Address @Shared sendability.

Package.resolved

@@ -93,7 +93,7 @@
     {
       "identity" : "swift-docc-symbolkit",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/apple/swift-docc-symbolkit",
+      "location" : "https://github.com/swiftlang/swift-docc-symbolkit",
       "state" : {
         "revision" : "b45d1f2ed151d057b54504d653e0da5552844e34",
         "version" : "1.0.0"

Package.swift

@@ -87,7 +87,7 @@ let package = Package(
 )
 
 #if compiler(>=6)
-  for target in package.targets where target.type != .system {
+  for target in package.targets where target.type != .system && target.type != .test {
     target.swiftSettings = target.swiftSettings ?? []
     target.swiftSettings?.append(contentsOf: [
       .enableExperimentalFeature("StrictConcurrency"),

Sources/ComposableArchitecture/Internal/AnySendable.swift

@@ -0,0 +1,7 @@
+struct AnySendable: @unchecked Sendable {
+  let base: Any
+  @inlinable
+  init<Base: Sendable>(_ base: Base) {
+    self.base = base
+  }
+}

Sources/ComposableArchitecture/SharedState/PersistenceKey.swift

@@ -7,9 +7,9 @@
 ///
 /// See the article <doc:SharingState> for more information, in particular the
 /// <doc:SharingState#Custom-persistence> section.
-public protocol PersistenceReaderKey<Value> {
+public protocol PersistenceReaderKey<Value>: Sendable {
   /// A type that can be loaded or subscribed to in an external system.
-  associatedtype Value
+  associatedtype Value: Sendable
 
   /// A type representing the hashable identity of a persistence key.
   associatedtype ID: Hashable = Self

Sources/ComposableArchitecture/SharedState/PersistenceKey/AppStorageKey.swift

@@ -154,7 +154,7 @@ extension PersistenceReaderKey {
 /// A type defining a user defaults persistence strategy.
 ///
 /// See ``PersistenceReaderKey/appStorage(_:)-4l5b`` to create values of this type.
-public struct AppStorageKey<Value> {
+public struct AppStorageKey<Value: Sendable>: Sendable {
   private let lookup: any Lookup<Value>
   private let key: String
   private let store: UserDefaults
@@ -362,13 +362,13 @@ private enum SharedAppStorageLocals {
   @TaskLocal static var isSetting = false
 }
 
-private protocol Lookup<Value> {
-  associatedtype Value
+private protocol Lookup<Value>: Sendable {
+  associatedtype Value: Sendable
   func loadValue(from store: UserDefaults, at key: String, default defaultValue: Value?) -> Value?
   func saveValue(_ newValue: Value, to store: UserDefaults, at key: String)
 }
 
-private struct CastableLookup<Value>: Lookup {
+private struct CastableLookup<Value: Sendable>: Lookup, Sendable {
   func loadValue(
     from store: UserDefaults,
     at key: String,
@@ -421,7 +421,7 @@ private struct URLLookup: Lookup {
   }
 }
 
-private struct RawRepresentableLookup<Value: RawRepresentable, Base: Lookup>: Lookup
+private struct RawRepresentableLookup<Value: RawRepresentable & Sendable, Base: Lookup>: Lookup, Sendable
 where Value.RawValue == Base.Value {
   let base: Base
   func loadValue(

Sources/ComposableArchitecture/SharedState/PersistenceKey/AppStorageKeyPathKey.swift

@@ -15,7 +15,7 @@ extension PersistenceReaderKey {
   /// - Parameter key: A string key identifying a value to share in memory.
   /// - Returns: A persistence key.
   public static func appStorage<Value>(
-    _ keyPath: ReferenceWritableKeyPath<UserDefaults, Value>
+    _ keyPath: _ReferenceWritableKeyPath<UserDefaults, Value>
   ) -> Self where Self == AppStorageKeyPathKey<Value> {
     AppStorageKeyPathKey(keyPath)
   }
@@ -24,33 +24,34 @@ extension PersistenceReaderKey {
 /// A type defining a user defaults persistence strategy via key path.
 ///
 /// See ``PersistenceReaderKey/appStorage(_:)-5jsie`` to create values of this type.
-public struct AppStorageKeyPathKey<Value> {
-  private let keyPath: ReferenceWritableKeyPath<UserDefaults, Value>
-  private let store: UserDefaults
+public struct AppStorageKeyPathKey<Value: Sendable>: Sendable {
+
+  private let keyPath: _ReferenceWritableKeyPath<UserDefaults, Value>
+  private let store: UncheckedSendable<UserDefaults>
 
-  public init(_ keyPath: ReferenceWritableKeyPath<UserDefaults, Value>) {
+  public init(_ keyPath: _ReferenceWritableKeyPath<UserDefaults, Value>) {
     @Dependency(\.defaultAppStorage) var store
     self.keyPath = keyPath
-    self.store = store
+    self.store = UncheckedSendable(store)
   }
 }
 
 extension AppStorageKeyPathKey: PersistenceKey, Hashable {
   public func load(initialValue _: Value?) -> Value? {
-    self.store[keyPath: self.keyPath]
+    self.store.wrappedValue[keyPath: self.keyPath]
   }
 
   public func save(_ newValue: Value) {
     SharedAppStorageLocals.$isSetting.withValue(true) {
-      self.store[keyPath: self.keyPath] = newValue
+      self.store.wrappedValue[keyPath: self.keyPath] = newValue
     }
   }
 
   public func subscribe(
     initialValue: Value?,
     didSet: @escaping @Sendable (_ newValue: Value?) -> Void
   ) -> Shared<Value>.Subscription {
-    let observer = self.store.observe(self.keyPath, options: .new) { _, change in
+    let observer = self.store.wrappedValue.observe(self.keyPath, options: .new) { _, change in
       guard
         !SharedAppStorageLocals.isSetting
       else { return }

Sources/ComposableArchitecture/SharedState/PersistenceKey/FileStorageKey.swift

@@ -50,8 +50,6 @@ public final class FileStorageKey<Value: Sendable>: PersistenceKey, Sendable {
   private let decode: @Sendable (Data) throws -> Value
   private let encode: @Sendable (Value) throws -> Data
   fileprivate let state = LockIsolated(State())
-  //  private let value = LockIsolated<Value?>(nil)
-  //  private let workItem = LockIsolated<DispatchWorkItem?>(nil)
 
   fileprivate struct State {
     var value: Value?
@@ -262,7 +260,7 @@ public struct FileStorage: Hashable, Sendable {
   let createDirectory: @Sendable (URL, Bool) throws -> Void
   let fileExists: @Sendable (URL) -> Bool
   let fileSystemSource:
-    @Sendable (URL, DispatchSource.FileSystemEvent, @escaping () -> Void) -> AnyCancellable
+  @Sendable (URL, DispatchSource.FileSystemEvent, @escaping @Sendable () -> Void) -> AnyCancellable
   let load: @Sendable (URL) throws -> Data
   @_spi(Internals) public let save: @Sendable (Data, URL) throws -> Void
 
@@ -271,7 +269,7 @@ public struct FileStorage: Hashable, Sendable {
   ///
   /// This is the version of the ``Dependencies/DependencyValues/defaultFileStorage`` dependency
   /// that is used by default when running your app in the simulator or on device.
-  public static var fileSystem = fileSystem(
+  public static let fileSystem = fileSystem(
     queue: DispatchQueue(label: "co.pointfree.ComposableArchitecture.FileStorage")
   )
 
@@ -345,9 +343,9 @@ public struct FileStorage: Hashable, Sendable {
     )
   }
 
-  fileprivate struct Handler: Hashable {
+  fileprivate struct Handler: Hashable, Sendable {
     let id = UUID()
-    let operation: () -> Void
+    let operation: @Sendable () -> Void
     static func == (lhs: Self, rhs: Self) -> Bool {
       lhs.id == rhs.id
     }

Sources/ComposableArchitecture/SharedState/PersistenceKey/InMemoryKey.swift

@@ -23,7 +23,7 @@ extension PersistenceReaderKey {
 /// A type defining an in-memory persistence strategy
 ///
 /// See ``PersistenceReaderKey/inMemory(_:)`` to create values of this type.
-public struct InMemoryKey<Value>: PersistenceKey, Sendable {
+public struct InMemoryKey<Value: Sendable>: PersistenceKey, Sendable {
   private let key: String
   private let store: InMemoryStorage
   fileprivate init(_ key: String) {

Sources/ComposableArchitecture/SharedState/PersistenceKey/PersistenceKeyDefault.swift

@@ -24,9 +24,9 @@
 /// ```
 public struct PersistenceKeyDefault<Base: PersistenceReaderKey>: PersistenceReaderKey {
   let base: Base
-  let defaultValue: () -> Base.Value
+  let defaultValue: @Sendable () -> Base.Value
 
-  public init(_ key: Base, _ value: @autoclosure @escaping () -> Base.Value) {
+  public init(_ key: Base, _ value: @autoclosure @escaping @Sendable () -> Base.Value) {
     self.base = key
     self.defaultValue = value
   }

Sources/ComposableArchitecture/SharedState/Reference.swift

@@ -2,8 +2,8 @@
   import Combine
 #endif
 
-protocol Reference<Value>: AnyObject, CustomStringConvertible {
-  associatedtype Value
+protocol Reference<Value>: AnyObject, CustomStringConvertible, Sendable {
+  associatedtype Value: Sendable
   var value: Value { get set }
 
   func access()

Sources/ComposableArchitecture/SharedState/References/ValueReference.swift

@@ -17,7 +17,7 @@ extension Shared {
   ///   - persistenceKey: A persistence key associated with the shared reference. It is responsible
   ///     for loading and saving the shared reference's value from some external source.
   public init(
-    wrappedValue value: @autoclosure @escaping () -> Value,
+    wrappedValue value: @autoclosure @escaping @Sendable () -> Value,
     _ persistenceKey: some PersistenceKey<Value>,
     fileID: StaticString = #fileID,
     line: UInt = #line
@@ -93,7 +93,7 @@ extension Shared {
   }
 
   private init(
-    throwingValue value: @autoclosure @escaping () throws -> Value,
+    throwingValue value: @autoclosure @escaping @Sendable () throws -> Value,
     _ persistenceKey: some PersistenceKey<Value>,
     fileID: StaticString = #fileID,
     line: UInt = #line
@@ -154,7 +154,7 @@ extension Shared {
   ///   - persistenceKey: A persistence key associated with the shared reference. It is responsible
   ///     for loading and saving the shared reference's value from some external source.
   public init<Key: PersistenceKey<Value>>(
-    wrappedValue value: @autoclosure @escaping () -> Value,
+    wrappedValue value: @autoclosure @escaping @Sendable () -> Value,
     _ persistenceKey: PersistenceKeyDefault<Key>,
     fileID: StaticString = #fileID,
     line: UInt = #line
@@ -177,7 +177,7 @@ extension SharedReader {
   ///   - persistenceKey: A persistence key associated with the shared reference. It is responsible
   ///     for loading the shared reference's value from some external source.
   public init(
-    wrappedValue value: @autoclosure @escaping () -> Value,
+    wrappedValue value: @autoclosure @escaping @Sendable () -> Value,
     _ persistenceKey: some PersistenceReaderKey<Value>,
     fileID: StaticString = #fileID,
     line: UInt = #line
@@ -252,7 +252,7 @@ extension SharedReader {
   }
 
   private init(
-    throwingValue value: @autoclosure @escaping () throws -> Value,
+    throwingValue value: @autoclosure @escaping @Sendable () throws -> Value,
     _ persistenceKey: some PersistenceReaderKey<Value>,
     fileID: StaticString = #fileID,
     line: UInt = #line
@@ -312,7 +312,7 @@ extension SharedReader {
   ///   - persistenceKey: A persistence key associated with the shared reference. It is responsible
   ///     for loading the shared reference's value from some external source.
   public init<Key: PersistenceReaderKey<Value>>(
-    wrappedValue value: @autoclosure @escaping () -> Value,
+    wrappedValue value: @autoclosure @escaping @Sendable () -> Value,
     _ persistenceKey: PersistenceKeyDefault<Key>,
     fileID: StaticString = #fileID,
     line: UInt = #line
@@ -328,15 +328,15 @@ extension SharedReader {
 
 private struct LoadError: Error {}
 
-final class ValueReference<Value, Persistence: PersistenceReaderKey<Value>>: Reference, @unchecked
-  Sendable
+final class ValueReference<Value, Persistence: PersistenceReaderKey<Value>>: Reference,
+  @unchecked Sendable
 {
   private let lock = NSRecursiveLock()
   private let persistenceKey: Persistence?
   #if canImport(Combine)
     private let subject: CurrentValueRelay<Value>
   #endif
-  private var subscription: Shared<Value>.Subscription?
+  private var subscription: Shared<Value>.Subscription!
   private var _value: Value {
     willSet {
       self.subject.send(newValue)

Sources/ComposableArchitecture/SharedState/Shared.swift

@@ -12,7 +12,7 @@ import IssueReporting
 /// wrapper.
 @dynamicMemberLookup
 @propertyWrapper
-public struct Shared<Value> {
+public struct Shared<Value: Sendable> {
   private let reference: any Reference
   private let keyPath: AnyKeyPath
 
@@ -275,7 +275,7 @@ public struct Shared<Value> {
 
   private var snapshot: Value? {
     get {
-      func open<Root>(_ reference: some Reference<Root>) -> Value? {
+      func open<Root: Sendable>(_ reference: some Reference<Root>) -> Value? {
         @Dependency(\.sharedChangeTracker) var changeTracker
         return changeTracker?[reference]?.snapshot[
           keyPath: unsafeDowncast(self.keyPath, to: WritableKeyPath<Root, Value>.self)
@@ -284,7 +284,7 @@ public struct Shared<Value> {
       return open(self.reference)
     }
     nonmutating set {
-      func open<Root>(_ reference: some Reference<Root>) {
+      func open<Root: Sendable>(_ reference: some Reference<Root>) {
         @Dependency(\.sharedChangeTracker) var changeTracker
         guard let newValue else {
           changeTracker?[reference] = nil
@@ -344,7 +344,10 @@ extension Shared: _CustomDiffObject {
 }
 
 extension Shared
-where Value: _MutableIdentifiedCollection {
+where
+  Value: _MutableIdentifiedCollection,
+  Value.Element: Sendable
+{
   /// Allows a `ForEach` view to transform a shared collection into shared elements.
   ///
   /// ```swift
@@ -408,11 +411,10 @@ extension Shared: MutableCollection
 where Value: MutableCollection & RandomAccessCollection, Value.Index: Hashable {
   public subscript(position: Value.Index) -> Shared<Value.Element> {
     get {
-      assertionFailure("Conformance of 'Shared<Value>' to 'MutableCollection' is unavailable.")
-      return self[position, default: DefaultSubscript(self.wrappedValue[position])]
+      fatalError("Conformance of 'Shared<Value>' to 'MutableCollection' is unavailable.")
     }
     set {
-      self._wrappedValue[position] = newValue.wrappedValue
+      fatalError("Conformance of 'Shared<Value>' to 'MutableCollection' is unavailable.")
     }
   }
 }

Sources/ComposableArchitecture/SharedState/SharedChangeTracking.swift

@@ -46,7 +46,7 @@ extension Change {
   }
 }
 
-struct AnyChange<Value>: Change {
+struct AnyChange<Value: Sendable>: Change, Sendable {
   let reference: any Reference<Value>
   var snapshot: Value
 
@@ -58,7 +58,7 @@ struct AnyChange<Value>: Change {
 
 @_spi(Internals)
 public final class SharedChangeTracker: Sendable {
-  let changes: LockIsolated<[ObjectIdentifier: Any]> = LockIsolated([:])
+  let changes: LockIsolated<[ObjectIdentifier: AnySendable]> = LockIsolated([:])
   var hasChanges: Bool { !self.changes.isEmpty }
   @_spi(Internals) public init() {}
   func resetChanges() { self.changes.withValue { $0.removeAll() } }
@@ -70,17 +70,17 @@ public final class SharedChangeTracker: Sendable {
     }
     self.resetChanges()
   }
-  func track<Value>(_ reference: some Reference<Value>) {
+  func track<Value: Sendable>(_ reference: some Reference<Value>) {
     if !self.changes.keys.contains(ObjectIdentifier(reference)) {
-      self.changes.withValue { $0[ObjectIdentifier(reference)] = AnyChange(reference) }
+      self.changes.withValue { $0[ObjectIdentifier(reference)] = AnySendable(AnyChange(reference)) }
     }
   }
   subscript<Value>(_ reference: some Reference<Value>) -> AnyChange<Value>? {
-    _read { yield self.changes[ObjectIdentifier(reference)] as? AnyChange<Value> }
+    _read { yield self.changes[ObjectIdentifier(reference)]?.base as? AnyChange<Value> }
     _modify {
-      var change = self.changes[ObjectIdentifier(reference)] as? AnyChange<Value>
+      var change = self.changes[ObjectIdentifier(reference)]?.base as? AnyChange<Value>
       yield &change
-      self.changes.withValue { [change] in $0[ObjectIdentifier(reference)] = change }
+      self.changes.withValue { [change] in $0[ObjectIdentifier(reference)] = AnySendable(change) }
     }
   }
   func track<R>(_ operation: () throws -> R) rethrows -> R {

Sources/ComposableArchitecture/SharedState/SharedReader.swift

@@ -8,7 +8,7 @@
 /// wrapper, in particular <doc:SharingState#Read-only-shared-state>.
 @dynamicMemberLookup
 @propertyWrapper
-public struct SharedReader<Value> {
+public struct SharedReader<Value: Sendable> {
   fileprivate let reference: any Reference
   fileprivate let keyPath: AnyKeyPath
 
@@ -47,7 +47,7 @@ public struct SharedReader<Value> {
     else { return nil }
     self.init(
       reference: base.reference,
-      keyPath: base.keyPath.appending(path: \Value?.[default:DefaultSubscript(initialValue)])!
+      keyPath: base.keyPath.appending(path: \Value?.[default: DefaultSubscript(initialValue)])!
     )
   }
 
@@ -183,7 +183,11 @@ extension SharedReader: CustomDumpRepresentable {
 }
 
 extension SharedReader
-where Value: RandomAccessCollection & MutableCollection, Value.Index: Hashable & Sendable {
+where
+  Value: RandomAccessCollection & MutableCollection,
+  Value.Index: Hashable & Sendable,
+  Value.Element: Sendable
+{
   /// Derives a collection of read-only shared elements from a read-only shared collection of
   /// elements.
   ///