[V5] Use Swift 6 with complete concurrency checking (#3759)

Author: laevandus

.github/workflows/smoke-checks.yml

@@ -64,8 +64,9 @@ jobs:
 
   build-old-xcode:
     name: Build LLC + UI (Xcode 15)
-    runs-on: macos-14
-    if: ${{ github.event.inputs.record_snapshots != 'true' }}
+    runs-on: macos-15
+    # if: ${{ github.event.inputs.record_snapshots != 'true' }}
+    if: false # disable Xcode 15 builds
     env:
       XCODE_VERSION: "15.4"
     steps:

.swiftformat

@@ -1,6 +1,6 @@
 # Stream rules
 --header "\nCopyright © {year} Stream.io Inc. All rights reserved.\n"
---swiftversion 5.6
+--swiftversion 6.0
 
 --ifdef no-indent
 --disable redundantType

DemoApp/Extensions/UserDefaults+Shared.swift

@@ -5,7 +5,7 @@
 import Foundation
 
 extension UserDefaults {
-    static let shared = UserDefaults(suiteName: applicationGroupIdentifier)!
+    static var shared: UserDefaults { UserDefaults(suiteName: applicationGroupIdentifier)! }
 
     var currentUserId: String? {
         get { string(forKey: #function) }

DemoApp/Screens/AppConfigViewController/AppConfigViewController.swift

@@ -37,11 +37,11 @@ struct DemoAppConfig {
     }
 }
 
-class AppConfig {
+class AppConfig: @unchecked Sendable {
     /// The Demo App Configuration.
     var demoAppConfig: DemoAppConfig
 
-    static var shared = AppConfig()
+    static let shared = AppConfig()
 
     private init() {
         // Default DemoAppConfig
@@ -69,13 +69,13 @@ class AppConfig {
     }
 }
 
-class UserConfig {
+class UserConfig: @unchecked Sendable {
     var isInvisible = false
     var language: TranslationLanguage?
     var typingIndicatorsEnabled: Bool?
     var readReceiptsEnabled: Bool?
 
-    static var shared = UserConfig()
+    static let shared = UserConfig()
 
     private init() {}
 }

DemoApp/Screens/Livestream/DemoLivestreamChatChannelVC.swift

@@ -456,7 +456,7 @@ class DemoLivestreamComposerVC: ComposerVC {
         from url: URL,
         type: AttachmentType,
         info: [LocalAttachmentInfoKey: Any],
-        extraData: (any Encodable)?
+        extraData: (Encodable & Sendable)?
     ) throws {
         guard let cid = livestreamChannelController?.channel?.cid else {
             return

DemoApp/Screens/Livestream/DemoLivestreamMessageActionsVC.swift

@@ -7,7 +7,7 @@ import StreamChatUI
 import UIKit
 
 /// Delegate protocol for `LivestreamMessageActionsVC`
-protocol LivestreamMessageActionsVCDelegate: AnyObject {
+@MainActor protocol LivestreamMessageActionsVCDelegate: AnyObject {
     func livestreamMessageActionsVC(
         _ vc: DemoLivestreamMessageActionsVC,
         message: ChatMessage,

DemoApp/Screens/UserProfileViewController.swift

@@ -150,9 +150,7 @@ class UserProfileViewController: UITableViewController, CurrentChatUserControlle
         let unreadDetailsView = UnreadDetailsView(
             onLoadData: { [weak self](completion: @escaping (Result<CurrentUserUnreads, Error>) -> Void) in
                 self?.currentUserController.loadAllUnreads { result in
-                    DispatchQueue.main.async {
-                        completion(result)
-                    }
+                    completion(result)
                 }
             },
             onDismiss: { [weak self] in

DemoApp/Shared/DemoAppCoordinator.swift

@@ -6,7 +6,7 @@ import StreamChat
 import StreamChatUI
 import UIKit
 
-final class DemoAppCoordinator: NSObject {
+@MainActor final class DemoAppCoordinator: NSObject {
     internal let window: UIWindow
     internal let pushNotifications: PushNotifications
 

DemoApp/Shared/DemoUsers.swift

@@ -5,7 +5,7 @@
 import Foundation
 import StreamChat
 
-var apiKeyString = ProcessInfo.processInfo.environment["CUSTOM_API_KEY"] ?? DemoApiKeys.frankfurtC1.rawValue
+nonisolated(unsafe) var apiKeyString = ProcessInfo.processInfo.environment["CUSTOM_API_KEY"] ?? DemoApiKeys.frankfurtC1.rawValue
 let applicationGroupIdentifier = "group.io.getstream.iOS.ChatDemoApp"
 
 enum DemoUserType {

DemoApp/Shared/StreamChatWrapper.swift

@@ -8,7 +8,7 @@ import StreamChatUI
 import UIKit
 import UserNotifications
 
-final class StreamChatWrapper {
+@MainActor final class StreamChatWrapper {
     static var shared = StreamChatWrapper(apiKeyString: apiKeyString)
 
     static func replaceSharedInstance(apiKeyString: String) {
@@ -61,7 +61,7 @@ extension StreamChatWrapper {
 // MARK: User Authentication
 
 extension StreamChatWrapper {
-    func connect(user: DemoUserType, completion: @escaping (Error?) -> Void) {
+    func connect(user: DemoUserType, completion: @escaping @MainActor(Error?) -> Void) {
         switch user {
         case let .credentials(userCredentials):
             connectUser(credentials: userCredentials, completion: completion)
@@ -74,7 +74,7 @@ extension StreamChatWrapper {
         }
     }
 
-    func connectUser(credentials: UserCredentials?, completion: @escaping (Error?) -> Void) {
+    func connectUser(credentials: UserCredentials?, completion: @escaping @MainActor(Error?) -> Void) {
         guard let userCredentials = credentials else {
             log.error("User credentials are missing")
             return
@@ -121,7 +121,7 @@ extension StreamChatWrapper {
         )
     }
 
-    func logIn(as user: DemoUserType, completion: @escaping (Error?) -> Void) {
+    func logIn(as user: DemoUserType, completion: @escaping @MainActor(Error?) -> Void) {
         // Setup Stream Chat
         setUpChat()
 
@@ -134,14 +134,11 @@ extension StreamChatWrapper {
             } else {
                 StreamChatWrapper.onRemotePushRegistration?()
             }
-
-            DispatchQueue.main.async {
-                completion(error)
-            }
+            completion(error)
         }
     }
 
-    func logOut(completion: @escaping () -> Void) {
+    func logOut(completion: @escaping @MainActor() -> Void) {
         guard let client = self.client else {
             logClientNotInstantiated()
             return
@@ -192,7 +189,7 @@ extension StreamChatWrapper {
 // An object to test the Stream Models transformer.
 // By default it is not used. To use it, set it to the `modelsTransformer` property of the `ChatClientConfig`.
 
-class CustomStreamModelsTransformer: StreamModelsTransformer {
+final class CustomStreamModelsTransformer: StreamModelsTransformer {
     func transform(channel: ChatChannel) -> ChatChannel {
         channel.replacing(
             name: "Custom Name",