Support Swift 6 language mode (#20)

# Support Swift 6 language mode

## ♻️ Current situation & Problem
SpeziChat currently does not support Swift 6 language mode with complete
concurrency checking.

Addresses #15

## ⚙️ Release Notes 
- Support Swift 6 language mode
- Lift dependencies
- Fix UI tests on iOS and macOS


## 📚 Documentation
Necessary workarounds regarding the MainActor documented


## ✅ Testing
--


## 📝 Code of Conduct & Contributing Guidelines 

By submitting creating this pull request, you agree to follow our [Code
of
Conduct](https://github.com/StanfordSpezi/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordSpezi/.github/blob/main/CONTRIBUTING.md):
- [x] I agree to follow the [Code of
Conduct](https://github.com/StanfordSpezi/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordSpezi/.github/blob/main/CONTRIBUTING.md).

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.9
+// swift-tools-version:6.0
 
 //
 // This source file is part of the Stanford Spezi open source project
@@ -23,9 +23,9 @@ let package = Package(
         .library(name: "SpeziChat", targets: ["SpeziChat"])
     ],
     dependencies: [
-        .package(url: "https://github.com/StanfordSpezi/SpeziFoundation", from: "2.0.0-beta.3"),
-        .package(url: "https://github.com/StanfordSpezi/SpeziSpeech", from: "1.0.1"),
-        .package(url: "https://github.com/StanfordSpezi/SpeziViews", from: "1.3.1")
+        .package(url: "https://github.com/StanfordSpezi/SpeziFoundation", from: "2.0.0"),
+        .package(url: "https://github.com/StanfordSpezi/SpeziSpeech", from: "1.1.1"),
+        .package(url: "https://github.com/StanfordSpezi/SpeziViews", from: "1.8.0")
     ],
     targets: [
         .target(

Sources/SpeziChat/ChatView+ShareSheet.swift

@@ -41,6 +41,7 @@ extension ChatView {
         func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {}
     }
     #else
+    @MainActor  // On non-macOS SDKs, `UIViewControllerRepresentable` enforces the `MainActor` isolation
     struct ShareSheet {
         let sharedItem: Data
         let sharedItemType: ChatExportFormat

Sources/SpeziChat/ChatView.swift

@@ -115,7 +115,19 @@ public struct ChatView: View {
                 MessageInputView($chat, messagePlaceholder: messagePlaceholder, speechToText: speechToText)
                     .disabled(disableInput)
                     .onPreferenceChange(MessageInputViewHeightKey.self) { newValue in
-                        messageInputHeight = newValue + 12
+                        // The `onPreferenceChange` view modfier now takes a `@Sendable` closure, therefore we cannot capture `@MainActor` isolated properties
+                        // on the `View` directly anymore: https://developer.apple.com/documentation/swiftui/view/onpreferencechange(_:perform:)?changes=latest_minor
+                        // However, as the `@Sendable` closure is still run on the MainActor (at least in my testing on 18.2 RC SDKs), we can use `MainActor.assumeIsolated`
+                        // to avoid scheduling a `MainActor` `Task`, which could delay execution and cause unexpected UI behavior
+                        if Thread.isMainThread {
+                            MainActor.assumeIsolated {
+                                messageInputHeight = newValue + 12
+                            }
+                        } else {
+                            Task { @MainActor in
+                                messageInputHeight = newValue + 12
+                            }
+                        }
                     }
             }
         }

Sources/SpeziChat/Helpers/MessageInputViewHeightKey.swift

@@ -12,7 +12,7 @@ import SwiftUI
 /// A SwiftUI `PreferenceKey` that is used by the ``MessageInputView`` to propagate the height of the view up the view hierarchy.
 public struct MessageInputViewHeightKey: PreferenceKey {
     /// Default height of 0.
-    public static var defaultValue: CGFloat = 0
+    public static let defaultValue: CGFloat = 0
 
 
     /// Writes the received value to the `PreferenceKey`.

Sources/SpeziChat/Models/ChatEntity+HiddenMessageType.swift

@@ -18,7 +18,7 @@ extension ChatEntity {
     ///     static let testType = HiddenMessageType(name: "testType")
     /// }
     /// ```
-    public struct HiddenMessageType: Codable, Equatable, Hashable {
+    public struct HiddenMessageType: Codable, Equatable, Hashable, Sendable {
         /// Default ``HiddenMessageType``.
         public static let unknown = HiddenMessageType(name: "unknown")
 

Tests/UITests/TestAppUITests/TestAppUITests.swift

@@ -40,10 +40,13 @@ class TestAppUITests: XCTestCase {
     }
 
     func testChatExport() throws {  // swiftlint:disable:this function_body_length
+        // Skip chat export test on visionOS and macOS
         #if os(visionOS)
         throw XCTSkip("VisionOS is unstable and are skipped at the moment")
+        #elseif os(macOS)
+        throw XCTSkip("macOS export to a file is not possible (regular sharesheet is)")
         #endif
-        
+
         let app = XCUIApplication()
         let filesApp = XCUIApplication(bundleIdentifier: "com.apple.DocumentsApp")
         let maxRetries = 10
@@ -78,7 +81,13 @@ class TestAppUITests: XCTestCase {
             #endif
 
             sleep(3)
-            XCTAssert(app.buttons["Save"].waitForExistence(timeout: 2))
+
+            // Select "On My iPhone / iPad" directory, if necessary
+            let predicate = NSPredicate(format: "label BEGINSWITH[c] %@", "On My")
+            let matchingStaticTexts = app.staticTexts.containing(predicate)
+            matchingStaticTexts.allElementsBoundByIndex.first?.tap()
+
+            XCTAssert(app.buttons["Save"].waitForExistence(timeout: 5))
             app.buttons["Save"].tap()
             sleep(10)    // Wait until file is saved
 
@@ -144,8 +153,12 @@ class TestAppUITests: XCTestCase {
         XCTAssert(app.staticTexts["SpeziChat"].waitForExistence(timeout: 1))
         XCTAssert(app.buttons["Speaker strikethrough"].waitForExistence(timeout: 2))
         XCTAssert(!app.buttons["Speaker"].waitForExistence(timeout: 2))
-
+
+        #if os(macOS)
+        app.buttons["Speaker strikethrough"].firstMatch.tap()   // on macOS, need to match for first speaker that is found
+        #else
         app.buttons["Speaker strikethrough"].tap()
+        #endif
 
         XCTAssert(!app.buttons["Speaker strikethrough"].waitForExistence(timeout: 2))
         XCTAssert(app.buttons["Speaker"].waitForExistence(timeout: 2))

Tests/UITests/UITests.xcodeproj/project.pbxproj

@@ -398,7 +398,7 @@
 				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_STRICT_CONCURRENCY = complete;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2,7";
 			};
 			name = Debug;
@@ -437,7 +437,7 @@
 				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_STRICT_CONCURRENCY = complete;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2,7";
 			};
 			name = Release;
@@ -584,7 +584,7 @@
 				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_STRICT_CONCURRENCY = complete;
-				SWIFT_VERSION = 5.0;
+				SWIFT_VERSION = 6.0;
 				TARGETED_DEVICE_FAMILY = "1,2,7";
 			};
 			name = Test;