swift 6 migration step 2

Author: janeshsutharios

SwiftUIExamples/SwiftUI-CommandLineTool/main.swift

@@ -185,3 +185,101 @@ await asyncExample()
 //        }
 //    }
 //}
+/**
+ In a multithreaded program, shared mutable state can lead to data races.
+ Swift `actor`s solve this by **serializing access** to their internal state — ensuring that only one task at a time can access or mutate it.
+
+ ### Actor Features
+
+ | Feature                  | Description                                                                 |
+ |--------------------------|-----------------------------------------------------------------------------|
+ | Reference Type           | ✅ Yes                                                                       |
+ | Thread-Safe by Default   | ✅ Yes – internal state is isolated and synchronized automatically           |
+ | Mutable State Isolation  | ✅ Yes – protects mutable properties from concurrent access                  |
+ | External Access          | ✅ Requires `await` for methods/properties that can suspend (`async`) calls |
+
+ Use `actor`s when you need to protect shared, mutable state in concurrent Swift code.
+ */
+
+
+actor Counter {
+    private var value = 0
+
+    func increment() {
+        value += 1
+    }
+
+    func get() -> Int {
+        return value
+    }
+    
+    // Sometimes you want an actor method that doesn’t need to access isolated state. Use nonisolated:
+    // No await needed to call it.
+    
+    nonisolated func logInfo(_ message: String) {
+        print("Info: \(message)")
+        
+    }
+}
+
+func counterExample() {
+    let counter = Counter()
+    Task {
+        await counter.increment()
+        print("Counter Value:", await counter.get()) // Prints 1
+    }
+    counter.logInfo("This is nonisolated")// No await needed to call it.
+}
+counterExample()
+/******************************/
+
+// Example of sendable
+struct UserSettings {
+    var theme: String = "Light"
+}
+
+func useInDetachedTask(settings: UserSettings) {
+    Task.detached {
+        print("Theme: \(settings.theme)")
+    }
+}
+// Note # actors & struct are already sendable by default. but classes are not Why? Because class instances can be shared mutable state, which isn't safe across threads.
+// Task.detached creates a new, independent concurrent task that runs outside the current actor context.
+
+
+// To silance warning use  @unchecked Sendable {Only do this if you are 100% sure: All properties are immutable OR You've synchronized access (e.g., with actors or locks)
+final class CarSettings: @unchecked Sendable {
+    let temprature: Int
+    init(temprature: Int) {
+        self.temprature = temprature
+    }
+}
+
+func useSafely(settings: CarSettings) {
+    Task.detached {
+        print("temprature: \(settings.temprature)")
+    }
+}
+
+// Making class as sendable
+final class MyLogger: Sendable {
+    let message: String
+
+    init(message: String) {
+        self.message = message
+    }
+}
+
+func detachTaskExample(logger: MyLogger) {
+    Task.detached {
+        print("message: \(logger.message)")
+    }
+}
+
+func exampleOfClassWithSendableProperties() {
+    let logger = MyLogger(message: "Hello World! from class Sendable detched task")
+    detachTaskExample(logger: logger)
+}
+exampleOfClassWithSendableProperties()
+// Use @concurrent to run on background thread. example fetchImage and decode image. for display Image use @mainactor
+// preconcurrency to silence the warning

SwiftUIExamples/SwiftUIExamples.xcodeproj/project.pbxproj

@@ -28,6 +28,7 @@
 		10AB45412DD24B7D00967614 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 10AB45402DD24B7D00967614 /* Assets.xcassets */; };
 		10AB45442DD24B7D00967614 /* Preview Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 10AB45432DD24B7D00967614 /* Preview Assets.xcassets */; };
 		10AB454B2DD257A100967614 /* BindingExample.swift in Sources */ = {isa = PBXBuildFile; fileRef = 10AB454A2DD257A100967614 /* BindingExample.swift */; };
+		4FB02AD62E3B3B320010B8D8 /* DependencyInjectionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4FB02AD52E3B3B320010B8D8 /* DependencyInjectionTests.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -77,6 +78,7 @@
 		10AB45402DD24B7D00967614 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		10AB45432DD24B7D00967614 /* Preview Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = "Preview Assets.xcassets"; sourceTree = "<group>"; };
 		10AB454A2DD257A100967614 /* BindingExample.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BindingExample.swift; sourceTree = "<group>"; };
+		4FB02AD52E3B3B320010B8D8 /* DependencyInjectionTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DependencyInjectionTests.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -135,6 +137,7 @@
 			isa = PBXGroup;
 			children = (
 				10525C742E2D2D1A00D7C510 /* git_hub_repos_async_tests.swift */,
+				4FB02AD52E3B3B320010B8D8 /* DependencyInjectionTests.swift */,
 				10525C7E2E2D2D9800D7C510 /* SwiftUIExamplesTests.swift */,
 			);
 			path = SwiftUIExamplesTests;
@@ -321,6 +324,7 @@
 			files = (
 				10525C7F2E2D2D9800D7C510 /* SwiftUIExamplesTests.swift in Sources */,
 				10525C852E2D2D9F00D7C510 /* git_hub_repos_async_tests.swift in Sources */,
+				4FB02AD62E3B3B320010B8D8 /* DependencyInjectionTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -560,6 +564,7 @@
 				INFOPLIST_KEY_UILaunchScreen_Generation = YES;
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPad = "UIInterfaceOrientationPortrait UIInterfaceOrientationPortraitUpsideDown UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPhone = "UIInterfaceOrientationPortrait UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
+				IPHONEOS_DEPLOYMENT_TARGET = 17.6;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -589,6 +594,7 @@
 				INFOPLIST_KEY_UILaunchScreen_Generation = YES;
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPad = "UIInterfaceOrientationPortrait UIInterfaceOrientationPortraitUpsideDown UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPhone = "UIInterfaceOrientationPortrait UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
+				IPHONEOS_DEPLOYMENT_TARGET = 17.6;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",

SwiftUIExamples/SwiftUIExamples/Archs/Dependency-Injection.swift

@@ -1,75 +1,64 @@
 import SwiftUI
 
-// MARK: - Protocol
+// MARK: - Repo Service Protocol
 
 protocol RepoServiceProtocol: Sendable {
-    //    func fetchRepos(completion: @escaping ([String]) -> Void)
-    // clouser replaced with async
     func fetchRepos() async -> [String]
 }
 
-// MARK: - Real Service
-
-final class RepoService: RepoServiceProtocol {
-    func fetchRepos() async -> [String] {
-        try? await Task.sleep(nanoseconds: 1_000_000_000) // Simulate 1 second delay
-        return ["Swift", "Combine", "UIKit", "CoreData"]
-    }
-}
-
-// MARK: - Mock Service (for previews or unit tests)
-
-final class MockRepoService: RepoServiceProtocol {
+struct MockRepoService: RepoServiceProtocol {
     func fetchRepos() async -> [String] {
+        try? await Task.sleep(nanoseconds: 500_000_000) // 0.5 sec
         return ["MockRepo1", "MockRepo2"]
     }
 }
 
-// MARK: - ViewModel
+// MARK: - Actor
 
-@MainActor
-final class RepoViewModel: ObservableObject {
-    @Published var repos: [String] = []
-    private let service: any RepoServiceProtocol
-    
-    init(service: any RepoServiceProtocol) {
+actor RepoActor {
+    private let service: RepoServiceProtocol
+
+    init(service: RepoServiceProtocol) {
         self.service = service
     }
-    
-    // fetchRepos() is nonisolated — it won’t run on MainActor.
-    nonisolated func loadRepos() async {
-        // This runs on background thread
-        let repos = await service.fetchRepos()
-        
-        // Switch to main actor for UI update
-        await setRepos(repos)
-    }
-    
-    private func setRepos(_ repos: [String]) {
-        self.repos = repos
+
+    func loadRepos() async -> [String] {
+        await service.fetchRepos()
     }
 }
 
 // MARK: - View
 
 struct ProjectsListView: View {
-    @StateObject var viewModel: RepoViewModel
-    
+    @State private var repos: [String] = []
+    private let repoActor: RepoActor
+
+    init(service: RepoServiceProtocol = MockRepoService()) {
+        self.repoActor = RepoActor(service: service)
+    }
+
     var body: some View {
         NavigationView {
-            List(viewModel.repos, id: \.self) { repo in
+            List(repos, id: \.self) { repo in
                 Text(repo)
             }
             .navigationTitle("Projects")
             .task {
-                await viewModel.loadRepos()
+                await fetchAndUpdate()
             }
         }
     }
+
+    private func fetchAndUpdate() async {
+        let result = await repoActor.loadRepos()
+        repos = result
+    }
 }
 
+// MARK: - Preview
+
 struct ProjectsListView_Previews: PreviewProvider {
     static var previews: some View {
-        ProjectsListView(viewModel: .init(service: MockRepoService()))
+        ProjectsListView()
     }
 }