEach(\.path, action: \.path)
   }
 }
+extension AppFeature.Path.State: Equatable {}
 
 struct AppView: View {
   @Bindable var store: StoreOf<AppFeature>

Examples/SyncUps/SyncUps/SyncUpDetail.swift

@@ -3,7 +3,7 @@ import SwiftUI
 
 @Reducer
 struct SyncUpDetail {
-  @Reducer(state: .equatable)
+  @Reducer
   enum Destination {
     case alert(AlertState<Alert>)
     case edit(SyncUpForm)
@@ -109,6 +109,7 @@ struct SyncUpDetail {
     .ifLet(\.$destination, action: \.destination)
   }
 }
+extension SyncUpDetail.Destination.State: Equatable {}
 
 struct SyncUpDetailView: View {
   @Bindable var store: StoreOf<SyncUpDetail>

Examples/SyncUps/SyncUps/SyncUpsList.swift

@@ -3,7 +3,7 @@ import SwiftUI
 
 @Reducer
 struct SyncUpsList {
-  @Reducer(state: .equatable)
+  @Reducer
   enum Destination {
     case add(SyncUpForm)
     case alert(AlertState<Alert>)
@@ -73,6 +73,7 @@ struct SyncUpsList {
     .ifLet(\.$destination, action: \.destination)
   }
 }
+extension SyncUpsList.Destination.State: Equatable {}
 
 struct SyncUpsListView: View {
   @Bindable var store: StoreOf<SyncUpsList>

Examples/TicTacToe/tic-tac-toe/Sources/AppCore/AppCore.swift

@@ -2,7 +2,7 @@ import ComposableArchitecture
 import LoginCore
 import NewGameCore
 
-@Reducer(state: .equatable)
+@Reducer
 public enum TicTacToe {
   case login(Login)
   case newGame(NewGame)
@@ -37,3 +37,4 @@ public enum TicTacToe {
     }
   }
 }
+extension TicTacToe.State: Equatable {}