Localizable Alerts and Action Sheets

Examples/CaseStudies/SwiftUICaseStudies/04-HigherOrderReducers-ReusableFavoriting.swift

@@ -78,7 +78,7 @@ extension Reducer {
             .cancellable(id: FavoriteCancelId(id: state.id), cancelInFlight: true)
 
         case let .response(.failure(error)):
-          state.alert = .init(title: error.localizedDescription)
+          state.alert = .init(title: .init(error.localizedDescription))
           return .none
 
         case let .response(.success(isFavorite)):

Examples/TicTacToe/Sources/Core/LoginCore.swift

@@ -72,7 +72,7 @@ public let loginReducer =
         return .none
 
       case let .loginResponse(.failure(error)):
-        state.alert = .init(title: error.localizedDescription)
+        state.alert = .init(title: .init(error.localizedDescription))
         state.isLoginRequestInFlight = false
         return .none
 

Examples/TicTacToe/Sources/Core/TwoFactorCore.swift

@@ -58,7 +58,7 @@ public let twoFactorReducer = Reducer<TwoFactorState, TwoFactorAction, TwoFactor
       .map(TwoFactorAction.twoFactorResponse)
 
   case let .twoFactorResponse(.failure(error)):
-    state.alert = .init(title: error.localizedDescription)
+    state.alert = .init(title: .init(error.localizedDescription))
     state.isTwoFactorRequestInFlight = false
     return .none
 

Examples/TicTacToe/Sources/Views-UIKit/LoginViewController.swift

@@ -137,7 +137,7 @@ class LoginViewController: UIViewController {
         guard let alert = alert else { return }
 
         let alertController = UIAlertController(
-          title: alert.title, message: nil, preferredStyle: .alert)
+          title: alert.title.formatted(), message: nil, preferredStyle: .alert)
         alertController.addAction(
           UIAlertAction(
             title: "Ok", style: .default,

Examples/TicTacToe/Sources/Views-UIKit/TwoFactorViewController.swift

@@ -93,7 +93,7 @@ public final class TwoFactorViewController: UIViewController {
         guard let alert = alert else { return }
 
         let alertController = UIAlertController(
-          title: alert.title, message: nil, preferredStyle: .alert)
+          title: alert.title.formatted(), message: nil, preferredStyle: .alert)
         alertController.addAction(
           UIAlertAction(
             title: "Ok", style: .default,

Examples/TicTacToe/Tests/LoginSwiftUITests.swift

@@ -119,8 +119,7 @@ class LoginSwiftUITests: XCTestCase {
         self.scheduler.advance()
       },
       .receive(.loginResponse(.failure(.invalidUserPassword))) {
-        $0.alert = .init(
-          title: AuthenticationError.invalidUserPassword.localizedDescription)
+        $0.alert = .init(title: .init(AuthenticationError.invalidUserPassword.localizedDescription))
         $0.isActivityIndicatorVisible = false
         $0.isFormDisabled = false
       },

Examples/TicTacToe/Tests/TwoFactorSwiftUITests.swift

@@ -88,7 +88,7 @@ class TwoFactorSwiftUITests: XCTestCase {
         self.scheduler.advance()
       },
       .receive(.twoFactorResponse(.failure(.invalidTwoFactor))) {
-        $0.alert = .init(title: AuthenticationError.invalidTwoFactor.localizedDescription)
+        $0.alert = .init(title: .init(AuthenticationError.invalidTwoFactor.localizedDescription))
         $0.isActivityIndicatorVisible = false
         $0.isFormDisabled = false
       },

Sources/ComposableArchitecture/Internal/LocalizedStringKey.swift

@@ -0,0 +1,29 @@
+import SwiftUI
+
+extension LocalizedStringKey: CustomDebugOutputConvertible {
+  // NB: `LocalizedStringKey` conforms to `Equatable` but returns false for equivalent format strings.
+  public func formatted(locale: Locale? = nil) -> String {
+    let children = Array(Mirror(reflecting: self).children)
+    let key = children[0].value as! String
+    let arguments: [CVarArg] = Array(Mirror(reflecting: children[2].value).children)
+      .compactMap {
+        let children = Array(Mirror(reflecting: $0.value).children)
+        let value: Any
+        let formatter: Formatter?
+        // `LocalizedStringKey.FormatArgument` differs depending on OS/platform.
+        if children[0].label == "storage" {
+          (value, formatter) = Array(Mirror(reflecting: children[0].value).children)[0].value as! (Any, Formatter?)
+        } else {
+          value = children[0].value
+          formatter = children[1].value as? Formatter
+        }
+        return formatter?.string(for: value) ?? value as! CVarArg
+      }
+
+    return String(format: key, locale: nil, arguments: arguments)
+  }
+
+  public var debugOutput: String {
+    self.formatted().debugDescription
+  }
+}

Sources/ComposableArchitecture/SwiftUI/ActionSheet.swift

@@ -4,7 +4,7 @@ import SwiftUI
 /// `Action` generic is the type of actions that can be sent from tapping on a button in the sheet.
 ///
 /// This type can be used in your application's state in order to control the presentation or
-/// dismissal of action sheets. It is preferrable to use this API instead of the default SwiftUI API
+/// dismissal of action sheets. It is preferable to use this API instead of the default SwiftUI API
 /// for action sheets because SwiftUI uses 2-way bindings in order to control the showing and
 /// dismissal of sheets, and that does not play nicely with the Composable Architecture. The library
 /// requires that all state mutations happen by sending an action so that a reducer can handle that
@@ -107,12 +107,12 @@ import SwiftUI
 public struct ActionSheetState<Action> {
   public let id = UUID()
   public var buttons: [Button]
-  public var message: String?
-  public var title: String
+  public var message: LocalizedStringKey?
+  public var title: LocalizedStringKey
 
   public init(
-    title: String,
-    message: String? = nil,
+    title: LocalizedStringKey,
+    message: LocalizedStringKey? = nil,
     buttons: [Button]
   ) {
     self.buttons = buttons
@@ -146,8 +146,8 @@ extension ActionSheetState: CustomDebugOutputConvertible {
 @available(watchOS 6, *)
 extension ActionSheetState: Equatable where Action: Equatable {
   public static func == (lhs: Self, rhs: Self) -> Bool {
-    lhs.title == rhs.title
-      && lhs.message == rhs.message
+    lhs.title.formatted() == rhs.title.formatted()
+      && lhs.message?.formatted() == rhs.message?.formatted()
       && lhs.buttons == rhs.buttons
   }
 }
@@ -159,8 +159,8 @@ extension ActionSheetState: Equatable where Action: Equatable {
 @available(watchOS 6, *)
 extension ActionSheetState: Hashable where Action: Hashable {
   public func hash(into hasher: inout Hasher) {
-    hasher.combine(self.title)
-    hasher.combine(self.message)
+    hasher.combine(self.title.formatted())
+    hasher.combine(self.message?.formatted())
     hasher.combine(self.buttons)
   }
 }

Sources/ComposableArchitecture/SwiftUI/Alert.swift

@@ -4,7 +4,7 @@ import SwiftUI
 /// generic is the type of actions that can be sent from tapping on a button in the alert.
 ///
 /// This type can be used in your application's state in order to control the presentation or
-/// dismissal of alerts. It is preferrable to use this API instead of the default SwiftUI API
+/// dismissal of alerts. It is preferable to use this API instead of the default SwiftUI API
 /// for alerts because SwiftUI uses 2-way bindings in order to control the showing and dismissal
 /// of alerts, and that does not play nicely with the Composable Architecture. The library requires
 /// that all state mutations happen by sending an action so that a reducer can handle that logic,
@@ -92,14 +92,14 @@ import SwiftUI
 ///
 public struct AlertState<Action> {
   public let id = UUID()
-  public var message: String?
+  public var message: LocalizedStringKey?
   public var primaryButton: Button?
   public var secondaryButton: Button?
-  public var title: String
+  public var title: LocalizedStringKey
 
   public init(
-    title: String,
-    message: String? = nil,
+    title: LocalizedStringKey,
+    message: LocalizedStringKey? = nil,
     dismissButton: Button? = nil
   ) {
     self.title = title
@@ -108,8 +108,8 @@ public struct AlertState<Action> {
   }
 
   public init(
-    title: String,
-    message: String? = nil,
+    title: LocalizedStringKey,
+    message: LocalizedStringKey? = nil,
     primaryButton: Button,
     secondaryButton: Button
   ) {
@@ -124,7 +124,7 @@ public struct AlertState<Action> {
     public var type: `Type`
 
     public static func cancel(
-      _ label: String,
+      _ label: LocalizedStringKey,
       send action: Action? = nil
     ) -> Self {
       Self(action: action, type: .cancel(label: label))
@@ -137,23 +137,23 @@ public struct AlertState<Action> {
     }
 
     public static func `default`(
-      _ label: String,
+      _ label: LocalizedStringKey,
       send action: Action? = nil
     ) -> Self {
       Self(action: action, type: .default(label: label))
     }
 
     public static func destructive(
-      _ label: String,
+      _ label: LocalizedStringKey,
       send action: Action? = nil
     ) -> Self {
       Self(action: action, type: .destructive(label: label))
     }
 
-    public enum `Type`: Hashable {
-      case cancel(label: String?)
-      case `default`(label: String)
-      case destructive(label: String)
+    public enum `Type` {
+      case cancel(label: LocalizedStringKey?)
+      case `default`(label: LocalizedStringKey)
+      case destructive(label: LocalizedStringKey)
     }
   }
 }
@@ -194,24 +194,56 @@ extension AlertState: CustomDebugOutputConvertible {
 
 extension AlertState: Equatable where Action: Equatable {
   public static func == (lhs: Self, rhs: Self) -> Bool {
-    lhs.title == rhs.title
-      && lhs.message == rhs.message
+    lhs.title.formatted() == rhs.title.formatted()
+      && lhs.message?.formatted() == rhs.message?.formatted()
       && lhs.primaryButton == rhs.primaryButton
       && lhs.secondaryButton == rhs.secondaryButton
   }
 }
 extension AlertState: Hashable where Action: Hashable {
   public func hash(into hasher: inout Hasher) {
-    hasher.combine(self.title)
-    hasher.combine(self.message)
+    hasher.combine(self.title.formatted())
+    hasher.combine(self.message?.formatted())
     hasher.combine(self.primaryButton)
     hasher.combine(self.secondaryButton)
   }
 }
 extension AlertState: Identifiable {}
 
-extension AlertState.Button: Equatable where Action: Equatable {}
-extension AlertState.Button: Hashable where Action: Hashable {}
+extension AlertState.Button.`Type`: Equatable {
+  public static func == (lhs: Self, rhs: Self) -> Bool {
+    switch (lhs, rhs) {
+    case let (.cancel(lhs), .cancel(rhs)):
+      return lhs?.formatted() == rhs?.formatted()
+    case let (.default(lhs), .default(rhs)), let (.destructive(lhs), .destructive(rhs)):
+      return lhs.formatted() == rhs.formatted()
+    default:
+      return false
+    }
+  }
+}
+extension AlertState.Button: Equatable where Action: Equatable {
+  public static func == (lhs: Self, rhs: Self) -> Bool {
+    return lhs.action == rhs.action && lhs.type == rhs.type
+  }
+}
+
+extension AlertState.Button.`Type`: Hashable {
+  public func hash(into hasher: inout Hasher) {
+    switch self {
+    case let .cancel(label):
+      hasher.combine(label?.formatted())
+    case let .default(label), let .destructive(label):
+      hasher.combine(label.formatted())
+    }
+  }
+}
+extension AlertState.Button: Hashable where Action: Hashable {
+  public func hash(into hasher: inout Hasher) {
+    hasher.combine(self.action)
+    hasher.combine(self.type)
+  }
+}
 
 extension AlertState.Button {
   func toSwiftUI(send: @escaping (Action) -> Void) -> SwiftUI.Alert.Button {

Tests/ComposableArchitectureTests/LocalizedStringKeyTests.swift

@@ -0,0 +1,20 @@
+import SwiftUI
+import XCTest
+
+@testable import ComposableArchitecture
+
+class LocalizedStringKeyTests: XCTestCase {
+  func testFormatting() {
+    XCTAssertEqual(
+      LocalizedStringKey("Hello, #\(42)!").formatted(),
+      "Hello, #42!"
+    )
+
+    let formatter = NumberFormatter()
+    formatter.numberStyle = .ordinal
+    XCTAssertEqual(
+      LocalizedStringKey("You are \(1_000 as NSNumber, formatter: formatter) in line.").formatted(),
+      "You are 1,000th in line."
+    )
+  }
+}