feat(hosting): track foreign subviews and report unsupported additions

Sources/COpenSwiftUI/Util/AppleInternal.c

@@ -0,0 +1,29 @@
+//
+//  AppleInternal.c
+//  COpenSwiftUI
+//
+//  Audited for 6.5.4
+//  Status: Complete
+
+#include "AppleInternal.h"
+
+#if OPENSWIFTUI_TARGET_OS_DARWIN
+#include <dispatch/dispatch.h>
+
+extern bool os_variant_allows_internal_security_policies(const char *subsystem);
+extern bool os_variant_has_internal_content(const char *subsystem);
+#endif
+
+bool _OpenSwiftUIIsAppleInternalBuild(void) {
+    #if OPENSWIFTUI_TARGET_OS_DARWIN
+    static bool isInternal;
+    static dispatch_once_t once;
+    dispatch_once(&once, ^{
+        isInternal = os_variant_allows_internal_security_policies("org.OpenSwiftUIProject.OpenSwiftUI")
+            && os_variant_has_internal_content("org.OpenSwiftUIProject.OpenSwiftUI");
+    });
+    return isInternal;
+    #else
+    return false;
+    #endif
+}

Sources/COpenSwiftUI/Util/AppleInternal.h

@@ -0,0 +1,20 @@
+//
+//  AppleInternal.h
+//  COpenSwiftUI
+//
+//  Audited for 6.5.4
+//  Status: Complete
+
+#ifndef AppleInternal_h
+#define AppleInternal_h
+
+#include "OpenSwiftUIBase.h"
+
+OPENSWIFTUI_EXTERN_C_BEGIN
+
+OPENSWIFTUI_EXPORT
+bool _OpenSwiftUIIsAppleInternalBuild(void);
+
+OPENSWIFTUI_EXTERN_C_END
+
+#endif /* AppleInternal_h */

Sources/OpenSwiftUI/Integration/Hosting/AppKit/View/NSHostingView.swift

@@ -539,6 +539,34 @@ open class NSHostingView<Content>: NSView, XcodeViewDebugDataProvider where Cont
 
     private var isInsertingRenderedSubview: Bool = false
 
+    // Audited for 6.5.4
+    override dynamic open func didAddSubview(_ subview: NSView) {
+        super.didAddSubview(subview)
+        guard !isInsertingRenderedSubview else { return }
+        foreignSubviews.add(subview)
+        if isLinkedOnOrAfter(.v7) {
+            let hostName = if viewController == nil {
+                "NSHostingView"
+            } else {
+                "NSHostingController.view"
+            }
+            Log.runtimeIssues(
+                "Adding '%s' as a subview of %s is not supported and may result in a broken view hierarchy. Add your view above %s in a common superview or insert it into your OpenSwiftUI content in a NSViewRepresentable instead.",
+                [
+                    "\(type(of: subview))",
+                    hostName,
+                    hostName,
+                ]
+            )
+        }
+    }
+
+    // Audited for 6.5.4
+    override dynamic open func willRemoveSubview(_ subview: NSView) {
+        super.willRemoveSubview(subview)
+        foreignSubviews.remove(subview)
+    }
+
     private var sizeConstraints: SizeConstraints?
 
     private struct SizeConstraints {

Sources/OpenSwiftUI/Integration/Hosting/UIKit/View/UIHostingView.swift

@@ -413,9 +413,38 @@ open class _UIHostingView<Content>: UIView, XcodeViewDebugDataProvider where Con
         }
     }
 
-    private lazy var foreignSubviews: NSHashTable<UIView>? = NSHashTable.weakObjects()
+    private lazy var foreignSubviews: NSHashTable<UIView> = NSHashTable.weakObjects()
 
     private var isInsertingRenderedSubview: Bool = false
+
+    // Audited for 6.5.4
+    override dynamic open func didAddSubview(_ subview: UIView) {
+        super.didAddSubview(subview)
+        guard !isInsertingRenderedSubview else { return }
+        foreignSubviews.add(subview)
+        if isLinkedOnOrAfter(.v7) {
+            let hostName = if _OpenSwiftUIIsAppleInternalBuild(), viewController == nil {
+                "_UIHostingView"
+            } else {
+                "UIHostingController.view"
+            }
+            Log.runtimeIssues(
+                "Adding '%s' as a subview of %s is not supported and may result in a broken view hierarchy. Add your view above %s in a common superview or insert it into your OpenSwiftUI content in a UIViewRepresentable instead.",
+                [
+                    "\(type(of: subview))",
+                    hostName,
+                    hostName,
+                ]
+            )
+        }
+    }
+
+    // Audited for 6.5.4
+    override dynamic open func willRemoveSubview(_ subview: UIView) {
+        super.willRemoveSubview(subview)
+        foreignSubviews.remove(subview)
+    }
+
 
     /// The UIKit notion of the safe area insets.
     open override var safeAreaInsets: UIEdgeInsets {
@@ -486,8 +515,12 @@ open class _UIHostingView<Content>: UIView, XcodeViewDebugDataProvider where Con
         }
     }
 
-    @objc(swiftui_insertRenderedSubview:atIndex:) // FIXME: ViewUpdater -> CoreViewAddSubview
-    private func openswiftui_insertRenderedSubview(_ view: UIView, at index: Int) {
+    @_spi(ForOpenSwiftUIOnly)
+    #if OPENSWIFTUI_SWIFTUI_RENDERER
+    @objc(swiftui_insertRenderedSubview:atIndex:)
+    #endif
+    override public func openswiftui_insertRenderedSubview(_ subview: Any, at index: Int) {
+        let view = subview as! UIView
         isInsertingRenderedSubview = true
         insertSubview(view, at: index)
         isInsertingRenderedSubview = false

Sources/OpenSwiftUICore/Log/Logging.swift

@@ -193,11 +193,7 @@ package enum Log {
         #if OPENSWIFTUI_LINK_TESTING
         if Test.current != nil {
             let comment: Comment = #"[Runtime Issue] message: \#(message.description) args: \#(args)"#
-            #if swift(>=6.3)
             Issue.record(comment, severity: .warning)
-            #else
-            Issue.record(comment)
-            #endif
         }
         #endif
 

Tests/OpenSwiftUICoreTests/Testing/RuntimeIssueHandlingTrait.swift → Sources/OpenSwiftUITestsSupport/Testing/RuntimeIssueHandlingTrait.swift

@@ -1,20 +1,20 @@
 //
 //  RuntimeIssueHandlingTrait.swift
-//  OpenSwiftUICoreTests
+//  OpenSwiftUITestsSupport
 
 import Foundation
-import Testing
+package import Testing
 
-func containsRuntimeIssue(_ message: String) -> ContainsRuntimeIssueTrait {
+package func containsRuntimeIssue(_ message: String) -> ContainsRuntimeIssueTrait {
     ContainsRuntimeIssueTrait(message: message)
 }
 
-struct ContainsRuntimeIssueTrait: TestTrait, TestScoping {
-    typealias TestScopeProvider = ContainsRuntimeIssueTrait
+package struct ContainsRuntimeIssueTrait: TestTrait, TestScoping {
+    package typealias TestScopeProvider = ContainsRuntimeIssueTrait
 
     var message: String
 
-    func provideScope(
+    package func provideScope(
         for test: Test,
         testCase: Test.Case?,
         performing function: @Sendable () async throws -> Void
@@ -29,12 +29,16 @@ struct ContainsRuntimeIssueTrait: TestTrait, TestScoping {
             }
         }
         try await issueHandler.provideScope(for: test, testCase: testCase, performing: function)
+        #if !OPENSWIFTUI_LINK_TESTING
+        Issue.record("ContainsRuntimeIssueTrait requires OPENSWIFTUI_LINK_TESTING to be set", severity: .warning)
+        #else
         if !state.hasMatch {
             Issue.record(
                 #"Expected runtime issue was not recorded: "\#(message)""#,
                 sourceLocation: test.sourceLocation
             )
         }
+        #endif
     }
 }
 

Tests/OpenSwiftUICoreTests/Data/DynamicProperty/DynamicPropertyCacheTests.swift

@@ -4,6 +4,7 @@
 
 import OpenAttributeGraphShims
 @testable import OpenSwiftUICore
+import OpenSwiftUITestsSupport
 import Testing
 
 // FIXME: Remove after we implement forEachField

Tests/OpenSwiftUICoreTests/Data/State/StoredLocationTests.swift

@@ -5,6 +5,7 @@
 import Foundation
 import OpenAttributeGraphShims
 @_spi(ForOpenSwiftUIOnly) @testable import OpenSwiftUICore
+import OpenSwiftUITestsSupport
 import Testing
 
 @MainActor

Tests/OpenSwiftUICoreTests/Util/MainActorUtilsTests.swift

@@ -3,6 +3,7 @@
 //  OpenSwiftUICoreTests
 
 import OpenSwiftUICore
+import OpenSwiftUITestsSupport
 import Testing
 
 struct MainActorUtilsTests {

Tests/OpenSwiftUITests/Integration/Hosting/AppKit/View/NSHostingViewTests.swift

@@ -0,0 +1,26 @@
+//
+//  NSHostingViewTests.swift
+//  OpenSwiftUITests
+
+#if os(macOS)
+import AppKit
+import OpenSwiftUI
+import OpenSwiftUICore
+import OpenSwiftUITestsSupport
+import Testing
+
+@MainActor
+struct NSHostingViewTests {
+    @Test(containsRuntimeIssue("Adding '%s' as a subview of %s is not supported and may result in a broken view hierarchy. Add your view above %s in a common superview or insert it into your OpenSwiftUI content in a NSViewRepresentable instead."))
+    func didAddSubviewRecordsRuntimeIssue() {
+        let hostingView = NSHostingView(rootView: EmptyView())
+        let subview = NSView()
+
+        Semantics.v7.test {
+            hostingView.addSubview(subview)
+        }
+
+        #expect(subview.superview === hostingView)
+    }
+}
+#endif

Tests/OpenSwiftUITests/Integration/Hosting/UIKit/View/UIHostingViewTests.swift

@@ -0,0 +1,26 @@
+//
+//  UIHostingViewTests.swift
+//  OpenSwiftUITests
+
+#if os(iOS) || os(visionOS)
+import OpenSwiftUI
+import OpenSwiftUICore
+import OpenSwiftUITestsSupport
+import Testing
+import UIKit
+
+@MainActor
+struct UIHostingViewTests {
+    @Test(containsRuntimeIssue("Adding '%s' as a subview of %s is not supported and may result in a broken view hierarchy. Add your view above %s in a common superview or insert it into your OpenSwiftUI content in a UIViewRepresentable instead."))
+    func didAddSubviewRecordsRuntimeIssue() {
+        let hostingView = _UIHostingView(rootView: EmptyView())
+        let subview = UIView()
+
+        Semantics.v7.test {
+            hostingView.addSubview(subview)
+        }
+
+        #expect(subview.superview === hostingView)
+    }
+}
+#endif