fix: collect orphaned AnimatedPropsRegistry entry on last animated view unmount

packages/react-native-reanimated/Common/cpp/reanimated/Fabric/updates/AnimatedPropsRegistry.cpp

@@ -87,4 +87,10 @@ void AnimatedPropsRegistry::removeTag(const Tag tag) {
   timestampMap_.erase(tag);
 }
 
+void AnimatedPropsRegistry::removeAll() {
+  react_native_assert(UpdatesRegistryManager::isLockedByCurrentThread());
+  updatesRegistry_.clear();
+  timestampMap_.clear();
+}
+
 } // namespace reanimated

packages/react-native-reanimated/Common/cpp/reanimated/Fabric/updates/AnimatedPropsRegistry.h

@@ -18,6 +18,10 @@ class AnimatedPropsRegistry : public UpdatesRegistry {
   /// Also removes updates older than `cleanupTimestamp` from the registry.
   jsi::Value getUpdatesOlderThanTimestamp(jsi::Runtime &rt, double timestamp, double cleanupTimestamp);
 
+  /// Drops every entry. Called by the JS-side GC once the last animated view
+  /// unmount.
+  void removeAll();
+
  private:
   std::unordered_map<Tag, double> timestampMap_;
 

packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/ReanimatedModuleProxy.cpp

@@ -663,6 +663,11 @@ jsi::Value ReanimatedModuleProxy::getSettledUpdates(jsi::Runtime &rt) {
       rt, currentTimestamp - 1000 /* 1 second */, currentTimestamp - 2000 /* 2 seconds */);
 }
 
+void ReanimatedModuleProxy::removeOrphanedProps(jsi::Runtime &rt) {
+  auto lock = updatesRegistryManager_->lock();
+  animatedPropsRegistry_->removeAll();
+}
+
 bool ReanimatedModuleProxy::handleEvent(
     const std::string &eventName,
     const int emitterReactTag,
@@ -1579,6 +1584,14 @@ jsi::Object ReanimatedModuleProxy::toOptimizedObject(jsi::Runtime &rt) {
     return strongThis->getSettledUpdates(rt);
   });
 
+  addMethod<0>(rt, obj, "removeOrphanedProps", [weakThis = weak_from_this()](jsi::Runtime &rt, const jsi::Value &) {
+    auto strongThis = weakThis.lock();
+    if (!strongThis) {
+      return;
+    }
+    strongThis->removeOrphanedProps(rt);
+  });
+
   addMethod<2>(
       rt,
       obj,

packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/ReanimatedModuleProxy.h

@@ -149,6 +149,8 @@ class ReanimatedModuleProxy : public std::enable_shared_from_this<ReanimatedModu
 
   jsi::Value getSettledUpdates(jsi::Runtime &rt);
 
+  void removeOrphanedProps(jsi::Runtime &rt);
+
   void dispatchCommand(
       jsi::Runtime &rt,
       const jsi::Value &shadowNodeValue,

packages/react-native-reanimated/src/PropsRegistryGarbageCollector.ts

@@ -1,5 +1,7 @@
 'use strict';
 
+import { scheduleOnRN, scheduleOnUI } from 'react-native-worklets';
+
 import {
   unprocessColor,
   unprocessColorsInProps,
@@ -11,7 +13,6 @@ import { ReanimatedModule } from './ReanimatedModule';
 const FLUSH_INTERVAL_MS = 500;
 
 export const PropsRegistryGarbageCollector = {
-  viewsCount: 0,
   viewsMap: new Map<number, IAnimatedComponentInternal>(),
   intervalId: null as NodeJS.Timeout | null,
 
@@ -25,17 +26,20 @@ export const PropsRegistryGarbageCollector = {
       return;
     }
     this.viewsMap.set(viewTag, component);
-    this.viewsCount++;
-    if (this.viewsCount === 1) {
+    if (this.viewsMap.size === 1) {
       this.registerInterval();
     }
   },
 
   unregisterView(viewTag: number) {
-    this.viewsMap.delete(viewTag);
-    this.viewsCount--;
-    if (this.viewsCount === 0) {
+    // `delete` returns false when the tag wasn't tracked (the nested-component
+    // case registerView skipped above); bail to keep the count symmetric.
+    if (!this.viewsMap.delete(viewTag)) {
+      return;
+    }
+    if (this.viewsMap.size === 0) {
       this.unregisterInterval();
+      scheduleOrphanedPropsCleanup();
     }
   },
 
@@ -66,6 +70,25 @@ export const PropsRegistryGarbageCollector = {
   },
 };
 
+// The last animated view just unmounted, so the GC interval has stopped and no
+// commit will drain the registry. An in-flight animation frame can still re-add
+// the view's props; wait one UI frame for it to run, then clear the registry.
+function scheduleOrphanedPropsCleanup() {
+  scheduleOnUI(() => {
+    'worklet';
+    requestAnimationFrame(() => {
+      'worklet';
+      scheduleOnRN(removeOrphanedProps);
+    });
+  });
+}
+
+function removeOrphanedProps() {
+  if (PropsRegistryGarbageCollector.viewsMap.size === 0) {
+    ReanimatedModule.removeOrphanedProps();
+  }
+}
+
 function unprocessProps(props: StyleProps) {
   unprocessColorsInProps(props);
   unprocessBoxShadow(props);

packages/react-native-reanimated/src/ReanimatedModule/NativeReanimated.ts

@@ -244,6 +244,10 @@ See https://docs.swmansion.com/react-native-reanimated/docs/guides/troubleshooti
     return this.#reanimatedModuleProxy.getSettledUpdates();
   }
 
+  removeOrphanedProps() {
+    this.#reanimatedModuleProxy.removeOrphanedProps();
+  }
+
   registerPseudoStyles(
     shadowNodeWrapper: ShadowNodeWrapper,
     config: CSSPseudoStyleConfig
@@ -297,6 +301,8 @@ class DummyReanimatedModuleProxy implements ReanimatedModuleProxy {
     return [];
   }
 
+  removeOrphanedProps(): void {}
+
   registerPseudoStyles(): void {}
   unregisterPseudoStyles(): void {}
 }

packages/react-native-reanimated/src/ReanimatedModule/js-reanimated/JSReanimated.ts

@@ -349,6 +349,12 @@ class JSReanimated implements IReanimatedModule {
     );
   }
 
+  removeOrphanedProps(): void {
+    throw new Error(
+      '[Reanimated] `removeOrphanedProps` is not available in JSReanimated.'
+    );
+  }
+
   registerPseudoStyles(): void {
     throw new Error(
       '[Reanimated] `registerPseudoStyles` is not available in JSReanimated.'

packages/react-native-reanimated/src/ReanimatedModule/reanimatedModuleProxy.ts

@@ -94,6 +94,8 @@ export interface ReanimatedModuleProxy {
 
   getSettledUpdates(): SettledUpdate[];
 
+  removeOrphanedProps(): void;
+
   registerPseudoStyles(
     shadowNodeWrapper: ShadowNodeWrapper,
     config: CSSPseudoStyleConfig