From eecd07c58bc4740e7ad0eedf113efb006ae7efc3 Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuelsusla@meta.com>
Date: Mon, 16 Jun 2025 04:50:47 -0700
Subject: [PATCH] Set final value via direct manipulation to fix animation
 glitches (#52012)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52012

changelog: [internal]

On iOS, once a prop on a view is controlled by animated, the control is never released to Fabric or React. That's why it is important to use direct manipulation to commit even final value.

Reviewed By: lenaic

Differential Revision: D76601913

fbshipit-source-id: ea02219e158f28977018b34ac7152b899723b35a
---
 .../Animated/__tests__/Animated-itest.js      | 55 ++++++++++++++++++-
 .../animated/NativeAnimatedNodesManager.cpp   |  6 ++
 2 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/packages/react-native/Libraries/Animated/__tests__/Animated-itest.js b/packages/react-native/Libraries/Animated/__tests__/Animated-itest.js
index d263ea0cbbc..a53ad8b8100 100644
--- a/packages/react-native/Libraries/Animated/__tests__/Animated-itest.js
+++ b/packages/react-native/Libraries/Animated/__tests__/Animated-itest.js
@@ -32,11 +32,9 @@ test('moving box by 100 points', () => {
           {
             width: 100,
             height: 100,
-            backgroundColor: 'red',
           },
           {transform: [{translateX}]},
         ]}
-        testID="box"
       />
     );
   }
@@ -146,3 +144,56 @@ test('animation driven by onScroll event', () => {
   // TODO(T226364699): this should `toBe(100)` but we are not syncing shadow tree yet.
   expect(viewElement.getBoundingClientRect().y).toBe(0);
 });
+
+test('animated opacity', () => {
+  let _opacity;
+  const viewRef = createRef<HostInstance>();
+
+  function MyApp() {
+    const opacity = useAnimatedValue(1);
+    _opacity = opacity;
+    return (
+      <Animated.View
+        ref={viewRef}
+        style={[
+          {
+            width: 100,
+            height: 100,
+            opacity: opacity,
+          },
+        ]}
+      />
+    );
+  }
+
+  const root = Fantom.createRoot();
+
+  Fantom.runTask(() => {
+    root.render(<MyApp />);
+  });
+
+  const viewElement = ensureInstance(viewRef.current, ReactNativeElement);
+
+  expect(viewElement.getBoundingClientRect().x).toBe(0);
+
+  Fantom.runTask(() => {
+    Animated.timing(_opacity, {
+      toValue: 0,
+      duration: 30,
+      useNativeDriver: true,
+    }).start();
+  });
+
+  Fantom.unstable_produceFramesForDuration(30);
+  // $FlowFixMe[incompatible-use]
+  expect(Fantom.unstable_getDirectManipulationProps(viewElement).opacity).toBe(
+    0,
+  );
+
+  // TODO: this shouldn't be neccessary but C++ Animated still schedules a React state update.
+  Fantom.runWorkLoop();
+
+  expect(root.getRenderedOutput({props: ['opacity']}).toJSX()).toEqual(
+    <rn-view opacity="0" />,
+  );
+});
diff --git a/packages/react-native/ReactCxxPlatform/react/renderer/animated/NativeAnimatedNodesManager.cpp b/packages/react-native/ReactCxxPlatform/react/renderer/animated/NativeAnimatedNodesManager.cpp
index d3f8dc105a8..4c5eb9b66ea 100644
--- a/packages/react-native/ReactCxxPlatform/react/renderer/animated/NativeAnimatedNodesManager.cpp
+++ b/packages/react-native/ReactCxxPlatform/react/renderer/animated/NativeAnimatedNodesManager.cpp
@@ -756,6 +756,12 @@ bool NativeAnimatedNodesManager::commitProps() {
 
   if (fabricCommitCallback_ != nullptr) {
     if (!updateViewProps_.empty()) {
+      // Must call direct manipulation to set final values on components.
+      if (directManipulationCallback_ != nullptr) {
+        for (const auto& [viewTag, props] : updateViewProps_) {
+          directManipulationCallback_(viewTag, folly::dynamic(props));
+        }
+      }
       fabricCommitCallback_(updateViewProps_);
       updateViewProps_.clear();
     }