Swift 6: complete concurrency checking (LLC and UIKit)

.github/workflows/smoke-checks.yml

@@ -68,7 +68,8 @@ jobs:
   build-old-xcode:
     name: Build LLC + UI (Xcode 15)
     runs-on: macos-15
-    if: ${{ github.event.inputs.record_snapshots != 'true' }}
+    # 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/Screens/Create Chat/CreateChatViewController.swift

@@ -25,19 +25,21 @@ class CreateChatViewController: UIViewController {
 
             // Create the Channel on backend
             controller.synchronize { [weak self] error in
-                if let error = error {
-                    self?.presentAlert(title: "Error when creating the channel", message: error.localizedDescription)
-                    return
+                Task { @MainActor in
+                    if let error = error {
+                        self?.presentAlert(title: "Error when creating the channel", message: error.localizedDescription)
+                        return
+                    }
+
+                    // Send the message
+                    createMessage(text)
+
+                    // Present the new chat and controller
+                    let vc = ChatChannelVC()
+                    vc.channelController = controller
+
+                    navController.setViewControllers([navController.viewControllers.first!, vc], animated: true)
                 }
-
-                // Send the message
-                createMessage(text)
-
-                // Present the new chat and controller
-                let vc = ChatChannelVC()
-                vc.channelController = controller
-
-                navController.setViewControllers([navController.viewControllers.first!, vc], animated: true)
             }
         }
     }
@@ -143,9 +145,11 @@ class CreateChatViewController: UIViewController {
         ])
 
         // Empty initial search to get all users
-        searchController.search(term: nil) { error in
+        searchController.search(term: nil) { [weak self] error in
             if error != nil {
-                self.update(for: .error)
+                Task { @MainActor in
+                    self?.update(for: .error)
+                }
             }
         }
         infoLabel.text = "On the platform"
@@ -235,9 +239,11 @@ class CreateChatViewController: UIViewController {
 
         operation?.cancel()
         operation = DispatchWorkItem { [weak self] in
-            self?.searchController.search(term: sender.text) { error in
+            self?.searchController.search(term: sender.text) { [weak self] error in
                 if error != nil {
-                    self?.update(for: .error)
+                    Task { @MainActor in
+                        self?.update(for: .error)
+                    }
                 }
             }
         }

DemoApp/Screens/Create Chat/NameGroupViewController.swift

@@ -131,11 +131,13 @@ class NameGroupViewController: UIViewController {
                 name: name,
                 members: Set(selectedUsers.map(\.id))
             )
-            channelController?.synchronize { error in
-                if let error = error {
-                    self.presentAlert(title: "Error when creating the channel", message: error.localizedDescription)
-                } else {
-                    self.navigationController?.popToRootViewController(animated: true)
+            channelController?.synchronize { [weak self] error in
+                Task { @MainActor in
+                    if let error = error {
+                        self?.presentAlert(title: "Error when creating the channel", message: error.localizedDescription)
+                    } else {
+                        self?.navigationController?.popToRootViewController(animated: true)
+                    }
                 }
             }
         } catch {

DemoApp/Screens/DemoDraftMessageListVC.swift

@@ -94,7 +94,9 @@ class DemoDraftMessageListVC: UIViewController, ThemeProvider {
         currentUserController.delegate = self
         loadingIndicator.startAnimating()
         currentUserController.loadDraftMessages { [weak self] _ in
-            self?.loadingIndicator.stopAnimating()
+            Task { @MainActor in
+                self?.loadingIndicator.stopAnimating()
+            }
         }
     }
 
@@ -105,7 +107,9 @@ class DemoDraftMessageListVC: UIViewController, ThemeProvider {
 
         isPaginatingDrafts = true
         currentUserController.loadMoreDraftMessages { [weak self] _ in
-            self?.isPaginatingDrafts = false
+            Task { @MainActor in
+                self?.isPaginatingDrafts = false
+            }
         }
     }
 

DemoApp/Screens/MembersViewController.swift

@@ -37,7 +37,9 @@ class MembersViewController: UITableViewController, ChatChannelMemberListControl
 
     private func synchronizeAndUpdateData() {
         membersController.synchronize { [weak self] _ in
-            self?.updateData()
+            Task { @MainActor in
+                self?.updateData()
+            }
         }
     }
 

DemoApp/Shared/StreamChatWrapper.swift

@@ -8,7 +8,7 @@ import StreamChatUI
 import UIKit
 import UserNotifications
 
-final class StreamChatWrapper {
+final class StreamChatWrapper: @unchecked Sendable {
     static var shared = StreamChatWrapper(apiKeyString: apiKeyString)
 
     static func replaceSharedInstance(apiKeyString: String) {
@@ -56,7 +56,7 @@ extension StreamChatWrapper {
 // MARK: User Authentication
 
 extension StreamChatWrapper {
-    func connect(user: DemoUserType, completion: @escaping (Error?) -> Void) {
+    func connect(user: DemoUserType, completion: @escaping @Sendable(Error?) -> Void) {
         switch user {
         case let .credentials(userCredentials):
             connectUser(credentials: userCredentials, completion: completion)
@@ -69,7 +69,7 @@ extension StreamChatWrapper {
         }
     }
 
-    func connectUser(credentials: UserCredentials?, completion: @escaping (Error?) -> Void) {
+    func connectUser(credentials: UserCredentials?, completion: @escaping @Sendable(Error?) -> Void) {
         guard let userCredentials = credentials else {
             log.error("User credentials are missing")
             return
@@ -187,7 +187,7 @@ 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",