Existential any to protocol for Swift 6 (#3370)

* Apply existential any to protocol for Swift 6

* Update Package@swift-6.0.swift

* Update Package.swift

* Apply any to Macro.Type

* Apply any for the rest

* Applying the any keyword internally for typealias in a _KeyPath

* Undoing accidental syntax

---------

Co-authored-by: Stephen Celis <stephen@stephencelis.com>
Co-authored-by: Stephen Celis <stephen.celis@gmail.com>

Examples/CaseStudies/SwiftUICaseStudies/02-SharedState-Notifications.swift

@@ -24,7 +24,7 @@ struct SharedStateNotifications {
     @SharedReader(.screenshotCount) var screenshotCount = 0
   }
   enum Action {
-    case factResponse(Result<String, Error>)
+    case factResponse(Result<String, any Error>)
     case onAppear
   }
   @Dependency(\.factClient) var factClient

Examples/CaseStudies/SwiftUICaseStudies/03-Effects-Basics.swift

@@ -32,7 +32,7 @@ struct EffectsBasics {
     case decrementDelayResponse
     case incrementButtonTapped
     case numberFactButtonTapped
-    case numberFactResponse(Result<String, Error>)
+    case numberFactResponse(Result<String, any Error>)
   }
 
   @Dependency(\.continuousClock) var clock

Examples/CaseStudies/SwiftUICaseStudies/03-Effects-Cancellation.swift

@@ -25,7 +25,7 @@ struct EffectsCancellation {
     case cancelButtonTapped
     case stepperChanged(Int)
     case factButtonTapped
-    case factResponse(Result<String, Error>)
+    case factResponse(Result<String, any Error>)
   }
 
   @Dependency(\.factClient) var factClient

Examples/CaseStudies/SwiftUICaseStudies/03-Effects-Refreshable.swift

@@ -23,7 +23,7 @@ struct Refreshable {
   enum Action {
     case cancelButtonTapped
     case decrementButtonTapped
-    case factResponse(Result<String, Error>)
+    case factResponse(Result<String, any Error>)
     case incrementButtonTapped
     case refresh
   }

Examples/CaseStudies/SwiftUICaseStudies/03-Effects-WebSocket.swift

@@ -29,7 +29,7 @@ struct WebSocket {
     case alert(PresentationAction<Alert>)
     case connectButtonTapped
     case messageToSendChanged(String)
-    case receivedSocketMessage(Result<WebSocketClient.Message, Error>)
+    case receivedSocketMessage(Result<WebSocketClient.Message, any Error>)
     case sendButtonTapped
     case sendResponse(didSucceed: Bool)
     case webSocket(WebSocketClient.Action)
@@ -227,7 +227,7 @@ struct WebSocketClient {
   var open: @Sendable (_ id: ID, _ url: URL, _ protocols: [String]) async -> AsyncStream<Action> = {
     _, _, _ in .finished
   }
-  var receive: @Sendable (_ id: ID) async throws -> AsyncStream<Result<Message, Error>>
+  var receive: @Sendable (_ id: ID) async throws -> AsyncStream<Result<Message, any Error>>
   var send: @Sendable (_ id: ID, _ message: URLSessionWebSocketTask.Message) async throws -> Void
   var sendPing: @Sendable (_ id: ID) async throws -> Void
 }
@@ -295,7 +295,7 @@ extension WebSocketClient: DependencyKey {
         try self.socket(id: id).cancel(with: closeCode, reason: reason)
       }
 
-      func receive(id: ID) throws -> AsyncStream<Result<Message, Error>> {
+      func receive(id: ID) throws -> AsyncStream<Result<Message, any Error>> {
         let socket = try self.socket(id: id)
         return AsyncStream { continuation in
           let task = Task {

Examples/CaseStudies/SwiftUICaseStudies/04-NavigationStack.swift

@@ -190,7 +190,7 @@ struct ScreenA {
     case dismissButtonTapped
     case incrementButtonTapped
     case factButtonTapped
-    case factResponse(Result<String, Error>)
+    case factResponse(Result<String, any Error>)
   }
 
   @Dependency(\.dismiss) var dismiss

Examples/CaseStudies/SwiftUICaseStudies/05-HigherOrderReducers-ResuableOfflineDownloads/DownloadClient.swift

@@ -3,7 +3,7 @@ import Foundation
 
 @DependencyClient
 struct DownloadClient {
-  var download: @Sendable (_ url: URL) -> AsyncThrowingStream<Event, Error> = { _ in .finished() }
+  var download: @Sendable (_ url: URL) -> AsyncThrowingStream<Event, any Error> = { _ in .finished() }
 
   @CasePathable
   enum Event: Equatable {

Examples/CaseStudies/SwiftUICaseStudies/05-HigherOrderReducers-ResuableOfflineDownloads/DownloadComponent.swift

@@ -14,7 +14,7 @@ struct DownloadComponent {
   enum Action {
     case alert(PresentationAction<Alert>)
     case buttonTapped
-    case downloadClient(Result<DownloadClient.Event, Error>)
+    case downloadClient(Result<DownloadClient.Event, any Error>)
 
     @CasePathable
     enum Alert {

Examples/CaseStudies/SwiftUICaseStudies/05-HigherOrderReducers-ReusableFavoriting.swift

@@ -28,7 +28,7 @@ struct FavoritingState<ID: Hashable & Sendable>: Equatable {
 enum FavoritingAction {
   case alert(PresentationAction<Alert>)
   case buttonTapped
-  case response(Result<Bool, Error>)
+  case response(Result<Bool, any Error>)
 
   enum Alert: Equatable {}
 }

Examples/CaseStudies/SwiftUICaseStudiesTests/03-Effects-WebSocketTests.swift

@@ -6,7 +6,7 @@ import XCTest
 final class WebSocketTests: XCTestCase {
   func testWebSocketHappyPath() async {
     let actions = AsyncStream.makeStream(of: WebSocketClient.Action.self)
-    let messages = AsyncStream.makeStream(of: Result<WebSocketClient.Message, Error>.self)
+    let messages = AsyncStream.makeStream(of: Result<WebSocketClient.Message, any Error>.self)
 
     let store = await TestStore(initialState: WebSocket.State()) {
       WebSocket()
@@ -57,7 +57,7 @@ final class WebSocketTests: XCTestCase {
 
   func testWebSocketSendFailure() async {
     let actions = AsyncStream.makeStream(of: WebSocketClient.Action.self)
-    let messages = AsyncStream.makeStream(of: Result<WebSocketClient.Message, Error>.self)
+    let messages = AsyncStream.makeStream(of: Result<WebSocketClient.Message, any Error>.self)
 
     let store = await TestStore(initialState: WebSocket.State()) {
       WebSocket()

Examples/Search/Search/SearchView.swift

@@ -31,10 +31,10 @@ struct Search {
   }
 
   enum Action {
-    case forecastResponse(GeocodingSearch.Result.ID, Result<Forecast, Error>)
+    case forecastResponse(GeocodingSearch.Result.ID, Result<Forecast, any Error>)
     case searchQueryChanged(String)
     case searchQueryChangeDebounced
-    case searchResponse(Result<GeocodingSearch, Error>)
+    case searchResponse(Result<GeocodingSearch, any Error>)
     case searchResultTapped(GeocodingSearch.Result)
   }
 

Examples/SpeechRecognition/SpeechRecognition/SpeechClient/Live.swift

@@ -26,7 +26,7 @@ extension SpeechClient: DependencyKey {
 private actor Speech {
   var audioEngine: AVAudioEngine? = nil
   var recognitionTask: SFSpeechRecognitionTask? = nil
-  var recognitionContinuation: AsyncThrowingStream<SpeechRecognitionResult, Error>.Continuation?
+  var recognitionContinuation: AsyncThrowingStream<SpeechRecognitionResult, any Error>.Continuation?
 
   func finishTask() {
     self.audioEngine?.stop()
@@ -37,7 +37,7 @@ private actor Speech {
 
   func startTask(
     request: UncheckedSendable<SFSpeechAudioBufferRecognitionRequest>
-  ) -> AsyncThrowingStream<SpeechRecognitionResult, Error> {
+  ) -> AsyncThrowingStream<SpeechRecognitionResult, any Error> {
     let request = request.wrappedValue
 
     return AsyncThrowingStream { continuation in

Examples/SpeechRecognition/SpeechRecognition/SpeechRecognition.swift

@@ -20,7 +20,7 @@ struct SpeechRecognition {
   enum Action {
     case alert(PresentationAction<Alert>)
     case recordButtonTapped
-    case speech(Result<String, Error>)
+    case speech(Result<String, any Error>)
     case speechRecognizerAuthorizationStatusResponse(SFSpeechRecognizerAuthorizationStatus)
 
     enum Alert: Equatable {}

Examples/SyncUps/SyncUps/Dependencies/SpeechRecognizer.swift

@@ -137,11 +137,11 @@ private actor Speech {
   private var audioEngine: AVAudioEngine? = nil
   private var recognitionTask: SFSpeechRecognitionTask? = nil
   private var recognitionContinuation:
-    AsyncThrowingStream<SpeechRecognitionResult, Error>.Continuation?
+    AsyncThrowingStream<SpeechRecognitionResult, any Error>.Continuation?
 
   func startTask(
     request: SFSpeechAudioBufferRecognitionRequest
-  ) -> AsyncThrowingStream<SpeechRecognitionResult, Error> {
+  ) -> AsyncThrowingStream<SpeechRecognitionResult, any Error> {
     AsyncThrowingStream { continuation in
       self.recognitionContinuation = continuation
       let audioSession = AVAudioSession.sharedInstance()

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

@@ -19,7 +19,7 @@ public struct Login: Sendable {
 
   public enum Action: Sendable, ViewAction {
     case alert(PresentationAction<Alert>)
-    case loginResponse(Result<AuthenticationResponse, Error>)
+    case loginResponse(Result<AuthenticationResponse, any Error>)
     case twoFactor(PresentationAction<TwoFactor.Action>)
     case view(View)
 

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

@@ -20,7 +20,7 @@ public struct TwoFactor: Sendable {
 
   public enum Action: Sendable, ViewAction {
     case alert(PresentationAction<Alert>)
-    case twoFactorResponse(Result<AuthenticationResponse, Error>)
+    case twoFactorResponse(Result<AuthenticationResponse, any Error>)
     case view(View)
 
     public enum Alert: Equatable, Sendable {}

Examples/VoiceMemos/VoiceMemos/AudioPlayerClient/LiveAudioPlayerClient.swift

@@ -3,7 +3,7 @@ import Dependencies
 
 extension AudioPlayerClient: DependencyKey {
   static let liveValue = Self { url in
-    let stream = AsyncThrowingStream<Bool, Error> { continuation in
+    let stream = AsyncThrowingStream<Bool, any Error> { continuation in
       do {
         let delegate = try Delegate(
           url: url,
@@ -48,7 +48,7 @@ private final class Delegate: NSObject, AVAudioPlayerDelegate, Sendable {
     self.didFinishPlaying(flag)
   }
 
-  func audioPlayerDecodeErrorDidOccur(_ player: AVAudioPlayer, error: Error?) {
+  func audioPlayerDecodeErrorDidOccur(_ player: AVAudioPlayer, error: (any Error)?) {
     self.decodeErrorDidOccur(error)
   }
 }

Examples/VoiceMemos/VoiceMemos/AudioRecorderClient/LiveAudioRecorderClient.swift

@@ -37,7 +37,7 @@ private actor AudioRecorder {
   func start(url: URL) async throws -> Bool {
     self.stop()
 
-    let stream = AsyncThrowingStream<Bool, Error> { continuation in
+    let stream = AsyncThrowingStream<Bool, any Error> { continuation in
       do {
         self.delegate = Delegate(
           didFinishRecording: { flag in
@@ -83,11 +83,11 @@ private actor AudioRecorder {
 
 private final class Delegate: NSObject, AVAudioRecorderDelegate, Sendable {
   let didFinishRecording: @Sendable (Bool) -> Void
-  let encodeErrorDidOccur: @Sendable (Error?) -> Void
+  let encodeErrorDidOccur: @Sendable ((any Error)?) -> Void
 
   init(
     didFinishRecording: @escaping @Sendable (Bool) -> Void,
-    encodeErrorDidOccur: @escaping @Sendable (Error?) -> Void
+    encodeErrorDidOccur: @escaping @Sendable ((any Error)?) -> Void
   ) {
     self.didFinishRecording = didFinishRecording
     self.encodeErrorDidOccur = encodeErrorDidOccur
@@ -97,7 +97,7 @@ private final class Delegate: NSObject, AVAudioRecorderDelegate, Sendable {
     self.didFinishRecording(flag)
   }
 
-  func audioRecorderEncodeErrorDidOccur(_ recorder: AVAudioRecorder, error: Error?) {
+  func audioRecorderEncodeErrorDidOccur(_ recorder: AVAudioRecorder, error: (any Error)?) {
     self.encodeErrorDidOccur(error)
   }
 }

Examples/VoiceMemos/VoiceMemos/RecordingMemo.swift

@@ -17,7 +17,7 @@ struct RecordingMemo {
   }
 
   enum Action: Sendable {
-    case audioRecorderDidFinish(Result<Bool, Error>)
+    case audioRecorderDidFinish(Result<Bool, any Error>)
     case delegate(Delegate)
     case finalRecordingTime(TimeInterval)
     case onTask
@@ -26,7 +26,7 @@ struct RecordingMemo {
 
     @CasePathable
     enum Delegate: Sendable {
-      case didFinish(Result<State, Error>)
+      case didFinish(Result<State, any Error>)
     }
   }
 

Examples/VoiceMemos/VoiceMemos/VoiceMemo.swift

@@ -22,7 +22,7 @@ struct VoiceMemo {
   }
 
   enum Action {
-    case audioPlayerClient(Result<Bool, Error>)
+    case audioPlayerClient(Result<Bool, any Error>)
     case delegate(Delegate)
     case playButtonTapped
     case timerUpdated(TimeInterval)

Package.swift

@@ -91,6 +91,7 @@ let package = Package(
     target.swiftSettings = target.swiftSettings ?? []
     target.swiftSettings?.append(contentsOf: [
       .enableExperimentalFeature("StrictConcurrency"),
+      .enableUpcomingFeature("ExistentialAny"),
       .enableUpcomingFeature("InferSendableFromCaptures"),
     ])
   }

Package@swift-6.0.swift

@@ -87,8 +87,14 @@ let package = Package(
   swiftLanguageModes: [.v6]
 )
 
-for target in package.targets where target.type == .system || target.type == .test {
+for target in package.targets {
   target.swiftSettings = target.swiftSettings ?? []
+  target.swiftSettings?.append(contentsOf: [
+    .enableUpcomingFeature("ExistentialAny"),
+  ])
+}
+
+for target in package.targets where target.type == .system || target.type == .test {
   target.swiftSettings?.append(contentsOf: [
     .swiftLanguageMode(.v5),
     .enableExperimentalFeature("StrictConcurrency"),

Sources/ComposableArchitecture/Effect.swift

@@ -83,7 +83,7 @@ extension Effect {
   public static func run(
     priority: TaskPriority? = nil,
     operation: @escaping @Sendable (_ send: Send<Action>) async throws -> Void,
-    catch handler: (@Sendable (_ error: Error, _ send: Send<Action>) async -> Void)? = nil,
+    catch handler: (@Sendable (_ error: any Error, _ send: Send<Action>) async -> Void)? = nil,
     fileID: StaticString = #fileID,
     filePath: StaticString = #filePath,
     line: UInt = #line,

Sources/ComposableArchitecture/Effects/Animation.swift

@@ -83,7 +83,7 @@ private struct TransactionPublisher<Upstream: Publisher>: Publisher {
       self.transaction = transaction
     }
 
-    func receive(subscription: Subscription) {
+    func receive(subscription: any Subscription) {
       self.downstream.receive(subscription: subscription)
     }
 

Sources/ComposableArchitecture/Effects/Cancellation.swift

@@ -172,7 +172,7 @@ extension Effect {
   ) async rethrows -> T {
     @Dependency(\.navigationIDPath) var navigationIDPath
 
-    let (cancellable, task): (AnyCancellable, Task<T, Error>) =
+    let (cancellable, task): (AnyCancellable, Task<T, any Error>) =
       _cancellationCancellables
       .withValue {
         if cancelInFlight {
@@ -191,7 +191,7 @@ extension Effect {
     do {
       return try await task.cancellableValue
     } catch {
-      return try Result<T, Error>.failure(error)._rethrowGet()
+      return try Result<T, any Error>.failure(error)._rethrowGet()
     }
   }
 #else
@@ -203,7 +203,7 @@ extension Effect {
   ) async rethrows -> T {
     @Dependency(\.navigationIDPath) var navigationIDPath
 
-    let (cancellable, task): (AnyCancellable, Task<T, Error>) =
+    let (cancellable, task): (AnyCancellable, Task<T, any Error>) =
       _cancellationCancellables
       .withValue {
         if cancelInFlight {
@@ -222,7 +222,7 @@ extension Effect {
     do {
       return try await task.cancellableValue
     } catch {
-      return try Result<T, Error>.failure(error)._rethrowGet()
+      return try Result<T, any Error>.failure(error)._rethrowGet()
     }
   }
 #endif

Sources/ComposableArchitecture/Effects/TaskResult.swift

@@ -4,7 +4,7 @@
 ///
 /// This type is needed because Swift's concurrency tools can only express untyped errors, such as
 /// `async` functions and `AsyncSequence`, and so their output can realistically only be bridged to
-/// `Result<_, Error>`. However, `Result<_, Error>` is never `Equatable` since `Error` is not
+/// `Result<_, any Error>`. However, `Result<_, any Error>` is never `Equatable` since `Error` is not
 /// `Equatable`, and equatability is very important for testing in the Composable Architecture. By
 /// defining our own type we get the ability to recover equatability in most situations.
 ///
@@ -129,7 +129,7 @@ public enum TaskResult<Success: Sendable>: Sendable {
   case success(Success)
 
   /// A failure, storing an error.
-  case failure(Error)
+  case failure(any Error)
 
   /// Creates a new task result by evaluating an async throwing closure, capturing the returned
   /// value as a success, or any thrown error as a failure.
@@ -226,7 +226,7 @@ extension TaskResult: CasePathable {
       )
     }
 
-    public var failure: AnyCasePath<TaskResult, Error> {
+    public var failure: AnyCasePath<TaskResult, any Error> {
       AnyCasePath(
         embed: { .failure($0) },
         extract: {
@@ -238,7 +238,7 @@ extension TaskResult: CasePathable {
   }
 }
 
-extension Result where Success: Sendable, Failure == Error {
+extension Result where Success: Sendable, Failure == any Error {
   /// Transforms a `TaskResult` into a `Result`.
   ///
   /// - Parameter result: A task result.