Fix unbounded intensity cache issue (#671)

Author: Kyle-Ye

Sources/OpenSwiftUI/View/Control/SensoryFeedback/UIKit/UIKitSensoryFeedbackCache.swift

@@ -26,7 +26,7 @@ class AnyUIKitSensoryFeedbackCache {
 
 class UIKitSensoryFeedbackCache<V>: AnyUIKitSensoryFeedbackCache where V: View {
     weak var host: _UIHostingView<V>?
-    var cachedGenerators: [SensoryFeedback.FeedbackType: UIFeedbackGenerator] = [:]
+    private var cachedGenerators: [GeneratorCacheKey: UIFeedbackGenerator] = [:]
 
     override func implementation(
         type: SensoryFeedback.FeedbackType
@@ -59,6 +59,7 @@ class UIKitSensoryFeedbackCache<V>: AnyUIKitSensoryFeedbackCache where V: View {
             } createIfNeeded: {
                 UINotificationFeedbackGenerator()
             }
+        // OpenSwiftUI Addition:
         // SwiftUI implementation Bug: introduced since iOS 17 & iOS 26.2 is still not fixed
         // FB21332474
         case /*.increase, .decrease,*/ .selection:
@@ -108,17 +109,56 @@ class UIKitSensoryFeedbackCache<V>: AnyUIKitSensoryFeedbackCache where V: View {
         }
     }
 
+    /* OpenSwiftUI Addition Begin */
+
+    // MARK: - GeneratorCacheKey
+
+    /// A cache key that excludes intensity to prevent unbounded cache growth.
+    ///
+    /// Using `SensoryFeedback.FeedbackType` directly as cache key causes issues
+    /// because it includes the intensity value. Since intensity is a `Double`,
+    /// every different intensity creates a new cache entry and generator interaction.
+    /// The generator style (weight/flexibility) doesn't depend on intensity -
+    /// intensity is only used at feedback generation time.
+    private enum GeneratorCacheKey: Hashable {
+        case success
+        case warning
+        case error
+        case selection
+        case alignment
+        case pathComplete
+        case impactWeight(SensoryFeedback.Weight.Storage)
+        case impactFlexibility(SensoryFeedback.Flexibility.Storage)
+
+        init?(_ type: SensoryFeedback.FeedbackType) {
+            switch type {
+            case .success: self = .success
+            case .warning: self = .warning
+            case .error: self = .error
+            case .selection: self = .selection
+            case .alignment: self = .alignment
+            case .pathComplete: self = .pathComplete
+            case let .impactWeight(weight, _): self = .impactWeight(weight)
+            case let .impactFlexibility(flexibility, _): self = .impactFlexibility(flexibility)
+            default: return nil
+            }
+        }
+    }
+
+    /* OpenSwiftUI Addition End */
+
     private func getGenerator<Generator, Feedback>(
         _ type: SensoryFeedback.FeedbackType,
         work: (Generator) -> Feedback,
         createIfNeeded: () -> Generator
-    ) -> Feedback where Generator: UIFeedbackGenerator, Feedback: LocationBasedSensoryFeedback {
+    ) -> Feedback? where Generator: UIFeedbackGenerator, Feedback: LocationBasedSensoryFeedback {
+        guard let cacheKey = GeneratorCacheKey(type) else { return nil }
         let generator: Generator
-        if let cachedGenerator = cachedGenerators[type] {
+        if let cachedGenerator = cachedGenerators[cacheKey] {
             generator = cachedGenerator as! Generator
         } else {
             generator = createIfNeeded()
-            cachedGenerators[type] = generator
+            cachedGenerators[cacheKey] = generator
             host!.addInteraction(generator)
         }
         return work(generator)