Enable strict concurrency

bbrk24 · bbrk24 · commit eac5ec3d6de8 · 2025-05-27T21:51:22.000-04:00
diff --git a/Package.swift b/Package.swift
@@ -138,6 +138,9 @@ let package = Package(
                 "Views/TupleViewChildren.swift.gyb",
                 "Views/TableRowContent.swift.gyb",
                 "Scenes/TupleScene.swift.gyb",
+            ],
+            swiftSettings: [
+                .enableUpcomingFeature("StrictConcurrency")
             ]
         ),
         .testTarget(
diff --git a/Sources/HotReloadingMacrosPlugin/HotReloadableAppMacro.swift b/Sources/HotReloadingMacrosPlugin/HotReloadableAppMacro.swift
@@ -104,7 +104,7 @@ extension HotReloadableAppMacro: MemberMacro {
 
                     if !hotReloadingHasConnectedToServer {
                         hotReloadingHasConnectedToServer = true
-                        Task {
+                        Task { @MainActor
                             do {
                                 var client = try await HotReloadingClient()
                                 print("Hot reloading: received new dylib")
diff --git a/Sources/SwiftCrossUI/App.swift b/Sources/SwiftCrossUI/App.swift
@@ -25,14 +25,16 @@ public protocol App {
 
 /// Force refresh the entire scene graph. Used by hot reloading. If you need to do
 /// this in your own code then something has gone very wrong...
+@MainActor
 public var _forceRefresh: () -> Void = {}
 
 /// Metadata embedded by Swift Bundler if present. Loaded at app start up.
+@MainActor
 private var swiftBundlerAppMetadata: AppMetadata?
 
 /// An error encountered when parsing Swift Bundler metadata.
 private enum SwiftBundlerMetadataError: LocalizedError {
-    case jsonNotDictionary(Any)
+    case jsonNotDictionary(String)
     case missingAppIdentifier
     case missingAppVersion
 
@@ -95,7 +97,7 @@ extension App {
             // require a lot of boilerplate code to parse with Codable).
             let jsonValue = try JSONSerialization.jsonObject(with: jsonData)
             guard let json = jsonValue as? [String: Any] else {
-                throw SwiftBundlerMetadataError.jsonNotDictionary(jsonValue)
+                throw SwiftBundlerMetadataError.jsonNotDictionary(String(describing: jsonValue))
             }
             guard let identifier = json["appIdentifier"] as? String else {
                 throw SwiftBundlerMetadataError.missingAppIdentifier
diff --git a/Sources/SwiftCrossUI/Environment/Actions/AlertAction.swift b/Sources/SwiftCrossUI/Environment/Actions/AlertAction.swift
@@ -4,9 +4,9 @@
 /// This exists to avoid having to expose internal details of ``Button``, since
 /// breaking ``Button``'s API would have much more wide-reaching impacts than
 /// breaking this single-purpose API.
-public struct AlertAction {
+public struct AlertAction: Sendable {
     public static let ok = AlertAction(label: "Ok", action: {})
 
     public var label: String
-    public var action: () -> Void
+    public var action: @MainActor @Sendable () -> Void
 }
diff --git a/Sources/SwiftCrossUI/Layout/ViewSize.swift b/Sources/SwiftCrossUI/Layout/ViewSize.swift
@@ -5,7 +5,7 @@
 /// stored separately to make it extra clear that they don't always form some
 /// sort of achievable minimum/maximum size. The provided minimum/maximum bounds
 /// may only be achievable along a single axis at a time.
-public struct ViewSize: Equatable {
+public struct ViewSize: Equatable, Sendable {
     /// The view update result for an empty view.
     public static let empty = ViewSize(
         size: .zero,
diff --git a/Sources/SwiftCrossUI/Scenes/CommandMenu.swift b/Sources/SwiftCrossUI/Scenes/CommandMenu.swift
@@ -1,4 +1,4 @@
-public struct CommandMenu {
+public struct CommandMenu: Sendable {
     var name: String
     var content: [MenuItem]
 
diff --git a/Sources/SwiftCrossUI/Scenes/Commands.swift b/Sources/SwiftCrossUI/Scenes/Commands.swift
@@ -1,5 +1,5 @@
-public struct Commands {
-    public static var empty = Commands(menus: [])
+public struct Commands: Sendable {
+    public static let empty = Commands(menus: [])
 
     var menus: [CommandMenu]
 
diff --git a/Sources/SwiftCrossUI/Values/Axis.swift b/Sources/SwiftCrossUI/Values/Axis.swift
@@ -6,7 +6,7 @@ public enum Axis: Sendable {
     case vertical
 
     /// A set of axes represented as an efficient bit field.
-    public struct Set: OptionSet {
+    public struct Set: OptionSet, Sendable {
         /// The horizontal axis.
         public static let horizontal = Set(rawValue: 1)
         /// The vertical axis.
diff --git a/Sources/SwiftCrossUI/Values/ContentType.swift b/Sources/SwiftCrossUI/Values/ContentType.swift
@@ -1,5 +1,5 @@
 /// A content type corresponding to a specific file/data format.
-public struct ContentType {
+public struct ContentType: Sendable {
     public static let html = ContentType(
         name: "HTML",
         mimeTypes: ["text/html"],
diff --git a/Sources/SwiftCrossUI/Values/Edge.swift b/Sources/SwiftCrossUI/Values/Edge.swift
@@ -10,7 +10,7 @@ public enum Edge: Int8, CaseIterable, Hashable, Sendable {
     case trailing
 
     /// An efficient set of Edges.
-    public struct Set: OptionSet, Hashable {
+    public struct Set: OptionSet, Hashable, Sendable {
         public let rawValue: Int8
 
         public init(rawValue: Int8) {
diff --git a/Sources/SwiftCrossUI/ViewGraph/PreferenceValues.swift b/Sources/SwiftCrossUI/ViewGraph/PreferenceValues.swift
@@ -1,13 +1,13 @@
 import Foundation
 
-public struct PreferenceValues {
+public struct PreferenceValues: Sendable {
     public static let `default` = PreferenceValues(
         onOpenURL: nil
     )
 
-    public var onOpenURL: ((URL) -> Void)?
+    public var onOpenURL: (@Sendable @MainActor (URL) -> Void)?
 
-    public init(onOpenURL: ((URL) -> Void)?) {
+    public init(onOpenURL: (@Sendable @MainActor (URL) -> Void)?) {
         self.onOpenURL = onOpenURL
     }
 
diff --git a/Sources/SwiftCrossUI/ViewGraph/ViewGraphNode.swift b/Sources/SwiftCrossUI/ViewGraph/ViewGraphNode.swift
@@ -4,7 +4,8 @@ import Foundation
 ///
 /// This is where updates are initiated when a view's state updates, and where state is persisted
 /// even when a view gets recomputed by its parent.
-public class ViewGraphNode<NodeView: View, Backend: AppBackend> {
+@MainActor
+public class ViewGraphNode<NodeView: View, Backend: AppBackend>: Sendable {
     /// The view's single widget for the entirety of its lifetime in the view graph.
     ///
     public var widget: Backend.Widget {
@@ -52,7 +53,6 @@ public class ViewGraphNode<NodeView: View, Backend: AppBackend> {
 
     /// Creates a node for a given view while also creating the nodes for its children, creating
     /// the view's widget, and starting to observe its state for changes.
-    @MainActor
     public init(
         for nodeView: NodeView,
         backend: Backend,
@@ -132,15 +132,16 @@ public class ViewGraphNode<NodeView: View, Backend: AppBackend> {
 
     /// Stops observing the view's state.
     deinit {
-        for cancellable in cancellables {
-            cancellable.cancel()
+        Task { @MainActor [cancellables] in
+            for cancellable in cancellables {
+                cancellable.cancel()
+            }
         }
     }
 
     /// Triggers the view to be updated as part of a bottom-up chain of updates (where either the
     /// current view gets updated due to a state change and has potential to trigger its parent to
     /// update as well, or the current view's child has propagated such an update upwards).
-    @MainActor
     private func bottomUpUpdate() {
         // First we compute what size the view will be after the update. If it will change size,
         // propagate the update to this node's parent instead of updating straight away.
@@ -187,7 +188,6 @@ public class ViewGraphNode<NodeView: View, Backend: AppBackend> {
     /// is provided (in the case that the parent's body got updated) then it simply replaces the
     /// old view while inheriting the old view's state.
     /// - Parameter dryRun: If `true`, only compute sizing and don't update the underlying widget.
-    @MainActor
     public func update(
         with newView: NodeView? = nil,
         proposedSize: SIMD2<Int>,
diff --git a/Sources/SwiftCrossUI/Views/Button.swift b/Sources/SwiftCrossUI/Views/Button.swift
@@ -1,14 +1,14 @@
 /// A control that initiates an action.
-public struct Button {
+public struct Button: Sendable {
     /// The label to show on the button.
     package var label: String
     /// The action to be performed when the button is clicked.
-    package var action: @MainActor () -> Void
+    package var action: @MainActor @Sendable () -> Void
     /// The button's forced width if provided.
     var width: Int?
 
     /// Creates a button that displays a custom label.
-    public init(_ label: String, action: @escaping @MainActor () -> Void = {}) {
+    public init(_ label: String, action: @escaping @MainActor @Sendable () -> Void = {}) {
         self.label = label
         self.action = action
     }
diff --git a/Sources/SwiftCrossUI/Views/Menu.swift b/Sources/SwiftCrossUI/Views/Menu.swift
@@ -2,7 +2,7 @@
 ///
 /// Due to technical limitations, the minimum supported OS's for menu buttons in UIKitBackend
 /// are iOS 14 and tvOS 17.
-public struct Menu {
+public struct Menu: Sendable {
     public var label: String
     public var items: [MenuItem]
 
diff --git a/Sources/SwiftCrossUI/Views/MenuItem.swift b/Sources/SwiftCrossUI/Views/MenuItem.swift
@@ -1,5 +1,5 @@
 /// An item of a ``Menu`` or ``CommandMenu``.
-public enum MenuItem {
+public enum MenuItem: Sendable {
     case button(Button)
     case text(Text)
     case submenu(Menu)
diff --git a/Sources/SwiftCrossUI/Views/Modifiers/Lifecycle/OnAppearModifier.swift b/Sources/SwiftCrossUI/Views/Modifiers/Lifecycle/OnAppearModifier.swift
@@ -6,14 +6,14 @@ extension View {
     /// view's ``View/body`` and before the view appears on screen. Currently,
     /// if these docs have been kept up to date, the action gets called just
     /// before creating the view's widget.
-    public func onAppear(perform action: @escaping () -> Void) -> some View {
+    public func onAppear(perform action: @escaping @MainActor () -> Void) -> some View {
         OnAppearModifier(body: TupleView1(self), action: action)
     }
 }
 
 struct OnAppearModifier<Content: View>: View {
     var body: TupleView1<Content>
-    var action: () -> Void
+    var action: @MainActor () -> Void
 
     func asWidget<Backend: AppBackend>(
         _ children: any ViewGraphNodeChildren,
diff --git a/Sources/SwiftCrossUI/Views/Modifiers/Lifecycle/OnDisappearModifier.swift b/Sources/SwiftCrossUI/Views/Modifiers/Lifecycle/OnDisappearModifier.swift
@@ -4,14 +4,15 @@ extension View {
     /// `onDisappear` actions on outermost views are called first and propagate
     /// down to the leaf views due to essentially relying on the `deinit` of the
     /// modifier view's ``ViewGraphNode``.
-    public func onDisappear(perform action: @escaping () -> Void) -> some View {
+    public func onDisappear(perform action: @escaping @Sendable @MainActor () -> Void) -> some View
+    {
         OnDisappearModifier(body: TupleView1(self), action: action)
     }
 }
 
 struct OnDisappearModifier<Content: View>: View {
     var body: TupleView1<Content>
-    var action: () -> Void
+    var action: @Sendable @MainActor () -> Void
 
     func children<Backend: AppBackend>(
         backend: Backend,
@@ -66,7 +67,7 @@ struct OnDisappearModifier<Content: View>: View {
 
 class OnDisappearModifierChildren: ViewGraphNodeChildren {
     var wrappedChildren: any ViewGraphNodeChildren
-    var action: () -> Void
+    var action: @Sendable @MainActor () -> Void
 
     var widgets: [AnyWidget] {
         wrappedChildren.widgets
@@ -78,13 +79,15 @@ class OnDisappearModifierChildren: ViewGraphNodeChildren {
 
     init(
         wrappedChildren: any ViewGraphNodeChildren,
-        action: @escaping () -> Void
+        action: @escaping @Sendable @MainActor () -> Void
     ) {
         self.wrappedChildren = wrappedChildren
         self.action = action
     }
 
     deinit {
-        action()
+        Task { @MainActor [action] in
+            action()
+        }
     }
 }
diff --git a/Sources/SwiftCrossUI/Views/Modifiers/Lifecycle/TaskModifier.swift b/Sources/SwiftCrossUI/Views/Modifiers/Lifecycle/TaskModifier.swift
@@ -34,14 +34,16 @@ extension View {
     }
 }
 
-struct TaskModifier<Id: Equatable, Content: View>: View {
+struct TaskModifier<Id: Equatable, Content: View> {
     @State var task: Task<(), any Error>? = nil
 
     var id: Id
     var content: Content
     var priority: TaskPriority
     var action: () async -> Void
+}
 
+extension TaskModifier: View {
     var body: some View {
         // Explicitly return to disable result builder (we don't want an extra
         // layer of views).
diff --git a/Sources/SwiftCrossUI/Views/Shapes/Capsule.swift b/Sources/SwiftCrossUI/Views/Shapes/Capsule.swift
@@ -1,8 +1,8 @@
 /// A rounded rectangle whose corner radius is equal to half the length of its shortest side.
 public struct Capsule: Shape {
-    public init() {}
+    public nonisolated init() {}
 
-    public func path(in bounds: Path.Rect) -> Path {
+    public nonisolated func path(in bounds: Path.Rect) -> Path {
         let radius = min(bounds.width, bounds.height) / 2.0
         return RoundedRectangle(cornerRadius: radius).path(in: bounds)
     }
diff --git a/Sources/SwiftCrossUI/Views/Shapes/Circle.swift b/Sources/SwiftCrossUI/Views/Shapes/Circle.swift
@@ -1,12 +1,12 @@
 public struct Circle: Shape {
-    public init() {}
+    public nonisolated init() {}
 
-    public func path(in bounds: Path.Rect) -> Path {
+    public nonisolated func path(in bounds: Path.Rect) -> Path {
         Path()
             .addCircle(center: bounds.center, radius: min(bounds.width, bounds.height) / 2.0)
     }
 
-    public func size(fitting proposal: SIMD2<Int>) -> ViewSize {
+    public nonisolated func size(fitting proposal: SIMD2<Int>) -> ViewSize {
         let diameter = min(proposal.x, proposal.y)
 
         return ViewSize(
diff --git a/Sources/SwiftCrossUI/Views/Shapes/Ellipse.swift b/Sources/SwiftCrossUI/Views/Shapes/Ellipse.swift
@@ -1,7 +1,7 @@
 public struct Ellipse: Shape {
-    public init() {}
+    public nonisolated init() {}
 
-    public func path(in bounds: Path.Rect) -> Path {
+    public nonisolated func path(in bounds: Path.Rect) -> Path {
         Path()
             .addCircle(center: .zero, radius: bounds.width / 2.0)
             .applyTransform(
diff --git a/Sources/SwiftCrossUI/Views/Shapes/Rectangle.swift b/Sources/SwiftCrossUI/Views/Shapes/Rectangle.swift
@@ -1,7 +1,7 @@
 public struct Rectangle: Shape {
-    public init() {}
+    public nonisolated init() {}
 
-    public func path(in bounds: Path.Rect) -> Path {
+    public nonisolated func path(in bounds: Path.Rect) -> Path {
         Path().addRectangle(bounds)
     }
 }
diff --git a/Sources/SwiftCrossUI/Views/Shapes/RoundedRectangle.swift b/Sources/SwiftCrossUI/Views/Shapes/RoundedRectangle.swift
@@ -2,7 +2,7 @@
 ///
 /// This is not necessarily four line segments and four circular arcs. If possible, this shape
 /// uses smoother curves to make the transition between the edges and corners less abrupt.
-public struct RoundedRectangle: Shape {
+public struct RoundedRectangle {
     public var cornerRadius: Double
 
     public init(cornerRadius: Double) {
@@ -20,7 +20,7 @@ public struct RoundedRectangle: Shape {
     // Preconditions:
     //   - points.0 is the same as if a line segment and a circular arc were used
     //   - points.6.y == 0.0
-    private static let points = (
+    fileprivate static let points = (
         SIMD2(0.292893218813, 0.292893218813),
         SIMD2(0.517, 0.0687864376269),
         SIMD2(0.87, 0.0337),
@@ -33,8 +33,10 @@ public struct RoundedRectangle: Shape {
     // This corresponds to r_{min} in the above Desmos link. This is the minimum ratio of
     // cornerRadius to half the side length at which the superellipse is not applicable. Above this,
     // line segments and circular arcs are used.
-    private static let rMin = 0.441968022436
+    fileprivate static let rMin = 0.441968022436
+}
 
+extension RoundedRectangle: Shape {
     public func path(in bounds: Path.Rect) -> Path {
         // just to avoid `RoundedRectangle.` qualifiers
         let rMin = RoundedRectangle.rMin
diff --git a/Sources/SwiftCrossUI/Views/Text.swift b/Sources/SwiftCrossUI/Views/Text.swift
@@ -1,5 +1,5 @@
 /// A text view.
-public struct Text {
+public struct Text: Sendable {
     /// The string to be shown in the text view.
     var string: String
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-public struct CommandMenu {`
	`1`	`+public struct CommandMenu: Sendable {`
`2`	`2`	`var name: String`
`3`	`3`	`var content: [MenuItem]`
`4`	`4`