From c7e1976bfe1ed8df6b42f11644faf4b1476e7254 Mon Sep 17 00:00:00 2001
From: Matthew Horan <matt@matthoran.com>
Date: Wed, 20 Nov 2024 18:43:13 -0500
Subject: [PATCH] fix: only intercept events with waiting handlers

Previously, NativeReanimatedModule::handleRawEvent would intercept all
events received by the event listener. This resulted in an issue where
onLayout would not fire in JS on the New Architecture.

Instead, only intercept events with waiting handlers. This prevents
asJSIValue from being called on the Reanimated event loop and allows
onLayout to bubble up in JS.

See
https://github.com/facebook/react-native/blob/v0.76.2/packages/react-native/ReactCommon/react/renderer/components/view/BaseViewEventEmitter.cpp#L82-L112,
which prevents onLayout from being dispatched more than once.

asJSIValue evaluates the lambda above in
https://github.com/facebook/react-native/blob/v0.76.2/packages/react-native/ReactCommon/react/renderer/core/ValueFactoryEventPayload.cpp#L16.

Fixes #6684
---
 .../RuntimeTests/RuntimeTestsExample.tsx      |  2 +
 .../RuntimeTests/tests/core/onLayout.test.tsx | 46 +++++++++++++++++++
 .../NativeModules/NativeReanimatedModule.cpp  |  5 ++
 3 files changed, 53 insertions(+)
 create mode 100644 apps/common-app/src/examples/RuntimeTests/tests/core/onLayout.test.tsx

diff --git a/apps/common-app/src/examples/RuntimeTests/RuntimeTestsExample.tsx b/apps/common-app/src/examples/RuntimeTests/RuntimeTestsExample.tsx
index 6a460dbf4ef..4ad23f2af2d 100644
--- a/apps/common-app/src/examples/RuntimeTests/RuntimeTestsExample.tsx
+++ b/apps/common-app/src/examples/RuntimeTests/RuntimeTestsExample.tsx
@@ -51,6 +51,8 @@ export default function RuntimeTestsExample() {
             require('./tests/core/useDerivedValue/chain.test');
 
             require('./tests/core/useSharedValue/animationsCompilerApi.test');
+
+            require('./tests/core/onLayout.test');
           },
         },
         {
diff --git a/apps/common-app/src/examples/RuntimeTests/tests/core/onLayout.test.tsx b/apps/common-app/src/examples/RuntimeTests/tests/core/onLayout.test.tsx
new file mode 100644
index 00000000000..e132c1cfb68
--- /dev/null
+++ b/apps/common-app/src/examples/RuntimeTests/tests/core/onLayout.test.tsx
@@ -0,0 +1,46 @@
+import { useEffect } from 'react';
+import { StyleSheet, View } from 'react-native';
+import Animated, { runOnUI, useAnimatedStyle, useSharedValue } from 'react-native-reanimated';
+import { describe, expect, render, test, wait } from '../../ReJest/RuntimeTestsApi';
+
+let height = 0;
+
+const TestComponent = ({}) => {
+  const sv = useSharedValue(styles.smallBox.height);
+
+  const onLayout = event => {
+    height = event.nativeEvent.layout.height;
+  };
+
+  const animatedStyle = useAnimatedStyle(() => {
+    return { height: sv.value };
+  });
+
+  useEffect(() => {
+    runOnUI(() => {
+      sv.value += 100;
+    })();
+  });
+
+  return (
+    <View onLayout={onLayout}>
+      <Animated.View style={[styles.smallBox, animatedStyle]} />
+    </View>
+  );
+};
+
+describe('onLayout', () => {
+  test('is not intercepted', async () => {
+    await render(<TestComponent />);
+    await wait(100);
+    expect(height).toBe(200);
+  });
+});
+
+const styles = StyleSheet.create({
+  smallBox: {
+    width: 100,
+    height: 100,
+    backgroundColor: 'pink',
+  },
+});
diff --git a/packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/NativeReanimatedModule.cpp b/packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/NativeReanimatedModule.cpp
index 404ca6b6493..a6782f6f793 100644
--- a/packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/NativeReanimatedModule.cpp
+++ b/packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/NativeReanimatedModule.cpp
@@ -613,6 +613,11 @@ bool NativeReanimatedModule::handleRawEvent(
   if (eventType.rfind("top", 0) == 0) {
     eventType = "on" + eventType.substr(3);
   }
+
+  if (!isAnyHandlerWaitingForEvent(eventType, tag)) {
+    return false;
+  }
+
   jsi::Runtime &rt = uiWorkletRuntime_->getJSIRuntime();
   const auto &eventPayload = rawEvent.eventPayload;
   jsi::Value payload = eventPayload->asJSIValue(rt);