Implement strict concurrency

Package.swift

@@ -24,17 +24,26 @@ let package = Package(
     targets: [
         .target(
             name: "Meta",
-            path: "Sources"
+            path: "Sources",
+            swiftSettings: [
+                .enableExperimentalFeature("StrictConcurrency")
+            ]
         ),
         .target(
             name: "SampleBackends",
             dependencies: ["Meta"],
-            path: "Tests/SampleBackends"
+            path: "Tests/SampleBackends",
+            swiftSettings: [
+                .enableExperimentalFeature("StrictConcurrency")
+            ]
         ),
         .executableTarget(
             name: "DemoApp",
             dependencies: ["SampleBackends"],
-            path: "Tests/DemoApp"
+            path: "Tests/DemoApp",
+            swiftSettings: [
+                .enableExperimentalFeature("StrictConcurrency")
+            ]
         )
     ]
 )

Sources/Model/Data Flow/State.swift

@@ -13,6 +13,7 @@ import Observation
 public struct State<Value>: StateProtocol {
 
     /// Access the stored value. This updates the views when being changed.
+    @StateManager
     public var wrappedValue: Value {
         get {
             rawValue
@@ -25,6 +26,7 @@ public struct State<Value>: StateProtocol {
     }
 
     /// Get the value as a binding using the `$` prefix.
+    @StateManager
     public var projectedValue: Binding<Value> {
         .init {
             wrappedValue
@@ -34,6 +36,7 @@ public struct State<Value>: StateProtocol {
     }
 
     /// Get and set the value without updating the views.
+    @StateManager
     public var rawValue: Value {
         get {
             guard let value = StateManager.getState(id: id) as? Value else {

Sources/Model/Data Flow/StateManager.swift

@@ -8,18 +8,21 @@
 import Foundation
 
 /// This type manages view updates.
-public enum StateManager {
+@globalActor
+public actor StateManager {
+
+    public static let shared = StateManager()
 
     /// Whether to block updates in general.
-    public static var blockUpdates = false
+    @StateManager static var blockUpdates = false
     /// Whether to save state.
-    public static var saveState = true
+    @StateManager static var saveState = true
     /// The application identifier.
-    static var appID: String?
+    @StateManager static var appID: String?
     /// The functions handling view updates.
-    static var updateHandlers: [(Bool) -> Void] = []
+    @StateManager static var updateHandlers: [(Bool) async -> Void] = []
     /// The state.
-    static var state: [State] = []
+    @StateManager static var state: [State] = []
 
     /// Information about a piece of state.
     struct State {
@@ -50,24 +53,29 @@ public enum StateManager {
     /// - Parameter force: Whether to force all views to update.
     ///
     /// Nothing happens if ``UpdateManager/blockUpdates`` is true.
+    @StateManager
     public static func updateViews(force: Bool = false) {
         if !blockUpdates {
             for handler in updateHandlers {
-                handler(force)
+                Task {
+                    await handler(force)
+                }
             }
         }
     }
 
     /// Add a handler that is called when the user interface should update.
     /// - Parameter handler: The handler. The parameter defines whether the whole UI should be force updated.
-    public static func addUpdateHandler(handler: @escaping (Bool) -> Void) {
+    @StateManager
+    public static func addUpdateHandler(handler: @escaping (Bool) async -> Void) {
         updateHandlers.append(handler)
     }
 
     /// Set the state value for a certain ID.
     /// - Parameters:
     ///   - id: The identifier.
     ///   - value: The new value.
+    @StateManager
     static func setState(id: UUID, value: Any?) {
         if saveState {
             guard let index = state.firstIndex(where: { $0.contains(id: id) }) else {
@@ -81,12 +89,14 @@ public enum StateManager {
     /// Get the state value for a certain ID.
     /// - Parameter id: The identifier.
     /// - Returns: The value.
+    @StateManager
     static func getState(id: UUID) -> Any? {
         state[safe: state.firstIndex { $0.contains(id: id) }]?.value
     }
 
     /// Mark the state of a certain id as updated.
     /// - Parameter id: The identifier.
+    @StateManager
     static func updateState(id: UUID) {
         if saveState {
             state[safe: state.firstIndex { $0.contains(id: id) }]?.update = true
@@ -95,6 +105,7 @@ public enum StateManager {
 
     /// Mark the state of a certain id as not updated.
     /// - Parameter id: The identifier.
+    @StateManager
     static func updatedState(id: UUID) {
         if saveState {
             state[safe: state.firstIndex { $0.contains(id: id) }]?.update = false
@@ -104,6 +115,7 @@ public enum StateManager {
     /// Get whether to update the state of a certain id.
     /// - Parameter id: The identifier.
     /// - Returns: Whether to update the state.
+    @StateManager
     static func getUpdateState(id: UUID) -> Bool {
         state[safe: state.firstIndex { $0.contains(id: id) }]?.update ?? false
     }
@@ -112,10 +124,18 @@ public enum StateManager {
     /// - Parameters:
     ///   - oldID: The old identifier.
     ///   - newID: The new identifier.
+    @StateManager
     static func changeID(old oldID: UUID, new newID: UUID) {
         if saveState {
             state[safe: state.firstIndex { $0.contains(id: oldID) }]?.changeID(new: newID)
         }
     }
 
+    /// Set the app's identifier.
+    /// - Parameter id: The identifier.
+    @StateManager
+    static func setAppID(_ id: String) {
+        appID = id
+    }
+
 }

Sources/Model/User Interface/App/App.swift

@@ -30,7 +30,7 @@ public protocol App {
     /// The app's application ID.
     var id: String { get }
     /// The app's scene.
-    @SceneBuilder var scene: Scene { get }
+    @StateManager @SceneBuilder var scene: Scene { get }
     // swiftlint:disable implicitly_unwrapped_optional
     /// The app storage.
     var app: Storage! { get set }
@@ -44,8 +44,9 @@ public protocol App {
 extension App {
 
     /// The application's entry point.
-    public static func main() {
-        let app = setupApp()
+    @StateManager
+    public static func main() async {
+        let app = await setupApp()
         app.app.run {
             for element in app.scene {
                 element.setupInitialContainers(app: app.app)
@@ -56,26 +57,26 @@ extension App {
     /// Initialize and get the app with the app storage.
     ///
     /// To run the app, call the ``AppStorage/run(automaticSetup:manualSetup:)`` function.
-    public static func setupApp() -> Self {
+    public static func setupApp() async -> Self {
         var appInstance = self.init()
         appInstance.app = Storage(id: appInstance.id) { appInstance }
-        StateManager.addUpdateHandler { force in
+        await StateManager.addUpdateHandler { force in
             var updateProperties = force
             for property in appInstance.getState() {
                 if let oldID = appInstance.app.storage.stateStorage[property.key]?.id {
-                    StateManager.changeID(old: oldID, new: property.value.id)
+                    await StateManager.changeID(old: oldID, new: property.value.id)
                     appInstance.app.storage.stateStorage[property.key]?.id = property.value.id
                 }
-                if StateManager.getUpdateState(id: property.value.id) {
+                if await StateManager.getUpdateState(id: property.value.id) {
                     updateProperties = true
-                    StateManager.updatedState(id: property.value.id)
+                    await StateManager.updatedState(id: property.value.id)
                 }
             }
             var removeIndices: [Int] = []
             for (index, element) in appInstance.app.storage.sceneStorage.enumerated() {
                 if element.destroy {
                     removeIndices.insert(index, at: 0)
-                } else if let scene = appInstance.scene.first(
+                } else if let scene = await appInstance.scene.first(
                     where: { $0.id == element.id }
                 ) as? Storage.SceneElementType as? SceneElement {
                     scene.update(element, app: appInstance.app, updateProperties: updateProperties)
@@ -85,11 +86,13 @@ extension App {
                 appInstance.app.storage.sceneStorage.remove(at: index)
             }
         }
-        StateManager.appID = appInstance.id
+        Task { [appInstance] in
+            await StateManager.setAppID(appInstance.id)
+        }
         let state = appInstance.getState()
         appInstance.app.storage.stateStorage = state
         if #available(macOS 14, *), #available(iOS 17, *), state.contains(where: { $0.value.isObservable }) {
-            appInstance.observe()
+            await appInstance.observe()
         }
         return appInstance
     }
@@ -107,14 +110,15 @@ extension App {
     /// Observe the observable properties accessed in the app.
     @available(macOS, introduced: 14)
     @available(iOS, introduced: 17)
+    @StateManager
     func observe() {
         withObservationTracking {
             _ = scene
         } onChange: {
             Task {
-                StateManager.updateState(id: app.storage.stateStorage.first?.value.id ?? .init())
-                StateManager.updateViews()
-                observe()
+                await StateManager.updateState(id: app.storage.stateStorage.first?.value.id ?? .init())
+                await StateManager.updateViews()
+                await observe()
             }
         }
     }

Sources/Model/User Interface/App/AppStorage.swift

@@ -29,7 +29,8 @@ public protocol AppStorage: AnyObject {
 
     /// Run the application.
     /// - Parameter setup: A closure that is expected to be executed right at the beginning.
-    func run(setup: @escaping () -> Void)
+    @StateManager
+    func run(setup: @StateManager @escaping () -> Void)
 
     /// Terminate the application.
     func quit()
@@ -47,10 +48,12 @@ extension AppStorage {
     /// Add a new scene element with the content of the scene element with a certain id.
     /// - Parameter id: The element's id.
     public func addSceneElement(_ id: String) {
-        if let element = app().scene.last(where: { $0.id == id }) {
-            let container = element.container(app: self)
-            storage.sceneStorage.append(container)
-            showSceneElement(id)
+        Task {
+            if let element = await app().scene.last(where: { $0.id == id }) {
+                let container = element.container(app: self)
+                storage.sceneStorage.append(container)
+                showSceneElement(id)
+            }
         }
     }
 

Sources/Model/User Interface/View/View.swift

@@ -23,13 +23,14 @@
 public protocol View: AnyView {
 
     /// The view's content.
-    @ViewBuilder var view: Body { get }
+    @StateManager @ViewBuilder var view: Body { get }
 
 }
 
 extension View {
 
     /// The view's content.
+    @StateManager
     public var viewContent: Body {
         [StateWrapper(content: { view }, state: getState())]
     }

Sources/View/StateWrapper.swift

@@ -42,21 +42,23 @@ struct StateWrapper: ConvenienceWidget {
         updateProperties: Bool,
         type: Storage.Type
     ) where Storage: AppStorage {
-        var updateProperties = updateProperties
-        for property in state {
-            if let oldID = storage.state[property.key]?.id {
-                StateManager.changeID(old: oldID, new: property.value.id)
-                storage.state[property.key]?.id = property.value.id
+        Task {
+            var updateProperties = updateProperties
+            for property in state {
+                if let oldID = storage.state[property.key]?.id {
+                    await StateManager.changeID(old: oldID, new: property.value.id)
+                    storage.state[property.key]?.id = property.value.id
+                }
+                if await StateManager.getUpdateState(id: property.value.id) {
+                    updateProperties = true
+                    await StateManager.updatedState(id: property.value.id)
+                }
             }
-            if StateManager.getUpdateState(id: property.value.id) {
-                updateProperties = true
-                StateManager.updatedState(id: property.value.id)
+            guard let storage = storage.content[.mainContent]?.first else {
+                return
             }
+            content().updateStorage(storage, modifiers: modifiers, updateProperties: updateProperties, type: type)
         }
-        guard let storage = storage.content[.mainContent]?.first else {
-            return
-        }
-        content().updateStorage(storage, modifiers: modifiers, updateProperties: updateProperties, type: type)
     }
 
     /// Get a view storage.
@@ -86,8 +88,8 @@ struct StateWrapper: ConvenienceWidget {
             _ = content()
         } onChange: {
             Task {
-                StateManager.updateState(id: storage.state.first?.value.id ?? .init())
-                StateManager.updateViews()
+                await StateManager.updateState(id: storage.state.first?.value.id ?? .init())
+                await StateManager.updateViews()
                 observe(storage: storage)
             }
         }

Tests/DemoApp/DemoApp.swift

@@ -4,12 +4,13 @@ import Observation
 import SampleBackends
 
 @main
+@StateManager
 @available(macOS 14, *)
 @available(iOS 17, *)
 struct TestExecutable {
 
-    public static func main() {
-        DemoApp.main()
+    public static func main() async {
+        await DemoApp.main()
         sleep(2)
     }
 

Tests/SampleBackends/Backend1.swift

@@ -183,7 +183,7 @@ public enum Backend1 {
             self.app = app
         }
 
-        public func run(setup: @escaping () -> Void) {
+        public func run(setup: @StateManager @escaping () -> Void) {
             setup()
         }
 

Tests/SampleBackends/Backend2.swift

@@ -78,7 +78,7 @@ public enum Backend2 {
             self.app = app
         }
 
-        public func run(setup: @escaping () -> Void) {
+        public func run(setup: @StateManager @escaping () -> Void) {
             setup()
         }