AppStorage: add support for Date values

Sources/ComposableArchitecture/SharedState/PersistenceKey/AppStorageKey.swift

@@ -47,6 +47,15 @@ extension PersistenceReaderKey {
     AppStorageKey(key)
   }
 
+  /// Creates a persistence key that can read and write to a Date user default.
+  ///
+  /// - Parameter key: The key to read and write the value to in the user defaults store.
+  /// - Returns: A user defaults persistence key.
+  public static func appStorage(_ key: String) -> Self
+  where Self == AppStorageKey<Date> {
+    AppStorageKey(key)
+  }
+
   /// Creates a persistence key that can read and write to a user default as data.
   ///
   /// - Parameter key: The key to read and write the value to in the user defaults store.
@@ -121,6 +130,15 @@ extension PersistenceReaderKey {
     AppStorageKey(key)
   }
 
+  /// Creates a persistence key that can read and write to an optional Date user default.
+  ///
+  /// - Parameter key: The key to read and write the value to in the user defaults store.
+  /// - Returns: A user defaults persistence key.
+  public static func appStorage(_ key: String) -> Self
+  where Self == AppStorageKey<Date?> {
+    AppStorageKey(key)
+  }
+
   /// Creates a persistence key that can read and write to a user default as optional data.
   ///
   /// - Parameter key: The key to read and write the value to in the user defaults store.
@@ -198,6 +216,13 @@ public struct AppStorageKey<Value: Sendable>: Sendable {
     self.store = UncheckedSendable(store)
   }
 
+  fileprivate init(_ key: String) where Value == Date {
+    @Dependency(\.defaultAppStorage) var store
+    self.lookup = CastableLookup()
+    self.key = key
+    self.store = UncheckedSendable(store)
+  }
+
   fileprivate init(_ key: String) where Value == Data {
     @Dependency(\.defaultAppStorage) var store
     self.lookup = CastableLookup()
@@ -254,6 +279,13 @@ public struct AppStorageKey<Value: Sendable>: Sendable {
     self.store = UncheckedSendable(store)
   }
 
+  fileprivate init(_ key: String) where Value == Date? {
+    @Dependency(\.defaultAppStorage) var store
+    self.lookup = OptionalLookup(base: CastableLookup())
+    self.key = key
+    self.store = UncheckedSendable(store)
+  }
+
   fileprivate init(_ key: String) where Value == Data? {
     @Dependency(\.defaultAppStorage) var store
     self.lookup = OptionalLookup(base: CastableLookup())

Tests/ComposableArchitectureTests/AppStorageTests.swift

@@ -51,6 +51,38 @@ final class AppStorageTests: XCTestCase {
     XCTAssertEqual(defaults.url(forKey: "url"), URL(string: "https://example.com"))
   }
 
+  func testDefaultsReadDate() {
+    let expectedDate = Date()
+    @Dependency(\.defaultAppStorage) var defaults
+    defaults.set(expectedDate, forKey: "date")
+    @Shared(.appStorage("date")) var date: Date?
+    XCTAssertEqual(date, expectedDate)
+  }
+
+  func testDefaultsRegistered_Date() {
+    let expectedDate = Date()
+    @Dependency(\.defaultAppStorage) var defaults
+    @Shared(.appStorage("date")) var date: Date = expectedDate
+    XCTAssertEqual(defaults.object(forKey: "date") as? Date, expectedDate)
+
+    let newDate = Date().addingTimeInterval(60)
+    date = newDate
+    XCTAssertEqual(date, newDate)
+    XCTAssertEqual(defaults.object(forKey: "date") as? Date, newDate)
+  }
+
+  func testDefaultsRegistered_Optional_Date() {
+    let initialDate: Date? = Date()
+    @Dependency(\.defaultAppStorage) var defaults
+    @Shared(.appStorage("date")) var date: Date? = initialDate
+    XCTAssertEqual(defaults.object(forKey: "date") as? Date, initialDate)
+
+    let newDate = Date().addingTimeInterval(60)
+    date = newDate
+    XCTAssertEqual(date, newDate)
+    XCTAssertEqual(defaults.object(forKey: "date") as? Date, newDate)
+  }
+
   func testDefaultsRegistered_Optional() {
     @Dependency(\.defaultAppStorage) var defaults
     @Shared(.appStorage("data")) var data: Data?
@@ -184,6 +216,13 @@ final class AppStorageTests: XCTestCase {
     XCTAssertEqual(url2, nil)
   }
 
+  func testOptionalInitializers_Date() {
+    @Shared(.appStorage("date1")) var date1: Date?
+    XCTAssertEqual(date1, nil)
+    @Shared(.appStorage("date2")) var date2: Date? = nil
+    XCTAssertEqual(date2, nil)
+  }
+
   func testRemoveDuplicates() {
     @Dependency(\.defaultAppStorage) var store
     @Shared(.appStorage("count")) var count = 0