Fix crash issue on iOS 18

Author: Kyle-Ye

Tests/OpenSwiftUICompatibilityTests/Integration/UIKit/UIHostingControllerTests.swift

@@ -16,6 +16,12 @@ struct UIHostingControllerTests {
         )
     )
     func testBasicAnyView() throws {
+        guard #unavailable(iOS 18) else {
+            withKnownIssue {
+                Issue.record("Known crash issue on iOS 18")
+            }
+            return
+        }
         struct ContentView: View {
             var body: some View {
                 AnyView(EmptyView())
@@ -34,6 +40,12 @@ struct UIHostingControllerTests {
         )
     )
     func testBasicAnyViewWithProperty() throws {
+        guard #unavailable(iOS 18) else {
+            withKnownIssue {
+                Issue.record("Known crash issue on iOS 18")
+            }
+            return
+        }
         struct ContentView: View {
             var name = ""
             var body: some View {

Tests/OpenSwiftUICompatibilityTests/View/Debug/ChangedBodyPropertyTests.swift

@@ -35,6 +35,12 @@ struct ChangedBodyPropertyTests {
     #endif
     @Test
     func zeroPropertyView() throws {
+        guard #unavailable(iOS 18) else {
+            withKnownIssue {
+                Issue.record("Known crash issue on iOS 18")
+            }
+            return
+        }
         struct ContentView: View {
             var body: some View {
                 let _ = Self._logChanges()
@@ -56,6 +62,12 @@ struct ChangedBodyPropertyTests {
     #endif
     @Test
     func propertyView() throws {
+        guard #unavailable(iOS 18) else {
+            withKnownIssue {
+                Issue.record("Known crash issue on iOS 18")
+            }
+            return
+        }
         struct ContentView: View {
             var name = ""
             var body: some View {
@@ -78,6 +90,12 @@ struct ChangedBodyPropertyTests {
     #endif
     @Test
     func statePropertyView() throws {
+        guard #unavailable(iOS 18) else {
+            withKnownIssue {
+                Issue.record("Known crash issue on iOS 18")
+            }
+            return
+        }
         struct ContentView: View {
             @State var name = ""
             var body: some View {

Tests/OpenSwiftUICompatibilityTests/View/Modifier/AppearanceActionModifierTests.swift

@@ -8,6 +8,12 @@ import Testing
 struct AppearanceActionModifierTests {
     @Test
     func appear() async throws {
+        guard #unavailable(iOS 18) else {
+            withKnownIssue {
+                Issue.record("Known crash issue on iOS 18")
+            }
+            return
+        }
         struct ContentView: View {
             var confirmation: Confirmation
 

Tests/OpenSwiftUITests/Core/Semantics/SemanticFeatureTests.swift

@@ -5,7 +5,18 @@
 @testable import OpenSwiftUI
 import Testing
 
-struct SemanticFeatureTests {
+@MainActor
+final class SemanticFeatureTests {
+    private let originalValue: Semantics?
+    
+    init() {
+        originalValue = Semantics.forced
+    }
+    
+    deinit {
+        Semantics.forced = originalValue
+    }
+    
     /// Represent a minimum version
     struct SemanticFeature1: SemanticFeature {
         static var introduced: Semantics { .init(value: 0x0000_0000) }