xplat/js/react-native-github/packages/gradle-plugin/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/tests/TaskTestUtils.kt

Reviewed By: rshest

Differential Revision: D80931289

.github/workflows/prebuild-ios-dependencies.yml

@@ -179,8 +179,9 @@ jobs:
       - name: Compress and Rename dSYM
         if: steps.restore-xcframework.outputs.cache-hit != 'true'
         run: |
-          tar -cz -f packages/react-native/third-party/Symbols/ReactNativeDependencies${{ matrix.flavor }}.framework.dSYM.tar.gz \
-            packages/react-native/third-party/Symbols/ReactNativeDependencies.framework.dSYM
+          cd packages/react-native/third-party/Symbols/
+          tar -cz -f ../ReactNativeDependencies${{ matrix.flavor }}.framework.dSYM.tar.gz .
+          mv ../ReactNativeDependencies${{ matrix.flavor }}.framework.dSYM.tar.gz ./ReactNativeDependencies${{ matrix.flavor }}.framework.dSYM.tar.gz
       - name: Upload XCFramework Artifact
         uses: actions/upload-artifact@v4
         with:

packages/babel-plugin-codegen/__test_fixtures__/failures.js

@@ -81,10 +81,147 @@ export {Commands};
 export default (codegenNativeComponent<ModuleProps>('Module'): NativeType);
 `;
 
+const COMMANDS_WITH_COVERAGE_INVALID = `
+// @flow
+
+const codegenNativeComponent = require('codegenNativeComponent');
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+import type {ViewProps} from 'ViewPropTypes';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+// Coverage instrumentation of invalid Commands export - should still fail
+export const Commands = (cov_1234567890().s[0]++, {
+  hotspotUpdate: () => {},
+  scrollTo: () => {},
+});
+
+export default (codegenNativeComponent<ModuleProps>('Module'): NativeType);
+`;
+
+const COMMANDS_WITH_COVERAGE_WRONG_FUNCTION = `
+// @flow
+
+const codegenNativeComponent = require('codegenNativeComponent');
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+import type {ViewProps} from 'ViewPropTypes';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+// Coverage instrumentation of wrong function call - should fail
+export const Commands = (cov_abcdef123().s[0]++, someOtherFunction({
+  supportedCommands: ['pause', 'play'],
+}));
+
+export default (codegenNativeComponent<ModuleProps>('Module'): NativeType);
+`;
+
+const COMMANDS_WITH_COMPLEX_COVERAGE_INVALID = `
+// @flow
+
+const codegenNativeComponent = require('codegenNativeComponent');
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+import type {ViewProps} from 'ViewPropTypes';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+// Complex coverage instrumentation with invalid nested structure - should fail
+export const Commands = (
+  cov_xyz789().f[1]++,
+  cov_xyz789().s[2]++,
+  {
+    pause: (ref) => {},
+    play: (ref) => {},
+  }
+);
+
+export default (codegenNativeComponent<ModuleProps>('Module'): NativeType);
+`;
+
+const COMMANDS_WITH_COVERAGE_WRONG_NAME = `
+// @flow
+
+const codegenNativeCommands = require('codegenNativeCommands');
+const codegenNativeComponent = require('codegenNativeComponent');
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+import type {ViewProps} from 'ViewPropTypes';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+interface NativeCommands {
+  +pause: (viewRef: React.ElementRef<NativeType>) => void;
+  +play: (viewRef: React.ElementRef<NativeType>) => void;
+}
+
+// Coverage instrumentation with correct function but wrong export name - should fail
+export const WrongName = (cov_wrong123().s[0]++, codegenNativeCommands<NativeCommands>({
+  supportedCommands: ['pause', 'play'],
+}));
+
+export default (codegenNativeComponent<ModuleProps>('Module'): NativeType);
+`;
+
+const COMMANDS_WITH_COVERAGE_TYPE_CAST_INVALID = `
+// @flow
+
+const codegenNativeComponent = require('codegenNativeComponent');
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+import type {ViewProps} from 'ViewPropTypes';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+interface NativeCommands {
+  +pause: (viewRef: React.ElementRef<NativeType>) => void;
+  +play: (viewRef: React.ElementRef<NativeType>) => void;
+}
+
+// Coverage instrumentation with type cast but wrong function - should fail
+export const Commands: NativeCommands = (cov_cast123().s[0]++, invalidFunction({
+  supportedCommands: ['pause', 'play'],
+}));
+
+export default (codegenNativeComponent<ModuleProps>('Module'): NativeType);
+`;
+
 module.exports = {
   'CommandsExportedWithDifferentNameNativeComponent.js':
     COMMANDS_EXPORTED_WITH_DIFFERENT_NAME,
   'CommandsExportedWithShorthandNativeComponent.js':
     COMMANDS_EXPORTED_WITH_SHORTHAND,
   'OtherCommandsExportNativeComponent.js': OTHER_COMMANDS_EXPORT,
+  'CommandsWithCoverageInvalidNativeComponent.js':
+    COMMANDS_WITH_COVERAGE_INVALID,
+  'CommandsWithCoverageWrongFunctionNativeComponent.js':
+    COMMANDS_WITH_COVERAGE_WRONG_FUNCTION,
+  'CommandsWithComplexCoverageInvalidNativeComponent.js':
+    COMMANDS_WITH_COMPLEX_COVERAGE_INVALID,
+  'CommandsWithCoverageWrongNameNativeComponent.js':
+    COMMANDS_WITH_COVERAGE_WRONG_NAME,
+  'CommandsWithCoverageTypeCastInvalidNativeComponent.js':
+    COMMANDS_WITH_COVERAGE_TYPE_CAST_INVALID,
 };

packages/babel-plugin-codegen/__test_fixtures__/fixtures.js

@@ -59,6 +59,92 @@ export default codegenNativeComponent<ModuleProps>('Module', {
 });
 `;
 
+// Coverage instrumentation test cases - should be recognized as valid
+const COMMANDS_WITH_SIMPLE_COVERAGE = `
+// @flow
+
+const codegenNativeCommands = require('codegenNativeCommands');
+const codegenNativeComponent = require('codegenNativeComponent');
+
+import type {ViewProps} from 'ViewPropTypes';
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+interface NativeCommands {
+  +pause: (viewRef: React.ElementRef<NativeType>) => void;
+  +play: (viewRef: React.ElementRef<NativeType>) => void;
+}
+
+export const Commands = (cov_1234567890.s[0]++, codegenNativeCommands<NativeCommands>({
+  supportedCommands: ['pause', 'play'],
+}));
+
+export default codegenNativeComponent<ModuleProps>('Module');
+`;
+
+const COMMANDS_WITH_COMPLEX_COVERAGE = `
+// @flow
+
+const codegenNativeCommands = require('codegenNativeCommands');
+const codegenNativeComponent = require('codegenNativeComponent');
+
+import type {ViewProps} from 'ViewPropTypes';
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+interface NativeCommands {
+  +seek: (viewRef: React.ElementRef<NativeType>, position: number) => void;
+  +stop: (viewRef: React.ElementRef<NativeType>) => void;
+}
+
+export const Commands = (
+  cov_abcdef123().f[2]++,
+  cov_abcdef123().s[5]++,
+  codegenNativeCommands<NativeCommands>({
+    supportedCommands: ['seek', 'stop'],
+  })
+);
+
+export default codegenNativeComponent<ModuleProps>('Module');
+`;
+
+const COMMANDS_WITH_TYPE_CAST_COVERAGE = `
+// @flow
+
+const codegenNativeCommands = require('codegenNativeCommands');
+const codegenNativeComponent = require('codegenNativeComponent');
+
+import type {ViewProps} from 'ViewPropTypes';
+import type {NativeComponentType} from 'codegenNativeComponent';
+
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps,
+|}>;
+
+type NativeType = NativeComponentType<ModuleProps>;
+
+interface NativeCommands {
+  +mute: (viewRef: React.ElementRef<NativeType>) => void;
+  +unmute: (viewRef: React.ElementRef<NativeType>) => void;
+}
+
+export const Commands: NativeCommands = (cov_xyz789().s[1]++, codegenNativeCommands<NativeCommands>({
+  supportedCommands: ['mute', 'unmute'],
+}));
+
+export default codegenNativeComponent<ModuleProps>('Module');
+`;
+
 const FULL_NATIVE_COMPONENT_WITH_TYPE_EXPORT = `
 // @flow
 
@@ -107,4 +193,9 @@ module.exports = {
   'NotANativeComponent.js': NOT_A_NATIVE_COMPONENT,
   'FullNativeComponent.js': FULL_NATIVE_COMPONENT,
   'FullTypedNativeComponent.js': FULL_NATIVE_COMPONENT_WITH_TYPE_EXPORT,
+  'CommandsWithSimpleCoverageNativeComponent.js': COMMANDS_WITH_SIMPLE_COVERAGE,
+  'CommandsWithComplexCoverageNativeComponent.js':
+    COMMANDS_WITH_COMPLEX_COVERAGE,
+  'CommandsWithTypeCastCoverageNativeComponent.js':
+    COMMANDS_WITH_TYPE_CAST_COVERAGE,
 };

packages/babel-plugin-codegen/__tests__/__snapshots__/index-test.js.snap

@@ -1,5 +1,77 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`Babel plugin inline view configs can inline config for CommandsWithComplexCoverageNativeComponent.js 1`] = `
+"// @flow
+
+const codegenNativeCommands = require('codegenNativeCommands');
+const codegenNativeComponent = require('codegenNativeComponent');
+import type { ViewProps } from 'ViewPropTypes';
+import type { NativeComponentType } from 'codegenNativeComponent';
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps
+|}>;
+type NativeType = NativeComponentType<ModuleProps>;
+interface NativeCommands {
+  +seek: (viewRef: React.ElementRef<NativeType>, position: number) => void,
+  +stop: (viewRef: React.ElementRef<NativeType>) => void,
+}
+const NativeComponentRegistry = require('react-native/Libraries/NativeComponent/NativeComponentRegistry');
+let nativeComponentName = 'Module';
+export const __INTERNAL_VIEW_CONFIG = {
+  uiViewClassName: \\"Module\\",
+  validAttributes: {}
+};
+export default NativeComponentRegistry.get(nativeComponentName, () => __INTERNAL_VIEW_CONFIG);"
+`;
+
+exports[`Babel plugin inline view configs can inline config for CommandsWithSimpleCoverageNativeComponent.js 1`] = `
+"// @flow
+
+const codegenNativeCommands = require('codegenNativeCommands');
+const codegenNativeComponent = require('codegenNativeComponent');
+import type { ViewProps } from 'ViewPropTypes';
+import type { NativeComponentType } from 'codegenNativeComponent';
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps
+|}>;
+type NativeType = NativeComponentType<ModuleProps>;
+interface NativeCommands {
+  +pause: (viewRef: React.ElementRef<NativeType>) => void,
+  +play: (viewRef: React.ElementRef<NativeType>) => void,
+}
+const NativeComponentRegistry = require('react-native/Libraries/NativeComponent/NativeComponentRegistry');
+let nativeComponentName = 'Module';
+export const __INTERNAL_VIEW_CONFIG = {
+  uiViewClassName: \\"Module\\",
+  validAttributes: {}
+};
+export default NativeComponentRegistry.get(nativeComponentName, () => __INTERNAL_VIEW_CONFIG);"
+`;
+
+exports[`Babel plugin inline view configs can inline config for CommandsWithTypeCastCoverageNativeComponent.js 1`] = `
+"// @flow
+
+const codegenNativeCommands = require('codegenNativeCommands');
+const codegenNativeComponent = require('codegenNativeComponent');
+import type { ViewProps } from 'ViewPropTypes';
+import type { NativeComponentType } from 'codegenNativeComponent';
+type ModuleProps = $ReadOnly<{|
+  ...ViewProps
+|}>;
+type NativeType = NativeComponentType<ModuleProps>;
+interface NativeCommands {
+  +mute: (viewRef: React.ElementRef<NativeType>) => void,
+  +unmute: (viewRef: React.ElementRef<NativeType>) => void,
+}
+const NativeComponentRegistry = require('react-native/Libraries/NativeComponent/NativeComponentRegistry');
+let nativeComponentName = 'Module';
+export const __INTERNAL_VIEW_CONFIG = {
+  uiViewClassName: \\"Module\\",
+  validAttributes: {}
+};
+export default NativeComponentRegistry.get(nativeComponentName, () => __INTERNAL_VIEW_CONFIG);"
+`;
+
 exports[`Babel plugin inline view configs can inline config for FullNativeComponent.js 1`] = `
 "// @flow
 
@@ -153,6 +225,61 @@ exports[`Babel plugin inline view configs fails on inline config for CommandsExp
   24 |"
 `;
 
+exports[`Babel plugin inline view configs fails on inline config for CommandsWithComplexCoverageInvalidNativeComponent.js 1`] = `
+"/CommandsWithComplexCoverageInvalidNativeComponent.js: 'Commands' is a reserved export and may only be used to export the result of codegenNativeCommands.
+  14 |
+  15 | // Complex coverage instrumentation with invalid nested structure - should fail
+> 16 | export const Commands = (
+     | ^
+  17 |   cov_xyz789().f[1]++,
+  18 |   cov_xyz789().s[2]++,
+  19 |   {"
+`;
+
+exports[`Babel plugin inline view configs fails on inline config for CommandsWithCoverageInvalidNativeComponent.js 1`] = `
+"/CommandsWithCoverageInvalidNativeComponent.js: 'Commands' is a reserved export and may only be used to export the result of codegenNativeCommands.
+  14 |
+  15 | // Coverage instrumentation of invalid Commands export - should still fail
+> 16 | export const Commands = (cov_1234567890().s[0]++, {
+     | ^
+  17 |   hotspotUpdate: () => {},
+  18 |   scrollTo: () => {},
+  19 | });"
+`;
+
+exports[`Babel plugin inline view configs fails on inline config for CommandsWithCoverageTypeCastInvalidNativeComponent.js 1`] = `
+"/CommandsWithCoverageTypeCastInvalidNativeComponent.js: 'Commands' is a reserved export and may only be used to export the result of codegenNativeCommands.
+  19 |
+  20 | // Coverage instrumentation with type cast but wrong function - should fail
+> 21 | export const Commands: NativeCommands = (cov_cast123().s[0]++, invalidFunction({
+     | ^
+  22 |   supportedCommands: ['pause', 'play'],
+  23 | }));
+  24 |"
+`;
+
+exports[`Babel plugin inline view configs fails on inline config for CommandsWithCoverageWrongFunctionNativeComponent.js 1`] = `
+"/CommandsWithCoverageWrongFunctionNativeComponent.js: 'Commands' is a reserved export and may only be used to export the result of codegenNativeCommands.
+  14 |
+  15 | // Coverage instrumentation of wrong function call - should fail
+> 16 | export const Commands = (cov_abcdef123().s[0]++, someOtherFunction({
+     | ^
+  17 |   supportedCommands: ['pause', 'play'],
+  18 | }));
+  19 |"
+`;
+
+exports[`Babel plugin inline view configs fails on inline config for CommandsWithCoverageWrongNameNativeComponent.js 1`] = `
+"/CommandsWithCoverageWrongNameNativeComponent.js: Native commands must be exported with the name 'Commands'
+  20 |
+  21 | // Coverage instrumentation with correct function but wrong export name - should fail
+> 22 | export const WrongName = (cov_wrong123().s[0]++, codegenNativeCommands<NativeCommands>({
+     | ^
+  23 |   supportedCommands: ['pause', 'play'],
+  24 | }));
+  25 |"
+`;
+
 exports[`Babel plugin inline view configs fails on inline config for OtherCommandsExportNativeComponent.js 1`] = `
 "/OtherCommandsExportNativeComponent.js: 'Commands' is a reserved export and may only be used to export the result of codegenNativeCommands.
   17 | }

packages/babel-plugin-codegen/index.js

@@ -102,6 +102,58 @@ function isCodegenDeclaration(declaration) {
   return false;
 }
 
+function isCodegenNativeCommandsDeclaration(declaration) {
+  if (!declaration) {
+    return false;
+  }
+
+  // Handle direct calls: codegenNativeCommands()
+  if (
+    declaration.type === 'CallExpression' &&
+    declaration.callee &&
+    declaration.callee.type === 'Identifier' &&
+    declaration.callee.name === 'codegenNativeCommands'
+  ) {
+    return true;
+  }
+
+  // Handle coverage instrumentation: (cov_xxx().s[0]++, codegenNativeCommands())
+  if (declaration.type === 'SequenceExpression' && declaration.expressions) {
+    // Get the last expression in the sequence (the actual function call)
+    const lastExpression =
+      declaration.expressions[declaration.expressions.length - 1];
+    // Recursively check if the last expression is a valid codegenNativeCommands call
+    return isCodegenNativeCommandsDeclaration(lastExpression);
+  }
+
+  // Handle Flow type casts: (codegenNativeCommands(): NativeCommands)
+  if (
+    (declaration.type === 'TypeCastExpression' ||
+      declaration.type === 'AsExpression') &&
+    declaration.expression &&
+    declaration.expression.type === 'CallExpression' &&
+    declaration.expression.callee &&
+    declaration.expression.callee.type === 'Identifier' &&
+    declaration.expression.callee.name === 'codegenNativeCommands'
+  ) {
+    return true;
+  }
+
+  // Handle TypeScript assertions: codegenNativeCommands() as NativeCommands
+  if (
+    declaration.type === 'TSAsExpression' &&
+    declaration.expression &&
+    declaration.expression.type === 'CallExpression' &&
+    declaration.expression.callee &&
+    declaration.expression.callee.type === 'Identifier' &&
+    declaration.expression.callee.name === 'codegenNativeCommands'
+  ) {
+    return true;
+  }
+
+  return false;
+}
+
 module.exports = function ({parse, types: t}) {
   return {
     pre(state) {
@@ -125,12 +177,12 @@ module.exports = function ({parse, types: t}) {
           const firstDeclaration = path.node.declaration.declarations[0];
 
           if (firstDeclaration.type === 'VariableDeclarator') {
-            if (
-              firstDeclaration.init &&
-              firstDeclaration.init.type === 'CallExpression' &&
-              firstDeclaration.init.callee.type === 'Identifier' &&
-              firstDeclaration.init.callee.name === 'codegenNativeCommands'
-            ) {
+            // Check if this is a valid codegenNativeCommands call, handling type annotations
+            const isValidCommandsExport = isCodegenNativeCommandsDeclaration(
+              firstDeclaration.init,
+            );
+
+            if (isValidCommandsExport) {
               if (
                 firstDeclaration.id.type === 'Identifier' &&
                 firstDeclaration.id.name !== 'Commands'

packages/community-cli-plugin/package.json

@@ -40,6 +40,9 @@
   "peerDependenciesMeta": {
     "@react-native-community/cli": {
       "optional": true
+    },
+    "@react-native/metro-config": {
+      "optional": true
     }
   },
   "engines": {

packages/community-cli-plugin/src/commands/start/middleware.js

@@ -31,9 +31,9 @@ type MiddlewareReturn = {
   ...
 };
 
-// $FlowFixMe
+// $FlowFixMe[incompatible-type]
 const unusedStubWSServer: ws$WebSocketServer = {};
-// $FlowFixMe
+// $FlowFixMe[incompatible-type]
 const unusedMiddlewareStub: Server = {};
 
 const communityMiddlewareFallback = {

packages/debugger-shell/src/electron/MainInstanceEntryPoint.js

@@ -36,7 +36,7 @@ function handleLaunchArgs(argv: string[]) {
   });
 
   // Find an existing window for this app and launch configuration.
-  const existingWindow = BrowserWindow.getAllWindows().find(window => {
+  let frontendWindow = BrowserWindow.getAllWindows().find(window => {
     const metadata = windowMetadata.get(window);
     if (!metadata) {
       return false;
@@ -44,41 +44,37 @@ function handleLaunchArgs(argv: string[]) {
     return metadata.windowKey === windowKey;
   });
 
-  if (existingWindow) {
+  if (frontendWindow) {
     // If the window is already visible, flash it.
-    if (existingWindow.isVisible()) {
-      existingWindow.flashFrame(true);
+    if (frontendWindow.isVisible()) {
+      frontendWindow.flashFrame(true);
       setTimeout(() => {
-        existingWindow.flashFrame(false);
+        frontendWindow.flashFrame(false);
       }, 1000);
     }
-    if (process.platform === 'darwin') {
-      app.focus({
-        steal: true,
-      });
-    }
-    existingWindow.focus();
-    return;
+  } else {
+    // Create the browser window.
+    frontendWindow = new BrowserWindow({
+      width: 1200,
+      height: 600,
+      webPreferences: {
+        partition: 'persist:react-native-devtools',
+        preload: require.resolve('./preload.js'),
+      },
+      // Icon for Linux
+      icon: path.join(__dirname, 'resources', 'icon.png'),
+    });
   }
 
-  // Create the browser window.
-  const frontendWindow = new BrowserWindow({
-    width: 1200,
-    height: 600,
-    webPreferences: {
-      partition: 'persist:react-native-devtools',
-      preload: require.resolve('./preload.js'),
-    },
-    // Icon for Linux
-    icon: path.join(__dirname, 'resources', 'icon.png'),
-  });
-
   // Open links in the default browser instead of in new Electron windows.
   frontendWindow.webContents.setWindowOpenHandler(({url}) => {
     shell.openExternal(url);
     return {action: 'deny'};
   });
 
+  // TODO: If the window contains a live, working frontend instance with a valid connection to the backend,
+  // we should avoid this reload and instead send the frontend a message to handle the launch arguments
+  // dynamically (e.g. update the launch ID for telemetry purposes, handle deeplinking to a specific CDT panel, etc).
   frontendWindow.loadURL(frontendUrl);
 
   windowMetadata.set(frontendWindow, {
@@ -90,6 +86,7 @@ function handleLaunchArgs(argv: string[]) {
       steal: true,
     });
   }
+  frontendWindow.focus();
 }
 
 app.whenReady().then(() => {

packages/gradle-plugin/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/tasks/internal/PrepareBoostTaskTest.kt

@@ -58,11 +58,11 @@ class PrepareBoostTaskTest {
     val boostThirdPartyJniPath = tempFolder.newFolder("boostpath/jni")
     val output = tempFolder.newFolder("output")
     val task =
-        createTestTask<PrepareBoostTask> {
-          it.boostPath.setFrom(boostpath)
-          it.boostThirdPartyJniPath.set(boostThirdPartyJniPath)
-          it.boostVersion.set("1.0.0")
-          it.outputDir.set(output)
+        createTestTask<PrepareBoostTask> { task ->
+          task.boostPath.setFrom(boostpath)
+          task.boostThirdPartyJniPath.set(boostThirdPartyJniPath)
+          task.boostVersion.set("1.0.0")
+          task.outputDir.set(output)
         }
     File(boostpath, "asm/asm.S").apply {
       parentFile.mkdirs()
@@ -79,11 +79,11 @@ class PrepareBoostTaskTest {
     val boostThirdPartyJniPath = tempFolder.newFolder("boostpath/jni")
     val output = tempFolder.newFolder("output")
     val task =
-        createTestTask<PrepareBoostTask> {
-          it.boostPath.setFrom(boostpath)
-          it.boostThirdPartyJniPath.set(boostThirdPartyJniPath)
-          it.boostVersion.set("1.0.0")
-          it.outputDir.set(output)
+        createTestTask<PrepareBoostTask> { task ->
+          task.boostPath.setFrom(boostpath)
+          task.boostThirdPartyJniPath.set(boostThirdPartyJniPath)
+          task.boostVersion.set("1.0.0")
+          task.outputDir.set(output)
         }
     File(boostpath, "boost_1.0.0/boost/config.hpp").apply {
       parentFile.mkdirs()
@@ -100,11 +100,11 @@ class PrepareBoostTaskTest {
     val boostThirdPartyJniPath = tempFolder.newFolder("boostpath/jni")
     val output = tempFolder.newFolder("output")
     val task =
-        createTestTask<PrepareBoostTask> {
-          it.boostPath.setFrom(boostpath)
-          it.boostThirdPartyJniPath.set(boostThirdPartyJniPath)
-          it.boostVersion.set("1.0.0")
-          it.outputDir.set(output)
+        createTestTask<PrepareBoostTask> { task ->
+          task.boostPath.setFrom(boostpath)
+          task.boostThirdPartyJniPath.set(boostThirdPartyJniPath)
+          task.boostVersion.set("1.0.0")
+          task.outputDir.set(output)
         }
     File(boostpath, "boost/boost/config.hpp").apply {
       parentFile.mkdirs()

packages/gradle-plugin/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/tasks/internal/PreparePrefabHeadersTaskTest.kt

@@ -186,9 +186,9 @@ class PreparePrefabHeadersTaskTest {
 
     val project = createProject(projectDir = tempFolder.root)
     val task =
-        createTestTask<PreparePrefabHeadersTask>(project = project) {
-          it.outputDir.set(outputDir)
-          it.input.set(listOf(PrefabPreprocessingEntry("sample_library", "boost/" to "")))
+        createTestTask<PreparePrefabHeadersTask>(project = project) { task ->
+          task.outputDir.set(outputDir)
+          task.input.set(listOf(PrefabPreprocessingEntry("sample_library", "boost/" to "")))
         }
 
     task.taskAction()

packages/gradle-plugin/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/tests/TaskTestUtils.kt

@@ -59,8 +59,8 @@ internal fun createZip(dest: File, paths: List<String>) {
   val uri = URI.create("jar:file:$dest")
 
   FileSystems.newFileSystem(uri, env).use { zipfs ->
-    paths.forEach {
-      val zipEntryPath = zipfs.getPath(it)
+    paths.forEach { path ->
+      val zipEntryPath = zipfs.getPath(path)
       val zipEntryFolder = zipEntryPath.subpath(0, zipEntryPath.nameCount - 1)
       Files.createDirectories(zipEntryFolder)
       Files.createFile(zipEntryPath)

packages/normalize-color/__tests__/normalizeColor-test.js

@@ -47,7 +47,7 @@ it('refuses non-spec compliant colors', () => {
   expect(normalizeColor('rgb (0, 1, 2)')).toBe(null);
   expect(normalizeColor('rgba(0 0 0 0.0)')).toBe(null);
   expect(normalizeColor('hsv(0, 1, 2)')).toBe(null);
-  // $FlowExpectedError - Intentionally malformed argument.
+  // $FlowExpectedError[incompatible-type]  - Intentionally malformed argument.
   expect(normalizeColor({r: 10, g: 10, b: 10})).toBe(null);
   expect(normalizeColor('hsl(1%, 2, 3)')).toBe(null);
   expect(normalizeColor('rgb(1%, 2%, 3%)')).toBe(null);

packages/react-native-babel-transformer/src/index.js

@@ -218,7 +218,7 @@ const transform /*: BabelTransformer['transform'] */ = ({
 
     // The result from `transformFromAstSync` can be null (if the file is ignored)
     if (!result) {
-      /* $FlowFixMe BabelTransformer specifies that the `ast` can never be null but
+      /* $FlowFixMe[incompatible-type] BabelTransformer specifies that the `ast` can never be null but
        * the function returns here. Discovered when typing `BabelNode`. */
       return {ast: null};
     }

packages/react-native-codegen/src/parsers/typescript/components/componentsUtils.js

@@ -350,6 +350,8 @@ function setDefaultValue(
       common.default = ((defaultValue ? defaultValue : 0): number);
       break;
     case 'FloatTypeAnnotation':
+      /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+       * roll out. See https://fburl.com/workplace/5whu3i34. */
       common.default = ((defaultValue === null
         ? null
         : defaultValue
@@ -357,6 +359,8 @@ function setDefaultValue(
           : 0): number | null);
       break;
     case 'BooleanTypeAnnotation':
+      /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+       * roll out. See https://fburl.com/workplace/5whu3i34. */
       common.default = defaultValue === null ? null : !!defaultValue;
       break;
     case 'StringTypeAnnotation':

packages/react-native-compatibility-check/src/ErrorFormatting.js

@@ -275,7 +275,7 @@ export function formatNativeSpecErrorStore(
 export function formatDiffSet(summary: DiffSummary): FormattedDiffSummary {
   const summaryStatus = summary.status;
   if (summaryStatus === 'ok' || summaryStatus === 'patchable') {
-    // $FlowFixMe I don't think we can ever get in this branch
+    // $FlowFixMe[incompatible-type] I don't think we can ever get in this branch
     return summary;
   }
   const hasteModules = Object.keys(summary.incompatibilityReport);

packages/react-native/Libraries/ActionSheetIOS/ActionSheetIOS.js

@@ -77,6 +77,8 @@ const ActionSheetIOS = {
     callback: (buttonIndex: number) => void,
   ) {
     invariant(
+      /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+       * roll out. See https://fburl.com/workplace/5whu3i34. */
       typeof options === 'object' && options !== null,
       'Options must be a valid object',
     );
@@ -162,6 +164,8 @@ const ActionSheetIOS = {
     successCallback: Function | ((success: boolean, method: ?string) => void),
   ) {
     invariant(
+      /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+       * roll out. See https://fburl.com/workplace/5whu3i34. */
       typeof options === 'object' && options !== null,
       'Options must be a valid object',
     );

packages/react-native/Libraries/Animated/components/AnimatedScrollView.js

@@ -54,7 +54,8 @@ const AnimatedScrollView: AnimatedComponentType<
     props.style != null
   ) {
     return (
-      // $FlowFixMe - It should return an Animated ScrollView but it returns a ScrollView with Animated props applied.
+      // $FlowFixMe[incompatible-type] - It should return an Animated ScrollView but it returns a ScrollView with Animated props applied.
+      // $FlowFixMe[incompatible-variance]
       <AnimatedScrollViewWithInvertedRefreshControl
         scrollEventThrottle={0.0001}
         {...props}

packages/react-native/Libraries/Animated/components/AnimatedSectionList.js

@@ -14,7 +14,7 @@ import SectionList, {type SectionListProps} from '../../Lists/SectionList';
 import createAnimatedComponent from '../createAnimatedComponent';
 import * as React from 'react';
 
-// $FlowFixMe
+// $FlowFixMe[incompatible-type]
 export default (createAnimatedComponent(SectionList): component<
   // $FlowExpectedError[unclear-type]
   ItemT = any,

packages/react-native/Libraries/Blob/URLSearchParams.js

@@ -18,6 +18,8 @@ export class URLSearchParams {
   }
 
   constructor(params?: Record<string, string> | string | [string, string][]) {
+    /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+     * roll out. See https://fburl.com/workplace/5whu3i34. */
     if (params === null) {
       return;
     }

packages/react-native/Libraries/Components/ScrollView/ScrollView.js

@@ -1503,7 +1503,7 @@ class ScrollView extends React.Component<ScrollViewProps, ScrollViewState> {
         keyboardNeverPersistTaps &&
         this._keyboardIsDismissible() &&
         e.target != null &&
-        // $FlowFixMe Error supressed during the migration of HostInstance to ReactNativeElement
+        // $FlowFixMe[incompatible-type] Error supressed during the migration of HostInstance to ReactNativeElement
         !TextInputState.isTextInput(e.target)
       ) {
         return true;

packages/react-native/Libraries/Components/TextInput/TextInputState.js

@@ -88,7 +88,7 @@ function focusTextInput(textField: ?HostInstance) {
   if (textField != null) {
     const fieldCanBeFocused =
       currentlyFocusedInputRef !== textField &&
-      // $FlowFixMe - `currentProps` is missing in `NativeMethods`
+      // $FlowFixMe[prop-missing] - `currentProps` is missing in `NativeMethods`
       textField.currentProps?.editable !== false;
 
     if (!fieldCanBeFocused) {

packages/react-native/Libraries/Components/TextInput/__tests__/TextInput-test.js

@@ -123,7 +123,7 @@ jest.unmock('../TextInput');
         throw new Error('Expected `textInputElement` to be non-null');
       }
 
-      // $FlowFixMe
+      // $FlowFixMe[prop-missing]
       textInputElement.currentProps = textInputElement.props;
       expect(textInputElement.isFocused()).toBe(false);
 

packages/react-native/Libraries/Image/Image.android.js

@@ -387,7 +387,7 @@ if (ReactNativeFeatureFlags.reduceDefaultPropsInImage()) {
       // in order to have a better alignment between platforms in the future.
       src: sources,
       source: sources,
-      /* $FlowFixMe(>=0.78.0 site=react_native_android_fb) This issue was found
+      /* $FlowFixMe[prop-missing](>=0.78.0 site=react_native_android_fb) This issue was found
        * when making Flow check .android.js files. */
       headers: (source?.[0]?.headers || source?.headers: ?{[string]: string}),
       defaultSource: defaultSource ? defaultSource.uri : null,

packages/react-native/Libraries/Lists/__flowtests__/FlatList-flowtest.js

@@ -36,7 +36,7 @@ export function testBadDataWithTypicalItem(): React.Node {
       key: 1,
     },
   ];
-  // $FlowExpectedError - bad title type 6, should be string
+  // $FlowExpectedError[incompatible-type] - bad title type 6, should be string
   return <FlatList renderItem={renderMyListItem} data={data} />;
 }
 
@@ -46,7 +46,7 @@ export function testMissingFieldWithTypicalItem(): React.Node {
       key: 1,
     },
   ];
-  // $FlowExpectedError - missing title
+  // $FlowExpectedError[incompatible-type] - missing title
   return <FlatList renderItem={renderMyListItem} data={data} />;
 }
 
@@ -62,7 +62,7 @@ export function testGoodDataWithBadCustomRenderItemFunction(): React.Node {
       renderItem={info => (
         <span>
           {
-            // $FlowExpectedError - bad widgetCount type 6, should be Object
+            // $FlowExpectedError[prop-missing] - bad widgetCount type 6, should be Object
             info.item.widget.missingProp
           }
         </span>
@@ -80,22 +80,26 @@ export function testBadRenderItemFunction(): $ReadOnlyArray<React.Node> {
     },
   ];
   return [
-    // $FlowExpectedError - title should be inside `item`
+    // $FlowExpectedError[incompatible-type] - title should be inside `item`
+    // $FlowExpectedError[incompatible-exact]
     <FlatList renderItem={(info: {title: string}) => <span />} data={data} />,
     <FlatList
-      // $FlowExpectedError - bad index type string, should be number
+      // $FlowExpectedError[incompatible-type] - bad index type string, should be number
+      // $FlowExpectedError[incompatible-exact]
+      // $FlowExpectedError[unclear-type]
       renderItem={(info: {item: any, index: string}) => <span />}
       data={data}
     />,
     <FlatList
-      // $FlowExpectedError - bad title type number, should be string
+      // $FlowExpectedError[incompatible-type] - bad index type string, should be number
+      // $FlowExpectedError[incompatible-exact]
       renderItem={(info: {item: {title: number}}) => <span />}
-      // $FlowExpectedError - bad title type number, should be string
+      // $FlowExpectedError[incompatible-type] - bad title type number, should be string
       data={data}
     />,
     // EverythingIsFine
     <FlatList
-      // $FlowExpectedError - bad title type number, should be string
+      // $FlowExpectedError[incompatible-type] - bad title type number, should be string
       renderItem={(info: {item: {title: string, ...}, ...}) => <span />}
       data={data}
     />,
@@ -104,11 +108,11 @@ export function testBadRenderItemFunction(): $ReadOnlyArray<React.Node> {
 
 export function testOtherBadProps(): $ReadOnlyArray<React.Node> {
   return [
-    // $FlowExpectedError - bad numColumns type "lots"
+    // $FlowExpectedError[incompatible-type] - bad numColumns type "lots"
     <FlatList renderItem={renderMyListItem} data={[]} numColumns="lots" />,
-    // $FlowExpectedError - bad windowSize type "big"
+    // $FlowExpectedError[incompatible-type] - bad windowSize type "big"
     <FlatList renderItem={renderMyListItem} data={[]} windowSize="big" />,
-    // $FlowExpectedError - missing `data` prop
+    // $FlowExpectedError[incompatible-type] - missing `data` prop
     <FlatList renderItem={renderMyListItem} />,
   ];
 }

packages/react-native/Libraries/Lists/__flowtests__/SectionList-flowtest.js

@@ -55,12 +55,13 @@ export function testBadRenderItemFunction(): $ReadOnlyArray<React.Node> {
   ];
   return [
     <SectionList
-      // $FlowExpectedError - title should be inside `item`
+      // $FlowExpectedError[incompatible-type] - title should be inside `item`
       renderItem={(info: {title: string, ...}) => <span />}
       sections={sections}
     />,
     <SectionList
-      // $FlowExpectedError - bad index type string, should be number
+      // $FlowExpectedError[incompatible-type] - bad index type string, should be number
+      // $FlowExpectedError[incompatible-exact]
       renderItem={(info: {index: string}) => <span />}
       sections={sections}
     />,
@@ -78,14 +79,14 @@ export function testBadInheritedDefaultProp(): React.MixedElement {
     <SectionList
       renderItem={renderMyListItem}
       sections={sections}
-      // $FlowExpectedError - bad windowSize type "big"
+      // $FlowExpectedError[incompatible-type] - bad windowSize type "big"
       windowSize="big"
     />
   );
 }
 
 export function testMissingData(): React.MixedElement {
-  // $FlowExpectedError - missing `sections` prop
+  // $FlowExpectedError[incompatible-type] - missing `sections` prop
   return <SectionList renderItem={renderMyListItem} />;
 }
 
@@ -122,7 +123,7 @@ export function testBadSectionsMetadata(): React.MixedElement {
     <SectionList
       renderSectionHeader={renderMyHeader}
       renderItem={renderMyListItem}
-      /* $FlowExpectedError - section has bad meta data `fooNumber` field of
+      /* $FlowExpectedError[incompatible-type] - section has bad meta data `fooNumber` field of
        * type string */
       sections={sections}
     />

packages/react-native/Libraries/ReactNative/ReactFabricPublicInstance/ReactFabricHostComponent.js

@@ -58,12 +58,12 @@ export default class ReactFabricHostComponent implements NativeMethods {
   }
 
   blur() {
-    // $FlowFixMe - Error supressed during the migration of HostInstance to ReactNativeElement
+    // $FlowFixMe[incompatible-type] - Error supressed during the migration of HostInstance to ReactNativeElement
     TextInputState.blurTextInput(this);
   }
 
   focus() {
-    // $FlowFixMe - Error supressed during the migration of HostInstance to ReactNativeElement
+    // $FlowFixMe[incompatible-type] - Error supressed during the migration of HostInstance to ReactNativeElement
     TextInputState.focusTextInput(this);
   }
 

packages/react-native/Libraries/ReactNative/RendererImplementation.js

@@ -47,14 +47,14 @@ const getMethod: (<MethodName: $Keys<ReactFabricType>>(
   ) => ReactNativeType[MethodName]) = (getRenderer, methodName) => {
   let cachedImpl;
 
-  // $FlowExpectedError
+  // $FlowExpectedError[incompatible-type]
   return function (arg1, arg2, arg3, arg4, arg5, arg6) {
     if (cachedImpl == null) {
-      // $FlowExpectedError
+      // $FlowExpectedError[prop-missing]
       cachedImpl = getRenderer()[methodName];
     }
 
-    // $FlowExpectedError
+    // $FlowExpectedError[extra-arg]
     return cachedImpl(arg1, arg2, arg3, arg4, arg5);
   };
 };

packages/react-native/Libraries/Renderer/shims/ReactNativeViewConfigRegistry.js

@@ -7,7 +7,7 @@
  * @noformat
  * @nolint
  * @flow strict-local
- * @generated SignedSource<<83073425aa3f71ced2c8c51f25a25938>>
+ * @generated SignedSource<<1f7876c0dc0b05685a730513dc410236>>
  */
 
 'use strict';
@@ -82,6 +82,8 @@ export function register(name: string, callback: () => ViewConfig): string {
     typeof callback === 'function',
     'View config getter callback for component `%s` must be a function (received `%s`)',
     name,
+    /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+     * roll out. See https://fburl.com/workplace/5whu3i34. */
     callback === null ? 'null' : typeof callback,
   );
   viewConfigCallbacks.set(name, callback);

packages/react-native/Libraries/Share/Share.js

@@ -83,6 +83,8 @@ class Share {
     options?: ShareOptions = {},
   ): Promise<{action: string, activityType: ?string}> {
     invariant(
+      /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+       * roll out. See https://fburl.com/workplace/5whu3i34. */
       typeof content === 'object' && content !== null,
       'Content to share must be a valid object',
     );
@@ -91,6 +93,8 @@ class Share {
       'At least one of URL or message is required',
     );
     invariant(
+      /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+       * roll out. See https://fburl.com/workplace/5whu3i34. */
       typeof options === 'object' && options !== null,
       'Options must be a valid object',
     );

packages/react-native/Libraries/StyleSheet/__flowtests__/StyleSheet-flowtest.js

@@ -37,17 +37,17 @@ export function testGoodCompose() {
 }
 
 export function testBadCompose() {
-  // $FlowExpectedError - Incompatible type.
+  // $FlowExpectedError[incompatible-type]  - Incompatible type.
   (StyleSheet.compose(textStyle, textStyle): ImageStyleProp);
 
-  // $FlowExpectedError - Incompatible type.
+  // $FlowExpectedError[incompatible-type]  - Incompatible type.
   (StyleSheet.compose(
     // $FlowExpectedError - Incompatible type.
     [textStyle],
     null,
   ): ImageStyleProp);
 
-  // $FlowExpectedError - Incompatible type.
+  // $FlowExpectedError[incompatible-type]  - Incompatible type.
   (StyleSheet.compose(
     Math.random() < 0.5 ? textStyle : null,
     null,

packages/react-native/Libraries/StyleSheet/processFilter.js

@@ -69,9 +69,9 @@ export default function processFilter(
 
         if (amount != null) {
           const filterFunction = {};
-          // $FlowFixMe The key will be the correct one but flow can't see that.
+          // $FlowFixMe[prop-missing] The key will be the correct one but flow can't see that.
           filterFunction[camelizedName] = amount;
-          // $FlowFixMe The key will be the correct one but flow can't see that.
+          // $FlowFixMe[incompatible-type] The key will be the correct one but flow can't see that.
           result.push(filterFunction);
         } else {
           // If any primitive is invalid then apply none of the filters. This is how
@@ -85,7 +85,7 @@ export default function processFilter(
     for (const filterFunction of filter) {
       const [filterName, filterValue] = Object.entries(filterFunction)[0];
       if (filterName === 'dropShadow') {
-        // $FlowFixMe
+        // $FlowFixMe[incompatible-type]
         const dropShadow = parseDropShadow(filterValue);
         if (dropShadow == null) {
           return [];
@@ -96,9 +96,9 @@ export default function processFilter(
 
         if (amount != null) {
           const resultObject = {};
-          // $FlowFixMe
+          // $FlowFixMe[prop-missing]
           resultObject[filterName] = amount;
-          // $FlowFixMe
+          // $FlowFixMe[incompatible-type]
           result.push(resultObject);
         } else {
           // If any primitive is invalid then apply none of the filters. This is how

packages/react-native/Libraries/Utilities/HMRClient.js

@@ -165,6 +165,8 @@ const HMRClient: HMRClientNativeInterface = {
     // Moving to top gives errors due to NativeModules not being initialized
     const DevLoadingView = require('./DevLoadingView').default;
 
+    /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+     * roll out. See https://fburl.com/workplace/5whu3i34. */
     const serverHost = port !== null && port !== '' ? `${host}:${port}` : host;
 
     const serverScheme = scheme;

packages/react-native/Libraries/Utilities/deepFreezeAndThrowOnMutationInDev.js

@@ -33,6 +33,8 @@ function deepFreezeAndThrowOnMutationInDev<T: {...} | Array<mixed>>(
   if (__DEV__) {
     if (
       typeof object !== 'object' ||
+      /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+       * roll out. See https://fburl.com/workplace/5whu3i34. */
       object === null ||
       Object.isFrozen(object) ||
       Object.isSealed(object)

packages/react-native/Libraries/WebSocket/WebSocketInterceptor.js

@@ -232,6 +232,8 @@ const WebSocketInterceptor = {
 
   _arrayBufferToString(data: string): ArrayBuffer | string {
     const value = base64.toByteArray(data).buffer;
+    /* $FlowFixMe[invalid-compare] Error discovered during Constant Condition
+     * roll out. See https://fburl.com/workplace/5whu3i34. */
     if (value === undefined || value === null) {
       return '(no value)';
     }

packages/react-native/Libraries/vendor/emitter/__tests__/EventEmitter-test.js

@@ -106,27 +106,27 @@ describe('listeners', () => {
     }).not.toThrow();
 
     expect(() => {
-      // $FlowExpectedError
+      // $FlowExpectedError[incompatible-type] 
       emitter.addListener('A', null);
     }).toThrow();
 
     expect(() => {
-      // $FlowExpectedError
+      // $FlowExpectedError[incompatible-type] 
       emitter.addListener('A', undefined);
     }).toThrow();
 
     expect(() => {
-      // $FlowExpectedError
+      // $FlowExpectedError[incompatible-type] 
       emitter.addListener('A', 'abc');
     }).toThrow();
 
     expect(() => {
-      // $FlowExpectedError
+      // $FlowExpectedError[incompatible-type] 
       emitter.addListener('A', 123);
     }).toThrow();
 
     expect(() => {
-      // $FlowExpectedError
+      // $FlowExpectedError[incompatible-type] 
       emitter.addListener('A', 123);
     }).toThrow();
   });

packages/react-native/React/Base/RCTUtils.mm

@@ -415,7 +415,9 @@ CGSize RCTSwitchSize(void)
   static CGSize rctSwitchSize;
   static dispatch_once_t onceToken;
   dispatch_once(&onceToken, ^{
-    rctSwitchSize = [UISwitch new].intrinsicContentSize;
+    RCTUnsafeExecuteOnMainQueueSync(^{
+      rctSwitchSize = [UISwitch new].intrinsicContentSize;
+    });
   });
   return rctSwitchSize;
 }

packages/react-native/React/Fabric/Mounting/ComponentViews/VirtualView/RCTVirtualViewComponentView.mm

@@ -230,21 +230,34 @@ static BOOL sIsAccessibilityUsed = NO;
       scrollView.contentOffset.y,
       scrollView.frame.size.width,
       scrollView.frame.size.height);
+  const CGFloat visibleWidth = thresholdRect.size.width;
+  const CGFloat visibleHeight = thresholdRect.size.height;
+
   if (CGRectOverlaps(targetRect, thresholdRect)) {
     newMode = RCTVirtualViewModeVisible;
   } else {
     auto prerender = false;
     const CGFloat prerenderRatio = ReactNativeFeatureFlags::virtualViewPrerenderRatio();
     if (prerenderRatio > 0) {
-      thresholdRect = CGRectInset(
-          thresholdRect, -thresholdRect.size.width * prerenderRatio, -thresholdRect.size.height * prerenderRatio);
+      thresholdRect = CGRectInset(thresholdRect, -visibleWidth * prerenderRatio, -visibleHeight * prerenderRatio);
       prerender = CGRectOverlaps(targetRect, thresholdRect);
     }
     if (prerender) {
       newMode = RCTVirtualViewModePrerender;
     } else {
-      newMode = RCTVirtualViewModeHidden;
-      thresholdRect = CGRectZero;
+      const CGFloat hysteresisRatio = ReactNativeFeatureFlags::virtualViewHysteresisRatio();
+      if (_mode.has_value() && hysteresisRatio > 0) {
+        thresholdRect = CGRectInset(thresholdRect, -visibleWidth * hysteresisRatio, -visibleHeight * hysteresisRatio);
+        if (CGRectOverlaps(targetRect, thresholdRect)) {
+          newMode = _mode.value();
+        } else {
+          newMode = RCTVirtualViewModeHidden;
+          thresholdRect = CGRectZero;
+        }
+      } else {
+        newMode = RCTVirtualViewModeHidden;
+        thresholdRect = CGRectZero;
+      }
     }
   }
 

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -744,34 +744,6 @@ public abstract class com/facebook/react/bridge/GuardedRunnable : java/lang/Runn
 	public abstract fun runGuarded ()V
 }
 
-public final class com/facebook/react/bridge/Inspector {
-	public static final field Companion Lcom/facebook/react/bridge/Inspector$Companion;
-	public static final fun connect (ILcom/facebook/react/bridge/Inspector$RemoteConnection;)Lcom/facebook/react/bridge/Inspector$LocalConnection;
-	public static final fun getPages ()Ljava/util/List;
-}
-
-public final class com/facebook/react/bridge/Inspector$Companion {
-	public final fun connect (ILcom/facebook/react/bridge/Inspector$RemoteConnection;)Lcom/facebook/react/bridge/Inspector$LocalConnection;
-	public final fun getPages ()Ljava/util/List;
-}
-
-public final class com/facebook/react/bridge/Inspector$LocalConnection {
-	public final fun disconnect ()V
-	public final fun sendMessage (Ljava/lang/String;)V
-}
-
-public final class com/facebook/react/bridge/Inspector$Page {
-	public final fun getId ()I
-	public final fun getTitle ()Ljava/lang/String;
-	public final fun getVM ()Ljava/lang/String;
-	public fun toString ()Ljava/lang/String;
-}
-
-public abstract interface class com/facebook/react/bridge/Inspector$RemoteConnection {
-	public abstract fun onDisconnect ()V
-	public abstract fun onMessage (Ljava/lang/String;)V
-}
-
 public class com/facebook/react/bridge/JSApplicationCausedNativeException : java/lang/RuntimeException {
 	public fun <init> (Ljava/lang/String;)V
 	public fun <init> (Ljava/lang/String;Ljava/lang/Throwable;)V
@@ -1018,10 +990,6 @@ public abstract interface class com/facebook/react/bridge/NotThreadSafeBridgeIdl
 	public abstract fun onTransitionToBridgeIdle ()V
 }
 
-public abstract interface class com/facebook/react/bridge/OnBatchCompleteListener {
-	public abstract fun onBatchComplete ()V
-}
-
 public abstract interface class com/facebook/react/bridge/PerformanceCounter {
 	public abstract fun getPerformanceCounters ()Ljava/util/Map;
 	public abstract fun profileNextBatch ()V
@@ -1863,15 +1831,9 @@ public class com/facebook/react/defaults/DefaultReactActivityDelegate : com/face
 public final class com/facebook/react/defaults/DefaultReactHost {
 	public static final field INSTANCE Lcom/facebook/react/defaults/DefaultReactHost;
 	public static final fun getDefaultReactHost (Landroid/content/Context;Lcom/facebook/react/ReactNativeHost;Lcom/facebook/react/runtime/JSRuntimeFactory;)Lcom/facebook/react/ReactHost;
-	public static final fun getDefaultReactHost (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lcom/facebook/react/runtime/JSRuntimeFactory;ZLjava/util/List;)Lcom/facebook/react/ReactHost;
 	public static final fun getDefaultReactHost (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lcom/facebook/react/runtime/JSRuntimeFactory;ZLjava/util/List;Lkotlin/jvm/functions/Function1;Lcom/facebook/react/runtime/BindingsInstaller;)Lcom/facebook/react/ReactHost;
-	public static final fun getDefaultReactHost (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ZZLjava/util/List;)Lcom/facebook/react/ReactHost;
-	public static final fun getDefaultReactHost (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ZZLjava/util/List;Lkotlin/jvm/functions/Function1;Lcom/facebook/react/runtime/BindingsInstaller;)Lcom/facebook/react/ReactHost;
 	public static synthetic fun getDefaultReactHost$default (Landroid/content/Context;Lcom/facebook/react/ReactNativeHost;Lcom/facebook/react/runtime/JSRuntimeFactory;ILjava/lang/Object;)Lcom/facebook/react/ReactHost;
-	public static synthetic fun getDefaultReactHost$default (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lcom/facebook/react/runtime/JSRuntimeFactory;ZLjava/util/List;ILjava/lang/Object;)Lcom/facebook/react/ReactHost;
 	public static synthetic fun getDefaultReactHost$default (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lcom/facebook/react/runtime/JSRuntimeFactory;ZLjava/util/List;Lkotlin/jvm/functions/Function1;Lcom/facebook/react/runtime/BindingsInstaller;ILjava/lang/Object;)Lcom/facebook/react/ReactHost;
-	public static synthetic fun getDefaultReactHost$default (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ZZLjava/util/List;ILjava/lang/Object;)Lcom/facebook/react/ReactHost;
-	public static synthetic fun getDefaultReactHost$default (Landroid/content/Context;Ljava/util/List;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ZZLjava/util/List;Lkotlin/jvm/functions/Function1;Lcom/facebook/react/runtime/BindingsInstaller;ILjava/lang/Object;)Lcom/facebook/react/ReactHost;
 }
 
 public abstract class com/facebook/react/defaults/DefaultReactNativeHost : com/facebook/react/ReactNativeHost {
@@ -4368,7 +4330,6 @@ public class com/facebook/react/uimanager/UIManagerModule : com/facebook/react/b
 	public fun addRootView (Landroid/view/View;Lcom/facebook/react/bridge/WritableMap;)I
 	public fun addUIBlock (Lcom/facebook/react/uimanager/UIBlock;)V
 	public fun addUIManagerEventListener (Lcom/facebook/react/bridge/UIManagerListener;)V
-	public fun addUIManagerListener (Lcom/facebook/react/uimanager/UIManagerModuleListener;)V
 	public fun clearJSResponder ()V
 	public fun configureNextLayoutAnimation (Lcom/facebook/react/bridge/ReadableMap;Lcom/facebook/react/bridge/Callback;Lcom/facebook/react/bridge/Callback;)V
 	public static fun createConstants (Ljava/util/List;Ljava/util/Map;Ljava/util/Map;)Ljava/util/Map;
@@ -4405,7 +4366,6 @@ public class com/facebook/react/uimanager/UIManagerModule : com/facebook/react/b
 	public fun receiveEvent (ILjava/lang/String;Lcom/facebook/react/bridge/WritableMap;)V
 	public fun removeRootView (I)V
 	public fun removeUIManagerEventListener (Lcom/facebook/react/bridge/UIManagerListener;)V
-	public fun removeUIManagerListener (Lcom/facebook/react/uimanager/UIManagerModuleListener;)V
 	public fun resolveCustomDirectEventName (Ljava/lang/String;)Ljava/lang/String;
 	public fun resolveRootTagFromReactTag (I)I
 	public fun resolveView (I)Landroid/view/View;
@@ -5687,6 +5647,8 @@ public class com/facebook/react/views/scroll/ReactHorizontalScrollViewManager :
 	public fun flashScrollIndicators (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;)V
 	public synthetic fun flashScrollIndicators (Ljava/lang/Object;)V
 	public fun getName ()Ljava/lang/String;
+	public synthetic fun prepareToRecycleView (Lcom/facebook/react/uimanager/ThemedReactContext;Landroid/view/View;)Landroid/view/View;
+	protected fun prepareToRecycleView (Lcom/facebook/react/uimanager/ThemedReactContext;Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;)Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;
 	public synthetic fun receiveCommand (Landroid/view/View;ILcom/facebook/react/bridge/ReadableArray;)V
 	public synthetic fun receiveCommand (Landroid/view/View;Ljava/lang/String;Lcom/facebook/react/bridge/ReadableArray;)V
 	public fun receiveCommand (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;ILcom/facebook/react/bridge/ReadableArray;)V
@@ -5950,6 +5912,8 @@ public class com/facebook/react/views/scroll/ReactScrollViewManager : com/facebo
 	public fun getCommandsMap ()Ljava/util/Map;
 	public fun getExportedCustomDirectEventTypeConstants ()Ljava/util/Map;
 	public fun getName ()Ljava/lang/String;
+	public synthetic fun prepareToRecycleView (Lcom/facebook/react/uimanager/ThemedReactContext;Landroid/view/View;)Landroid/view/View;
+	protected fun prepareToRecycleView (Lcom/facebook/react/uimanager/ThemedReactContext;Lcom/facebook/react/views/scroll/ReactScrollView;)Lcom/facebook/react/views/scroll/ReactScrollView;
 	public synthetic fun receiveCommand (Landroid/view/View;ILcom/facebook/react/bridge/ReadableArray;)V
 	public synthetic fun receiveCommand (Landroid/view/View;Ljava/lang/String;Lcom/facebook/react/bridge/ReadableArray;)V
 	public fun receiveCommand (Lcom/facebook/react/views/scroll/ReactScrollView;ILcom/facebook/react/bridge/ReadableArray;)V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/Inspector.kt

@@ -1,78 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-package com.facebook.react.bridge
-
-import com.facebook.common.logging.FLog
-import com.facebook.jni.HybridData
-import com.facebook.proguard.annotations.DoNotStrip
-import com.facebook.react.common.ReactConstants
-
-@DoNotStrip
-public class Inspector
-private constructor(@Suppress("NoHungarianNotation") private val mHybridData: HybridData) {
-
-  private external fun getPagesNative(): Array<Page>
-
-  private external fun connectNative(pageId: Int, remote: RemoteConnection): LocalConnection?
-
-  @DoNotStrip
-  public class Page
-  private constructor(private val id: Int, private val title: String, private val vm: String) {
-    public fun getId(): Int = id
-
-    public fun getTitle(): String = title
-
-    public fun getVM(): String = vm
-
-    override fun toString(): String = "Page{id=$id, title='$title'}"
-  }
-
-  @DoNotStrip
-  public interface RemoteConnection {
-    @DoNotStrip public fun onMessage(message: String)
-
-    @DoNotStrip public fun onDisconnect()
-  }
-
-  @DoNotStrip
-  public class LocalConnection
-  private constructor(@Suppress("NoHungarianNotation") private val mHybridData: HybridData) {
-    public external fun sendMessage(message: String)
-
-    public external fun disconnect()
-  }
-
-  public companion object {
-    init {
-      ReactNativeJNISoLoader.staticInit()
-    }
-
-    @JvmStatic
-    public fun getPages(): List<Page> {
-      return try {
-        instance().getPagesNative().toList()
-      } catch (e: UnsatisfiedLinkError) {
-        FLog.e(ReactConstants.TAG, "Inspector doesn't work in open source yet", e)
-        emptyList()
-      }
-    }
-
-    @JvmStatic
-    public fun connect(pageId: Int, remote: RemoteConnection): LocalConnection {
-      return try {
-        instance().connectNative(pageId, remote)
-            ?: throw IllegalStateException("Can't open failed connection")
-      } catch (e: UnsatisfiedLinkError) {
-        FLog.e(ReactConstants.TAG, "Inspector doesn't work in open source yet", e)
-        throw RuntimeException(e)
-      }
-    }
-
-    @JvmStatic private external fun instance(): Inspector
-  }
-}

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/JavaMethodWrapper.kt

@@ -189,7 +189,7 @@ internal class JavaMethodWrapper(
           }
 
       if (jsArgumentsNeeded != parameters.size()) {
-        throw NativeArgumentsParseException(
+        throw JSApplicationCausedNativeException(
             "$traceName got ${parameters.size()} arguments, expected $jsArgumentsNeeded"
         )
       }
@@ -208,7 +208,7 @@ internal class JavaMethodWrapper(
           i++
         }
       } catch (e: UnexpectedNativeTypeException) {
-        throw NativeArgumentsParseException(
+        throw JSApplicationCausedNativeException(
             "${e.message} (constructing arguments for $traceName at argument index ${
               getAffectedRange(
                   jsArgumentsConsumed,
@@ -218,7 +218,7 @@ internal class JavaMethodWrapper(
             e,
         )
       } catch (e: NullPointerException) {
-        throw NativeArgumentsParseException(
+        throw JSApplicationCausedNativeException(
             "${e.message} (constructing arguments for $traceName at argument index ${
               getAffectedRange(
                   jsArgumentsConsumed,

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/NativeArgumentsParseException.kt

@@ -1,34 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-package com.facebook.react.bridge
-
-import com.facebook.react.common.annotations.internal.LegacyArchitecture
-import com.facebook.react.common.annotations.internal.LegacyArchitectureLogLevel
-import com.facebook.react.common.annotations.internal.LegacyArchitectureLogger
-
-/** Exception thrown when a native module method call receives unexpected arguments from JS. */
-@LegacyArchitecture(logLevel = LegacyArchitectureLogLevel.ERROR)
-@Deprecated(
-    message = "This class is part of Legacy Architecture and will be removed in a future release",
-    level = DeprecationLevel.WARNING,
-)
-internal class NativeArgumentsParseException : JSApplicationCausedNativeException {
-
-  constructor(detailMessage: String) : super(detailMessage)
-
-  constructor(detailMessage: String, throwable: Throwable?) : super(detailMessage, throwable)
-
-  private companion object {
-    init {
-      LegacyArchitectureLogger.assertLegacyArchitecture(
-          "NativeArgumentsParseException",
-          logLevel = LegacyArchitectureLogLevel.ERROR,
-      )
-    }
-  }
-}

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/OnBatchCompleteListener.kt

@@ -16,6 +16,6 @@ import com.facebook.react.common.annotations.internal.LegacyArchitectureLogLevel
     message = "This class is part of Legacy Architecture and will be removed in a future release",
     level = DeprecationLevel.WARNING,
 )
-public fun interface OnBatchCompleteListener {
-  public fun onBatchComplete()
+internal fun interface OnBatchCompleteListener {
+  fun onBatchComplete()
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactNativeJNISoLoader.kt

@@ -7,8 +7,10 @@
 
 package com.facebook.react.bridge
 
+import com.facebook.react.common.annotations.internal.InteropLegacyArchitecture
 import com.facebook.soloader.SoLoader
 
+@InteropLegacyArchitecture
 internal object ReactNativeJNISoLoader {
 
   @JvmStatic

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/defaults/DefaultReactHost.kt

@@ -35,50 +35,6 @@ import java.lang.Exception
 public object DefaultReactHost {
   private var reactHost: ReactHost? = null
 
-  /**
-   * Util function to create a default [ReactHost] to be used in your application. This method is
-   * used by the New App template.
-   *
-   * @param context the Android [Context] to use for creating the [ReactHost]
-   * @param packageList the list of [ReactPackage]s to use for creating the [ReactHost]
-   * @param jsMainModulePath the path to your app's main module on Metro. Usually `index` or
-   *   `index.<platform>`
-   * @param jsBundleAssetPath the path to the JS bundle relative to the assets directory. Will be
-   *   composed in a `asset://...` URL
-   * @param jsBundleFilePath the path to the JS bundle on the filesystem. Will be composed in a
-   *   `file://...` URL
-   * @param jsRuntimeFactory the JS engine to use for executing [ReactHost], default to Hermes.
-   * @param useDevSupport whether to enable dev support, default to ReactBuildConfig.DEBUG.
-   * @param cxxReactPackageProviders a list of cxxreactpackage providers (to register c++ turbo
-   *   modules)
-   *
-   * TODO(T186951312): Should this be @UnstableReactNativeAPI?
-   */
-  @OptIn(UnstableReactNativeAPI::class)
-  @JvmStatic
-  public fun getDefaultReactHost(
-      context: Context,
-      packageList: List<ReactPackage>,
-      jsMainModulePath: String = "index",
-      jsBundleAssetPath: String = "index",
-      jsBundleFilePath: String? = null,
-      jsRuntimeFactory: JSRuntimeFactory? = null,
-      useDevSupport: Boolean = ReactBuildConfig.DEBUG,
-      cxxReactPackageProviders: List<(ReactContext) -> CxxReactPackage> = emptyList(),
-  ): ReactHost =
-      getDefaultReactHost(
-          context,
-          packageList,
-          jsMainModulePath,
-          jsBundleAssetPath,
-          jsBundleFilePath,
-          jsRuntimeFactory,
-          useDevSupport,
-          cxxReactPackageProviders,
-          { throw it },
-          null,
-      )
-
   /**
    * Util function to create a default [ReactHost] to be used in your application. This method is
    * used by the New App template.
@@ -154,129 +110,6 @@ public object DefaultReactHost {
     return reactHost as ReactHost
   }
 
-  /**
-   * Util function to create a default [ReactHost] to be used in your application. This method is
-   * used by the New App template.
-   *
-   * @param context the Android [Context] to use for creating the [ReactHost]
-   * @param packageList the list of [ReactPackage]s to use for creating the [ReactHost]
-   * @param jsMainModulePath the path to your app's main module on Metro. Usually `index` or
-   *   `index.<platform>`
-   * @param jsBundleAssetPath the path to the JS bundle relative to the assets directory. Will be
-   *   composed in a `asset://...` URL
-   * @param jsBundleFilePath the path to the JS bundle on the filesystem. Will be composed in a
-   *   `file://...` URL
-   * @param isHermesEnabled whether to use Hermes as the JS engine, default to true.
-   * @param useDevSupport whether to enable dev support, default to ReactBuildConfig.DEBUG.
-   * @param cxxReactPackageProviders a list of cxxreactpackage providers (to register c++ turbo
-   *   modules)
-   * @param exceptionHandler Callback that can be used by React Native host applications to react to
-   *   exceptions thrown by the internals of React Native.
-   * @param bindingsInstaller that can be used for installing bindings.
-   */
-  @Deprecated(
-      message = "Use `getDefaultReactHost`  with `jsRuntimeFactory` instead",
-      replaceWith =
-          ReplaceWith(
-              """
-      fun getDefaultReactHost(
-        context: Context,
-        packageList: List<ReactPackage>,
-        jsMainModulePath: String,
-        jsBundleAssetPath: String,
-        jsBundleFilePath: String?,
-        jsRuntimeFactory: JSRuntimeFactory?,
-        useDevSupport: Boolean,
-        cxxReactPackageProviders: List<(ReactContext) -> CxxReactPackage>,
-        exceptionHandler: (Exception) -> Unit,
-        bindingsInstaller: BindingsInstaller?,
-      ): ReactHost
-    """
-          ),
-  )
-  @JvmStatic
-  public fun getDefaultReactHost(
-      context: Context,
-      packageList: List<ReactPackage>,
-      jsMainModulePath: String = "index",
-      jsBundleAssetPath: String = "index",
-      jsBundleFilePath: String? = null,
-      isHermesEnabled: Boolean = true,
-      useDevSupport: Boolean = ReactBuildConfig.DEBUG,
-      cxxReactPackageProviders: List<(ReactContext) -> CxxReactPackage> = emptyList(),
-      exceptionHandler: (Exception) -> Unit = { throw it },
-      bindingsInstaller: BindingsInstaller? = null,
-  ): ReactHost =
-      getDefaultReactHost(
-          context,
-          packageList,
-          jsMainModulePath,
-          jsBundleAssetPath,
-          jsBundleFilePath,
-          HermesInstance(),
-          useDevSupport,
-          cxxReactPackageProviders,
-          exceptionHandler,
-          bindingsInstaller,
-      )
-
-  /**
-   * Util function to create a default [ReactHost] to be used in your application. This method is
-   * used by the New App template.
-   *
-   * @param context the Android [Context] to use for creating the [ReactHost]
-   * @param packageList the list of [ReactPackage]s to use for creating the [ReactHost]
-   * @param jsMainModulePath the path to your app's main module on Metro. Usually `index` or
-   *   `index.<platform>`
-   * @param jsBundleAssetPath the path to the JS bundle relative to the assets directory. Will be
-   *   composed in a `asset://...` URL
-   * @param jsBundleFilePath the path to the JS bundle on the filesystem. Will be composed in a
-   *   `file://...` URL
-   * @param isHermesEnabled whether to use Hermes as the JS engine, default to true.
-   * @param useDevSupport whether to enable dev support, default to ReactBuildConfig.DEBUG.
-   * @param cxxReactPackageProviders a list of cxxreactpackage providers (to register c++ turbo
-   *   modules)
-   */
-  @Deprecated(
-      message = "Use `getDefaultReactHost`  with `jsRuntimeFactory` instead",
-      replaceWith =
-          ReplaceWith(
-              """
-      fun getDefaultReactHost(
-        context: Context,
-        packageList: List<ReactPackage>,
-        jsMainModulePath: String,
-        jsBundleAssetPath: String,
-        jsBundleFilePath: String?,
-        jsRuntimeFactory: JSRuntimeFactory?,
-        useDevSupport: Boolean,
-        cxxReactPackageProviders: List<(ReactContext) -> CxxReactPackage>,
-      ): ReactHost
-    """
-          ),
-  )
-  @JvmStatic
-  public fun getDefaultReactHost(
-      context: Context,
-      packageList: List<ReactPackage>,
-      jsMainModulePath: String = "index",
-      jsBundleAssetPath: String = "index",
-      jsBundleFilePath: String? = null,
-      isHermesEnabled: Boolean = true,
-      useDevSupport: Boolean = ReactBuildConfig.DEBUG,
-      cxxReactPackageProviders: List<(ReactContext) -> CxxReactPackage> = emptyList(),
-  ): ReactHost =
-      getDefaultReactHost(
-          context,
-          packageList,
-          jsMainModulePath,
-          jsBundleAssetPath,
-          jsBundleFilePath,
-          HermesInstance(),
-          useDevSupport,
-          cxxReactPackageProviders,
-      )
-
   /**
    * Util function to create a default [ReactHost] to be used in your application. This method is
    * used by the New App template.

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevSupportManagerBase.kt

@@ -927,7 +927,7 @@ public abstract class DevSupportManagerBase(
     devServerHelper.openDebugger(
         currentReactContext,
         applicationContext.getString(R.string.catalyst_open_debugger_error),
-        ChromeDevToolsViewKeys.Performance.value,
+        null,
     )
   }
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<f162c19a6742ecadd171500ccb918f4b>>
+ * @generated SignedSource<<34c12f5a31aab5bfb874953f1beefef1>>
  */
 
 /**
@@ -258,6 +258,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableViewRecycling(): Boolean = accessor.enableViewRecycling()
 
+  /**
+   * Enables View Recycling for <ScrollView> via ReactViewGroup/ReactViewManager.
+   */
+  @JvmStatic
+  public fun enableViewRecyclingForScrollView(): Boolean = accessor.enableViewRecyclingForScrollView()
+
   /**
    * Enables View Recycling for <Text> via ReactTextView/ReactTextViewManager.
    */
@@ -426,6 +432,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun useTurboModules(): Boolean = accessor.useTurboModules()
 
+  /**
+   * Sets a hysteresis window for transition between prerender and hidden modes.
+   */
+  @JvmStatic
+  public fun virtualViewHysteresisRatio(): Double = accessor.virtualViewHysteresisRatio()
+
   /**
    * Initial prerender ratio for VirtualView.
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<51bb91fd70ba266c01bf46b3ca237ad5>>
+ * @generated SignedSource<<392da016e0bf4193b72c44a508811e10>>
  */
 
 /**
@@ -58,6 +58,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var enableResourceTimingAPICache: Boolean? = null
   private var enableViewCullingCache: Boolean? = null
   private var enableViewRecyclingCache: Boolean? = null
+  private var enableViewRecyclingForScrollViewCache: Boolean? = null
   private var enableViewRecyclingForTextCache: Boolean? = null
   private var enableViewRecyclingForViewCache: Boolean? = null
   private var enableVirtualViewDebugFeaturesCache: Boolean? = null
@@ -86,6 +87,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var useShadowNodeStateOnCloneCache: Boolean? = null
   private var useTurboModuleInteropCache: Boolean? = null
   private var useTurboModulesCache: Boolean? = null
+  private var virtualViewHysteresisRatioCache: Double? = null
   private var virtualViewPrerenderRatioCache: Double? = null
 
   override fun commonTestFlag(): Boolean {
@@ -430,6 +432,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun enableViewRecyclingForScrollView(): Boolean {
+    var cached = enableViewRecyclingForScrollViewCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableViewRecyclingForScrollView()
+      enableViewRecyclingForScrollViewCache = cached
+    }
+    return cached
+  }
+
   override fun enableViewRecyclingForText(): Boolean {
     var cached = enableViewRecyclingForTextCache
     if (cached == null) {
@@ -682,6 +693,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun virtualViewHysteresisRatio(): Double {
+    var cached = virtualViewHysteresisRatioCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.virtualViewHysteresisRatio()
+      virtualViewHysteresisRatioCache = cached
+    }
+    return cached
+  }
+
   override fun virtualViewPrerenderRatio(): Double {
     var cached = virtualViewPrerenderRatioCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<d4a1d4510264580e2f1436b05f1c2f0e>>
+ * @generated SignedSource<<a0453230524ebca2bfb8fad656a6f54a>>
  */
 
 /**
@@ -104,6 +104,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableViewRecycling(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun enableViewRecyclingForScrollView(): Boolean
+
   @DoNotStrip @JvmStatic public external fun enableViewRecyclingForText(): Boolean
 
   @DoNotStrip @JvmStatic public external fun enableViewRecyclingForView(): Boolean
@@ -160,6 +162,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun useTurboModules(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun virtualViewHysteresisRatio(): Double
+
   @DoNotStrip @JvmStatic public external fun virtualViewPrerenderRatio(): Double
 
   @DoNotStrip @JvmStatic public external fun override(provider: Any)

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<4cc61b5f71805589fa91abbdefb5eade>>
+ * @generated SignedSource<<719706a983a073b6c286c49d993f7f80>>
  */
 
 /**
@@ -99,6 +99,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableViewRecycling(): Boolean = false
 
+  override fun enableViewRecyclingForScrollView(): Boolean = false
+
   override fun enableViewRecyclingForText(): Boolean = true
 
   override fun enableViewRecyclingForView(): Boolean = true
@@ -139,15 +141,15 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun useFabricInterop(): Boolean = true
 
-  override fun useNativeEqualsInNativeReadableArrayAndroid(): Boolean = false
+  override fun useNativeEqualsInNativeReadableArrayAndroid(): Boolean = true
 
-  override fun useNativeTransformHelperAndroid(): Boolean = false
+  override fun useNativeTransformHelperAndroid(): Boolean = true
 
   override fun useNativeViewConfigsInBridgelessMode(): Boolean = false
 
   override fun useOptimizedEventBatchingOnAndroid(): Boolean = false
 
-  override fun useRawPropsJsiValue(): Boolean = false
+  override fun useRawPropsJsiValue(): Boolean = true
 
   override fun useShadowNodeStateOnClone(): Boolean = false
 
@@ -155,5 +157,7 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun useTurboModules(): Boolean = false
 
+  override fun virtualViewHysteresisRatio(): Double = 0.0
+
   override fun virtualViewPrerenderRatio(): Double = 5.0
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<78c9ee8f53273560de6b75719e317273>>
+ * @generated SignedSource<<594815ba6a984c460ab8bddd91c5cae2>>
  */
 
 /**
@@ -62,6 +62,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var enableResourceTimingAPICache: Boolean? = null
   private var enableViewCullingCache: Boolean? = null
   private var enableViewRecyclingCache: Boolean? = null
+  private var enableViewRecyclingForScrollViewCache: Boolean? = null
   private var enableViewRecyclingForTextCache: Boolean? = null
   private var enableViewRecyclingForViewCache: Boolean? = null
   private var enableVirtualViewDebugFeaturesCache: Boolean? = null
@@ -90,6 +91,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var useShadowNodeStateOnCloneCache: Boolean? = null
   private var useTurboModuleInteropCache: Boolean? = null
   private var useTurboModulesCache: Boolean? = null
+  private var virtualViewHysteresisRatioCache: Double? = null
   private var virtualViewPrerenderRatioCache: Double? = null
 
   override fun commonTestFlag(): Boolean {
@@ -472,6 +474,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun enableViewRecyclingForScrollView(): Boolean {
+    var cached = enableViewRecyclingForScrollViewCache
+    if (cached == null) {
+      cached = currentProvider.enableViewRecyclingForScrollView()
+      accessedFeatureFlags.add("enableViewRecyclingForScrollView")
+      enableViewRecyclingForScrollViewCache = cached
+    }
+    return cached
+  }
+
   override fun enableViewRecyclingForText(): Boolean {
     var cached = enableViewRecyclingForTextCache
     if (cached == null) {
@@ -752,6 +764,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun virtualViewHysteresisRatio(): Double {
+    var cached = virtualViewHysteresisRatioCache
+    if (cached == null) {
+      cached = currentProvider.virtualViewHysteresisRatio()
+      accessedFeatureFlags.add("virtualViewHysteresisRatio")
+      virtualViewHysteresisRatioCache = cached
+    }
+    return cached
+  }
+
   override fun virtualViewPrerenderRatio(): Double {
     var cached = virtualViewPrerenderRatioCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsOverrides_RNOSS_Experimental_Android.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<1f89971ab4d5b2ee27ace3a3c8da78cf>>
+ * @generated SignedSource<<4feeb3c1789d8169dd93bee7ae1ff1ac>>
  */
 
 /**
@@ -26,8 +26,4 @@ public open class ReactNativeFeatureFlagsOverrides_RNOSS_Experimental_Android :
   override fun enableAccessibilityOrder(): Boolean = true
 
   override fun preventShadowTreeCommitExhaustion(): Boolean = true
-
-  override fun useNativeEqualsInNativeReadableArrayAndroid(): Boolean = true
-
-  override fun useNativeTransformHelperAndroid(): Boolean = true
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<3db9f160e7221eb9c7660a3e93da0f40>>
+ * @generated SignedSource<<dfbd5e84392f1fda0e68324582c328b2>>
  */
 
 /**
@@ -99,6 +99,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableViewRecycling(): Boolean
 
+  @DoNotStrip public fun enableViewRecyclingForScrollView(): Boolean
+
   @DoNotStrip public fun enableViewRecyclingForText(): Boolean
 
   @DoNotStrip public fun enableViewRecyclingForView(): Boolean
@@ -155,5 +157,7 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun useTurboModules(): Boolean
 
+  @DoNotStrip public fun virtualViewHysteresisRatio(): Double
+
   @DoNotStrip public fun virtualViewPrerenderRatio(): Double
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactHostInspectorTarget.kt

@@ -34,6 +34,12 @@ internal class ReactHostInspectorTarget(reactHostImpl: ReactHostImpl) :
 
   external fun sendDebuggerResumeCommand()
 
+  external fun startBackgroundTrace(): Boolean
+
+  external fun stopAndStashBackgroundTrace()
+
+  external fun stopAndDiscardBackgroundTrace()
+
   override fun addPerfMonitorListener(listener: PerfMonitorUpdateListener) {
     perfMonitorListeners.add(listener)
   }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java

@@ -52,7 +52,6 @@ import com.facebook.react.uimanager.events.RCTEventEmitter;
 import com.facebook.react.uimanager.internal.LegacyArchitectureShadowNodeLogger;
 import com.facebook.systrace.Systrace;
 import com.facebook.systrace.SystraceMessage;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -117,7 +116,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule
   private final ViewManagerRegistry mViewManagerRegistry;
   private final UIImplementation mUIImplementation;
   private final MemoryTrimCallback mMemoryTrimCallback = new MemoryTrimCallback();
-  private final List<UIManagerModuleListener> mListeners = new ArrayList<>();
   private final CopyOnWriteArrayList<UIManagerListener> mUIManagerListeners =
       new CopyOnWriteArrayList<>();
 
@@ -687,9 +685,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule
     SystraceMessage.beginSection(Systrace.TRACE_TAG_REACT, "onBatchCompleteUI")
         .arg("BatchId", batchId)
         .flush();
-    for (UIManagerModuleListener listener : mListeners) {
-      listener.willDispatchViewUpdates(this);
-    }
     for (UIManagerListener listener : mUIManagerListeners) {
       listener.willDispatchViewUpdates(this);
     }
@@ -757,16 +752,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule
     mUIImplementation.prependUIBlock(block);
   }
 
-  @Deprecated
-  public void addUIManagerListener(UIManagerModuleListener listener) {
-    mListeners.add(listener);
-  }
-
-  @Deprecated
-  public void removeUIManagerListener(UIManagerModuleListener listener) {
-    mListeners.remove(listener);
-  }
-
   public void addUIManagerEventListener(UIManagerListener listener) {
     mUIManagerListeners.add(listener);
   }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModuleListener.kt

@@ -1,24 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-@file:Suppress("DEPRECATION")
-
-package com.facebook.react.uimanager
-
-import com.facebook.react.common.annotations.internal.LegacyArchitecture
-import com.facebook.react.common.annotations.internal.LegacyArchitectureLogLevel
-
-/** Listener used to hook into the UIManager update process. */
-@Deprecated("Use UIManagerListener instead. This will be deleted in some future release.")
-@LegacyArchitecture(logLevel = LegacyArchitectureLogLevel.ERROR)
-internal interface UIManagerModuleListener {
-  /**
-   * Called right before view updates are dispatched at the end of a batch. This is useful if a
-   * module needs to add UIBlocks to the queue before it is flushed.
-   */
-  fun willDispatchViewUpdates(uiManager: UIManagerModule)
-}

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewManager.java

@@ -54,7 +54,7 @@ public abstract class ViewManager<T extends View, C extends ReactShadowNode>
    * null signals that View Recycling is disabled. `enableViewRecycling` must be explicitly called
    * in a concrete constructor to enable View Recycling per ViewManager.
    */
-  @Nullable private HashMap<Integer, Stack<T>> mRecyclableViews = null;
+  @Nullable private Map<Integer, Stack<T>> mRecyclableViews = null;
 
   public ViewManager() {
     super(null);

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java

@@ -96,8 +96,10 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
   private final OnScrollDispatchHelper mOnScrollDispatchHelper = new OnScrollDispatchHelper();
   private final @Nullable OverScroller mScroller;
   private final VelocityHelper mVelocityHelper = new VelocityHelper();
-  private final Rect mOverflowInset = new Rect();
+  private final Rect mTempRect = new Rect();
+  private final ValueAnimator DEFAULT_FLING_ANIMATOR = ObjectAnimator.ofInt(this, "scrollX", 0, 0);
 
+  private Rect mOverflowInset = new Rect();
   private boolean mActivelyScrolling;
   private @Nullable Rect mClippingRect;
   private Overflow mOverflow = Overflow.SCROLL;
@@ -118,11 +120,10 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
   private boolean mSnapToEnd = true;
   private int mSnapToAlignment = SNAP_ALIGNMENT_DISABLED;
   private boolean mPagedArrowScrolling = false;
-  private int pendingContentOffsetX = UNSET_CONTENT_OFFSET;
-  private int pendingContentOffsetY = UNSET_CONTENT_OFFSET;
+  private int mPendingContentOffsetX = UNSET_CONTENT_OFFSET;
+  private int mPendingContentOffsetY = UNSET_CONTENT_OFFSET;
   private @Nullable StateWrapper mStateWrapper = null;
-  private final ReactScrollViewScrollState mReactScrollViewScrollState;
-  private final ValueAnimator DEFAULT_FLING_ANIMATOR = ObjectAnimator.ofInt(this, "scrollX", 0, 0);
+  private ReactScrollViewScrollState mReactScrollViewScrollState;
   private PointerEvents mPointerEvents = PointerEvents.AUTO;
   private long mLastScrollDispatchTime = 0;
   private int mScrollEventThrottle = 0;
@@ -131,8 +132,6 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
   private int mFadingEdgeLengthStart = 0;
   private int mFadingEdgeLengthEnd = 0;
 
-  private final Rect mTempRect = new Rect();
-
   public ReactHorizontalScrollView(Context context) {
     this(context, null);
   }
@@ -144,12 +143,67 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
     ViewCompat.setAccessibilityDelegate(this, new ReactScrollViewAccessibilityDelegate());
 
     mScroller = getOverScrollerFromParent();
-    mReactScrollViewScrollState = new ReactScrollViewScrollState();
 
     setOnHierarchyChangeListener(this);
     setClipChildren(false);
+    initView();
   }
 
+  /**
+   * Set all default values here as opposed to in the constructor or field defaults. It is important
+   * that these properties are set during the constructor, but also on-demand whenever an existing
+   * ReactTextView is recycled.
+   */
+  private void initView() {
+    mOverflowInset = new Rect();
+    mActivelyScrolling = false;
+    mClippingRect = null;
+    mOverflow = Overflow.SCROLL;
+    mDragging = false;
+    mPagingEnabled = false;
+    mPostTouchRunnable = null;
+    mRemoveClippedSubviews = false;
+    mScrollEnabled = true;
+    mSendMomentumEvents = false;
+    mFpsListener = null;
+    mScrollPerfTag = null;
+    mEndBackground = null;
+    mEndFillColor = Color.TRANSPARENT;
+    mDisableIntervalMomentum = false;
+    mSnapInterval = 0;
+    mSnapOffsets = null;
+    mSnapToStart = true;
+    mSnapToEnd = true;
+    mSnapToAlignment = SNAP_ALIGNMENT_DISABLED;
+    mPagedArrowScrolling = false;
+    mPendingContentOffsetX = UNSET_CONTENT_OFFSET;
+    mPendingContentOffsetY = UNSET_CONTENT_OFFSET;
+    mStateWrapper = null;
+    mReactScrollViewScrollState = new ReactScrollViewScrollState();
+
+    mPointerEvents = PointerEvents.AUTO;
+    mLastScrollDispatchTime = 0;
+    mScrollEventThrottle = 0;
+    mContentView = null;
+    mMaintainVisibleContentPositionHelper = null;
+    mFadingEdgeLengthStart = 0;
+    mFadingEdgeLengthEnd = 0;
+  }
+
+  /* package */ void recycleView() {
+    // Set default field values
+    initView();
+
+    // If the view is still attached to a parent, we need to remove it from the parent
+    // before we can recycle it.
+    if (getParent() != null) {
+      ((ViewGroup) getParent()).removeView(this);
+    }
+    updateView();
+  }
+
+  private void updateView() {}
+
   @Override
   public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
     super.onInitializeAccessibilityNodeInfo(info);
@@ -441,9 +495,9 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
       // If a "pending" content offset value has been set, we restore that value.
       // Upon call to scrollTo, the "pending" values will be re-set.
       int scrollToX =
-          pendingContentOffsetX != UNSET_CONTENT_OFFSET ? pendingContentOffsetX : getScrollX();
+          mPendingContentOffsetX != UNSET_CONTENT_OFFSET ? mPendingContentOffsetX : getScrollX();
       int scrollToY =
-          pendingContentOffsetY != UNSET_CONTENT_OFFSET ? pendingContentOffsetY : getScrollY();
+          mPendingContentOffsetY != UNSET_CONTENT_OFFSET ? mPendingContentOffsetY : getScrollY();
       scrollTo(scrollToX, scrollToY);
     }
 
@@ -1459,11 +1513,11 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
     }
 
     if (isContentReady()) {
-      pendingContentOffsetX = UNSET_CONTENT_OFFSET;
-      pendingContentOffsetY = UNSET_CONTENT_OFFSET;
+      mPendingContentOffsetX = UNSET_CONTENT_OFFSET;
+      mPendingContentOffsetY = UNSET_CONTENT_OFFSET;
     } else {
-      pendingContentOffsetX = x;
-      pendingContentOffsetY = y;
+      mPendingContentOffsetX = x;
+      mPendingContentOffsetY = y;
     }
   }
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.kt

@@ -14,6 +14,7 @@ import com.facebook.react.bridge.ReadableArray
 import com.facebook.react.bridge.ReadableMap
 import com.facebook.react.bridge.ReadableType
 import com.facebook.react.bridge.RetryableMountingLayerException
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
 import com.facebook.react.module.annotations.ReactModule
 import com.facebook.react.uimanager.BackgroundStyleApplicator.setBorderColor
 import com.facebook.react.uimanager.BackgroundStyleApplicator.setBorderRadius
@@ -55,6 +56,23 @@ public open class ReactHorizontalScrollViewManager
 @JvmOverloads
 constructor(private val fpsListener: FpsListener? = null) :
     ViewGroupManager<ReactHorizontalScrollView>(), ScrollCommandHandler<ReactHorizontalScrollView> {
+  init {
+    if (ReactNativeFeatureFlags.enableViewRecyclingForScrollView()) {
+      setupViewRecycling()
+    }
+  }
+
+  override fun prepareToRecycleView(
+      reactContext: ThemedReactContext,
+      view: ReactHorizontalScrollView,
+  ): ReactHorizontalScrollView? {
+    // BaseViewManager
+    val preparedView = super.prepareToRecycleView(reactContext, view)
+    if (preparedView != null) {
+      preparedView.recycleView()
+    }
+    return preparedView
+  }
 
   override fun getName(): String = REACT_CLASS
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollView.java

@@ -96,43 +96,41 @@ public class ReactScrollView extends ScrollView
   private final @Nullable OverScroller mScroller;
   private final VelocityHelper mVelocityHelper = new VelocityHelper();
   private final Rect mTempRect = new Rect();
-  private final Rect mOverflowInset = new Rect();
+  private final ValueAnimator DEFAULT_FLING_ANIMATOR = ObjectAnimator.ofInt(this, "scrollY", 0, 0);
 
+  private Rect mOverflowInset;
   private @Nullable VirtualViewContainerState mVirtualViewContainerState;
   private boolean mActivelyScrolling;
   private @Nullable Rect mClippingRect;
-  private Overflow mOverflow = Overflow.SCROLL;
+  private Overflow mOverflow;
   private boolean mDragging;
-  private boolean mPagingEnabled = false;
+  private boolean mPagingEnabled;
   private @Nullable Runnable mPostTouchRunnable;
   private boolean mRemoveClippedSubviews;
-  private boolean mScrollEnabled = true;
+  private boolean mScrollEnabled;
   private boolean mSendMomentumEvents;
-  private @Nullable FpsListener mFpsListener = null;
+  private @Nullable FpsListener mFpsListener;
   private @Nullable String mScrollPerfTag;
   private @Nullable Drawable mEndBackground;
-  private int mEndFillColor = Color.TRANSPARENT;
-  private boolean mDisableIntervalMomentum = false;
-  private int mSnapInterval = 0;
+  private int mEndFillColor;
+  private boolean mDisableIntervalMomentum;
+  private int mSnapInterval;
   private @Nullable List<Integer> mSnapOffsets;
-  private boolean mSnapToStart = true;
-  private boolean mSnapToEnd = true;
-  private int mSnapToAlignment = SNAP_ALIGNMENT_DISABLED;
+  private boolean mSnapToStart;
+  private boolean mSnapToEnd;
+  private int mSnapToAlignment;
   private @Nullable View mContentView;
-  private @Nullable ReadableMap mCurrentContentOffset = null;
-  private int pendingContentOffsetX = UNSET_CONTENT_OFFSET;
-  private int pendingContentOffsetY = UNSET_CONTENT_OFFSET;
-  private @Nullable StateWrapper mStateWrapper = null;
-  private final ReactScrollViewScrollState mReactScrollViewScrollState =
-      new ReactScrollViewScrollState();
-  private final ValueAnimator DEFAULT_FLING_ANIMATOR = ObjectAnimator.ofInt(this, "scrollY", 0, 0);
-  private PointerEvents mPointerEvents = PointerEvents.AUTO;
-  private long mLastScrollDispatchTime = 0;
-  private int mScrollEventThrottle = 0;
-  private @Nullable MaintainVisibleScrollPositionHelper mMaintainVisibleContentPositionHelper =
-      null;
-  private int mFadingEdgeLengthStart = 0;
-  private int mFadingEdgeLengthEnd = 0;
+  private @Nullable ReadableMap mCurrentContentOffset;
+  private int mPendingContentOffsetX;
+  private int mPendingContentOffsetY;
+  private @Nullable StateWrapper mStateWrapper;
+  private ReactScrollViewScrollState mReactScrollViewScrollState;
+  private PointerEvents mPointerEvents;
+  private long mLastScrollDispatchTime;
+  private int mScrollEventThrottle;
+  private @Nullable MaintainVisibleScrollPositionHelper mMaintainVisibleContentPositionHelper;
+  private int mFadingEdgeLengthStart;
+  private int mFadingEdgeLengthEnd;
 
   public ReactScrollView(Context context) {
     this(context, null);
@@ -148,8 +146,64 @@ public class ReactScrollView extends ScrollView
     setClipChildren(false);
 
     ViewCompat.setAccessibilityDelegate(this, new ReactScrollViewAccessibilityDelegate());
+    initView();
   }
 
+  /**
+   * Set all default values here as opposed to in the constructor or field defaults. It is important
+   * that these properties are set during the constructor, but also on-demand whenever an existing
+   * ReactTextView is recycled.
+   */
+  private void initView() {
+    mOverflowInset = new Rect();
+    mVirtualViewContainerState = null;
+    mActivelyScrolling = false;
+    mClippingRect = null;
+    mOverflow = Overflow.SCROLL;
+    mDragging = false;
+    mPagingEnabled = false;
+    mPostTouchRunnable = null;
+    mRemoveClippedSubviews = false;
+    mScrollEnabled = true;
+    mSendMomentumEvents = false;
+    mFpsListener = null;
+    mScrollPerfTag = null;
+    mEndBackground = null;
+    mEndFillColor = Color.TRANSPARENT;
+    mDisableIntervalMomentum = false;
+    mSnapInterval = 0;
+    mSnapOffsets = null;
+    mSnapToStart = true;
+    mSnapToEnd = true;
+    mSnapToAlignment = SNAP_ALIGNMENT_DISABLED;
+    mContentView = null;
+    mCurrentContentOffset = null;
+    mPendingContentOffsetX = UNSET_CONTENT_OFFSET;
+    mPendingContentOffsetY = UNSET_CONTENT_OFFSET;
+    mStateWrapper = null;
+    mReactScrollViewScrollState = new ReactScrollViewScrollState();
+    mPointerEvents = PointerEvents.AUTO;
+    mLastScrollDispatchTime = 0;
+    mScrollEventThrottle = 0;
+    mMaintainVisibleContentPositionHelper = null;
+    mFadingEdgeLengthStart = 0;
+    mFadingEdgeLengthEnd = 0;
+  }
+
+  /* package */ void recycleView() {
+    // Set default field values
+    initView();
+
+    // If the view is still attached to a parent, we need to remove it from the parent
+    // before we can recycle it.
+    if (getParent() != null) {
+      ((ViewGroup) getParent()).removeView(this);
+    }
+    updateView();
+  }
+
+  private void updateView() {}
+
   @Override
   public VirtualViewContainerState getVirtualViewContainerState() {
     if (mVirtualViewContainerState == null) {
@@ -368,9 +422,9 @@ public class ReactScrollView extends ScrollView
       // If a "pending" content offset value has been set, we restore that value.
       // Upon call to scrollTo, the "pending" values will be re-set.
       int scrollToX =
-          pendingContentOffsetX != UNSET_CONTENT_OFFSET ? pendingContentOffsetX : getScrollX();
+          mPendingContentOffsetX != UNSET_CONTENT_OFFSET ? mPendingContentOffsetX : getScrollX();
       int scrollToY =
-          pendingContentOffsetY != UNSET_CONTENT_OFFSET ? pendingContentOffsetY : getScrollY();
+          mPendingContentOffsetY != UNSET_CONTENT_OFFSET ? mPendingContentOffsetY : getScrollY();
       scrollTo(scrollToX, scrollToY);
     }
 
@@ -1269,11 +1323,11 @@ public class ReactScrollView extends ScrollView
    */
   private void setPendingContentOffsets(int x, int y) {
     if (isContentReady()) {
-      pendingContentOffsetX = UNSET_CONTENT_OFFSET;
-      pendingContentOffsetY = UNSET_CONTENT_OFFSET;
+      mPendingContentOffsetX = UNSET_CONTENT_OFFSET;
+      mPendingContentOffsetY = UNSET_CONTENT_OFFSET;
     } else {
-      pendingContentOffsetX = x;
-      pendingContentOffsetY = y;
+      mPendingContentOffsetX = x;
+      mPendingContentOffsetY = y;
     }
   }
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollViewManager.kt

@@ -15,6 +15,7 @@ import com.facebook.react.bridge.ReadableArray
 import com.facebook.react.bridge.ReadableMap
 import com.facebook.react.bridge.ReadableType
 import com.facebook.react.bridge.RetryableMountingLayerException
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
 import com.facebook.react.module.annotations.ReactModule
 import com.facebook.react.uimanager.BackgroundStyleApplicator.setBorderColor
 import com.facebook.react.uimanager.BackgroundStyleApplicator.setBorderRadius
@@ -56,6 +57,24 @@ public open class ReactScrollViewManager
 constructor(private val fpsListener: FpsListener? = null) :
     ViewGroupManager<ReactScrollView>(), ScrollCommandHandler<ReactScrollView> {
 
+  init {
+    if (ReactNativeFeatureFlags.enableViewRecyclingForScrollView()) {
+      setupViewRecycling()
+    }
+  }
+
+  override fun prepareToRecycleView(
+      reactContext: ThemedReactContext,
+      view: ReactScrollView,
+  ): ReactScrollView? {
+    // BaseViewManager
+    val preparedView = super.prepareToRecycleView(reactContext, view)
+    if (preparedView != null) {
+      preparedView.recycleView()
+    }
+    return preparedView
+  }
+
   override fun getName(): String = REACT_CLASS
 
   public override fun createViewInstance(context: ThemedReactContext): ReactScrollView =

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/virtual/view/ReactVirtualView.kt

@@ -41,6 +41,7 @@ public class ReactVirtualView(context: Context) :
   internal var modeChangeEmitter: VirtualViewModeChangeEmitter? = null
   internal var prerenderRatio: Double = ReactNativeFeatureFlags.virtualViewPrerenderRatio()
   internal val debugLogEnabled: Boolean = ReactNativeFeatureFlags.enableVirtualViewDebugFeatures()
+  private val hysteresisRatio: Double = ReactNativeFeatureFlags.virtualViewHysteresisRatio()
 
   private val onWindowFocusChangeListener =
       if (ReactNativeFeatureFlags.enableVirtualViewWindowFocusDetection()) {
@@ -188,7 +189,7 @@ public class ReactVirtualView(context: Context) :
     // If no ScrollView, or ScrollView has disabled removeClippedSubviews, use default behavior
     if (
         parentScrollView == null ||
-            !((parentScrollView as ReactClippingViewGroup)?.removeClippedSubviews ?: false)
+            !((parentScrollView as ReactClippingViewGroup).removeClippedSubviews ?: false)
     ) {
       super.updateClippingRect(excludedViews)
       return
@@ -222,6 +223,8 @@ public class ReactVirtualView(context: Context) :
         bottom + offsetY,
     )
     scrollView.getDrawingRect(thresholdRect)
+    val visibleHeight = thresholdRect.height()
+    val visibleWidth = thresholdRect.width()
 
     // TODO: Validate whether this is still the case and whether these checks are still needed.
     // updateRects will initially get called before the targetRect has any dimensions set, so if
@@ -260,16 +263,32 @@ public class ReactVirtualView(context: Context) :
       var prerender = false
       if (prerenderRatio > 0.0) {
         thresholdRect.inset(
-            (-thresholdRect.width() * prerenderRatio).toInt(),
-            (-thresholdRect.height() * prerenderRatio).toInt(),
+            (-visibleWidth * prerenderRatio).toInt(),
+            (-visibleHeight * prerenderRatio).toInt(),
         )
         prerender = rectsOverlap(targetRect, thresholdRect)
       }
       if (prerender) {
         newMode = VirtualViewMode.Prerender
       } else {
-        newMode = VirtualViewMode.Hidden
-        thresholdRect.setEmpty()
+        val _mode = mode // local variable so Kotlin knows its not nullable
+        if (_mode != null && hysteresisRatio > 0.0) {
+          thresholdRect.inset(
+              (-visibleWidth * hysteresisRatio).toInt(),
+              (-visibleHeight * hysteresisRatio).toInt(),
+          )
+          if (rectsOverlap(targetRect, thresholdRect)) {
+            // In hysteresis window, no change to mode
+            newMode = _mode
+            debugLog("dispatchOnModeChangeIfNeeded") { "hysteresis, mode=$newMode" }
+          } else {
+            newMode = VirtualViewMode.Hidden
+            thresholdRect.setEmpty()
+          }
+        } else {
+          newMode = VirtualViewMode.Hidden
+          thresholdRect.setEmpty()
+        }
       }
     }
     debugLog("dispatchOnModeChangeIfNeeded") {

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<0dadaee3f6bd74cc13295b8683e8e470>>
+ * @generated SignedSource<<16b12024bb363358ef09b9a42cb2fc97>>
  */
 
 /**
@@ -267,6 +267,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool enableViewRecyclingForScrollView() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableViewRecyclingForScrollView");
+    return method(javaProvider_);
+  }
+
   bool enableViewRecyclingForText() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableViewRecyclingForText");
@@ -435,6 +441,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  double virtualViewHysteresisRatio() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jdouble()>("virtualViewHysteresisRatio");
+    return method(javaProvider_);
+  }
+
   double virtualViewPrerenderRatio() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jdouble()>("virtualViewPrerenderRatio");
@@ -635,6 +647,11 @@ bool JReactNativeFeatureFlagsCxxInterop::enableViewRecycling(
   return ReactNativeFeatureFlags::enableViewRecycling();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::enableViewRecyclingForScrollView(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableViewRecyclingForScrollView();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::enableViewRecyclingForText(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::enableViewRecyclingForText();
@@ -775,6 +792,11 @@ bool JReactNativeFeatureFlagsCxxInterop::useTurboModules(
   return ReactNativeFeatureFlags::useTurboModules();
 }
 
+double JReactNativeFeatureFlagsCxxInterop::virtualViewHysteresisRatio(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::virtualViewHysteresisRatio();
+}
+
 double JReactNativeFeatureFlagsCxxInterop::virtualViewPrerenderRatio(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::virtualViewPrerenderRatio();
@@ -925,6 +947,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableViewRecycling",
         JReactNativeFeatureFlagsCxxInterop::enableViewRecycling),
+      makeNativeMethod(
+        "enableViewRecyclingForScrollView",
+        JReactNativeFeatureFlagsCxxInterop::enableViewRecyclingForScrollView),
       makeNativeMethod(
         "enableViewRecyclingForText",
         JReactNativeFeatureFlagsCxxInterop::enableViewRecyclingForText),
@@ -1009,6 +1034,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "useTurboModules",
         JReactNativeFeatureFlagsCxxInterop::useTurboModules),
+      makeNativeMethod(
+        "virtualViewHysteresisRatio",
+        JReactNativeFeatureFlagsCxxInterop::virtualViewHysteresisRatio),
       makeNativeMethod(
         "virtualViewPrerenderRatio",
         JReactNativeFeatureFlagsCxxInterop::virtualViewPrerenderRatio),

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<74ac256afe63253ddb6576285858444c>>
+ * @generated SignedSource<<54118ccd475a8bf1d7db83304b1f17d0>>
  */
 
 /**
@@ -144,6 +144,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableViewRecycling(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool enableViewRecyclingForScrollView(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool enableViewRecyclingForText(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
@@ -228,6 +231,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool useTurboModules(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static double virtualViewHysteresisRatio(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static double virtualViewPrerenderRatio(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

packages/react-native/ReactAndroid/src/main/jni/react/jni/CMakeLists.txt

@@ -54,7 +54,6 @@ add_library(
           CatalystInstanceImpl.cpp
           InspectorNetworkRequestListener.cpp
           JExecutor.cpp
-          JInspector.cpp
           JMessageQueueThread.cpp
           JReactCxxErrorHandler.cpp
           JReactSoftExceptionLogger.cpp

packages/react-native/ReactAndroid/src/main/jni/react/jni/JInspector.cpp

@@ -1,112 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-#include "JInspector.h"
-
-#include <memory>
-
-namespace facebook::react {
-
-namespace {
-
-class RemoteConnection : public jsinspector_modern::IRemoteConnection {
- public:
-  RemoteConnection(jni::alias_ref<JRemoteConnection::javaobject> connection)
-      : connection_(jni::make_global(connection)) {}
-
-  void onMessage(std::string message) override {
-    connection_->onMessage(message);
-  }
-
-  void onDisconnect() override {
-    connection_->onDisconnect();
-  }
-
- private:
-  jni::global_ref<JRemoteConnection::javaobject> connection_;
-};
-
-} // namespace
-
-jni::local_ref<JPage::javaobject>
-JPage::create(int id, const std::string& title, const std::string& vm) {
-  static auto constructor = javaClassStatic()
-                                ->getConstructor<JPage::javaobject(
-                                    jint,
-                                    jni::local_ref<jni::JString>,
-                                    jni::local_ref<jni::JString>)>();
-  return javaClassStatic()->newObject(
-      constructor, id, jni::make_jstring(title), jni::make_jstring(vm));
-}
-
-void JRemoteConnection::onMessage(const std::string& message) const {
-  static auto method =
-      javaClassStatic()->getMethod<void(jni::local_ref<jstring>)>("onMessage");
-  method(self(), jni::make_jstring(message));
-}
-
-void JRemoteConnection::onDisconnect() const {
-  static auto method = javaClassStatic()->getMethod<void()>("onDisconnect");
-  method(self());
-}
-
-JLocalConnection::JLocalConnection(
-    std::unique_ptr<jsinspector_modern::ILocalConnection> connection)
-    : connection_(std::move(connection)) {}
-
-void JLocalConnection::sendMessage(std::string message) {
-  connection_->sendMessage(std::move(message));
-}
-
-void JLocalConnection::disconnect() {
-  connection_->disconnect();
-}
-
-void JLocalConnection::registerNatives() {
-  javaClassStatic()->registerNatives({
-      makeNativeMethod("sendMessage", JLocalConnection::sendMessage),
-      makeNativeMethod("disconnect", JLocalConnection::disconnect),
-  });
-}
-
-jni::global_ref<JInspector::javaobject> JInspector::instance(
-    jni::alias_ref<jclass> /*unused*/) {
-  static auto instance = jni::make_global(
-      newObjectCxxArgs(&jsinspector_modern::getInspectorInstance()));
-  return instance;
-}
-
-jni::local_ref<jni::JArrayClass<JPage::javaobject>> JInspector::getPages() {
-  std::vector<jsinspector_modern::InspectorPageDescription> pages =
-      inspector_->getPages();
-  auto array = jni::JArrayClass<JPage::javaobject>::newArray(pages.size());
-  for (size_t i = 0; i < pages.size(); i++) {
-    (*array)[i] = JPage::create(pages[i].id, pages[i].description, pages[i].vm);
-  }
-  return array;
-}
-
-jni::local_ref<JLocalConnection::javaobject> JInspector::connect(
-    int pageId,
-    jni::alias_ref<JRemoteConnection::javaobject> remote) {
-  auto localConnection = inspector_->connect(
-      pageId, std::make_unique<RemoteConnection>(std::move(remote)));
-  return localConnection
-      ? JLocalConnection::newObjectCxxArgs(std::move(localConnection))
-      : nullptr;
-}
-
-void JInspector::registerNatives() {
-  JLocalConnection::registerNatives();
-  javaClassStatic()->registerNatives({
-      makeNativeMethod("instance", JInspector::instance),
-      makeNativeMethod("getPagesNative", JInspector::getPages),
-      makeNativeMethod("connectNative", JInspector::connect),
-  });
-}
-
-} // namespace facebook::react

packages/react-native/ReactAndroid/src/main/jni/react/jni/JInspector.h

@@ -1,77 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-#pragma once
-
-#include <jsinspector-modern/InspectorInterfaces.h>
-
-#include <fbjni/fbjni.h>
-
-#include <memory>
-
-namespace facebook::react {
-
-class JPage : public jni::JavaClass<JPage> {
- public:
-  static constexpr auto kJavaDescriptor =
-      "Lcom/facebook/react/bridge/Inspector$Page;";
-
-  static jni::local_ref<JPage::javaobject>
-  create(int id, const std::string& title, const std::string& vm);
-};
-
-class JRemoteConnection : public jni::JavaClass<JRemoteConnection> {
- public:
-  static constexpr auto kJavaDescriptor =
-      "Lcom/facebook/react/bridge/Inspector$RemoteConnection;";
-
-  void onMessage(const std::string& message) const;
-  void onDisconnect() const;
-};
-
-class JLocalConnection : public jni::HybridClass<JLocalConnection> {
- public:
-  static constexpr auto kJavaDescriptor =
-      "Lcom/facebook/react/bridge/Inspector$LocalConnection;";
-
-  JLocalConnection(
-      std::unique_ptr<jsinspector_modern::ILocalConnection> connection);
-
-  void sendMessage(std::string message);
-  void disconnect();
-
-  static void registerNatives();
-
- private:
-  std::unique_ptr<jsinspector_modern::ILocalConnection> connection_;
-};
-
-class JInspector : public jni::HybridClass<JInspector> {
- public:
-  static constexpr auto kJavaDescriptor =
-      "Lcom/facebook/react/bridge/Inspector;";
-
-  static jni::global_ref<JInspector::javaobject> instance(
-      jni::alias_ref<jclass>);
-
-  jni::local_ref<jni::JArrayClass<JPage::javaobject>> getPages();
-  jni::local_ref<JLocalConnection::javaobject> connect(
-      int pageId,
-      jni::alias_ref<JRemoteConnection::javaobject> remote);
-
-  static void registerNatives();
-
- private:
-  friend HybridBase;
-
-  JInspector(jsinspector_modern::IInspector* inspector)
-      : inspector_(inspector) {}
-
-  jsinspector_modern::IInspector* inspector_;
-};
-
-} // namespace facebook::react

packages/react-native/ReactAndroid/src/main/jni/react/jni/OnLoad.cpp

@@ -13,7 +13,6 @@
 #include "CatalystInstanceImpl.h"
 #include "CxxModuleWrapperBase.h"
 #include "InspectorNetworkRequestListener.h"
-#include "JInspector.h"
 #include "JavaScriptExecutorHolder.h"
 #include "ReactInstanceManagerInspectorTarget.h"
 
@@ -41,7 +40,6 @@ extern "C" JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
     CatalystInstanceImpl::registerNatives();
 #endif
     CxxModuleWrapperBase::registerNatives();
-    JInspector::registerNatives();
     ReactInstanceManagerInspectorTarget::registerNatives();
     InspectorNetworkRequestListener::registerNatives();
   });

packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactHostInspectorTarget.cpp

@@ -80,15 +80,6 @@ void JReactHostInspectorTarget::sendDebuggerResumeCommand() {
   }
 }
 
-void JReactHostInspectorTarget::registerNatives() {
-  registerHybrid({
-      makeNativeMethod("initHybrid", JReactHostInspectorTarget::initHybrid),
-      makeNativeMethod(
-          "sendDebuggerResumeCommand",
-          JReactHostInspectorTarget::sendDebuggerResumeCommand),
-  });
-}
-
 jsinspector_modern::HostTargetMetadata
 JReactHostInspectorTarget::getMetadata() {
   jsinspector_modern::HostTargetMetadata metadata = {
@@ -157,4 +148,63 @@ HostTarget* JReactHostInspectorTarget::getInspectorTarget() {
   return inspectorTarget_ ? inspectorTarget_.get() : nullptr;
 }
 
+bool JReactHostInspectorTarget::startBackgroundTrace() {
+  if (inspectorTarget_) {
+    return inspectorTarget_->startTracing(tracing::Mode::Background);
+  } else {
+    jni::throwNewJavaException(
+        "java/lang/IllegalStateException",
+        "Cannot start Tracing session while the Fusebox backend is not enabled.");
+  }
+}
+
+tracing::TraceRecordingState JReactHostInspectorTarget::stopTracing() {
+  if (inspectorTarget_) {
+    return inspectorTarget_->stopTracing();
+  } else {
+    jni::throwNewJavaException(
+        "java/lang/IllegalStateException",
+        "Cannot stop Tracing session while the Fusebox backend is not enabled.");
+  }
+}
+
+void JReactHostInspectorTarget::stopAndStashBackgroundTrace() {
+  auto capturedTrace = inspectorTarget_->stopTracing();
+  stashTraceRecordingState(std::move(capturedTrace));
+}
+
+void JReactHostInspectorTarget::stopAndDiscardBackgroundTrace() {
+  inspectorTarget_->stopTracing();
+}
+
+void JReactHostInspectorTarget::stashTraceRecordingState(
+    tracing::TraceRecordingState&& state) {
+  stashedTraceRecordingState_ = std::move(state);
+}
+
+std::optional<tracing::TraceRecordingState> JReactHostInspectorTarget::
+    unstable_getTraceRecordingThatWillBeEmittedOnInitialization() {
+  auto state = std::move(stashedTraceRecordingState_);
+  stashedTraceRecordingState_.reset();
+  return state;
+}
+
+void JReactHostInspectorTarget::registerNatives() {
+  registerHybrid({
+      makeNativeMethod("initHybrid", JReactHostInspectorTarget::initHybrid),
+      makeNativeMethod(
+          "sendDebuggerResumeCommand",
+          JReactHostInspectorTarget::sendDebuggerResumeCommand),
+      makeNativeMethod(
+          "startBackgroundTrace",
+          JReactHostInspectorTarget::startBackgroundTrace),
+      makeNativeMethod(
+          "stopAndStashBackgroundTrace",
+          JReactHostInspectorTarget::stopAndStashBackgroundTrace),
+      makeNativeMethod(
+          "stopAndDiscardBackgroundTrace",
+          JReactHostInspectorTarget::stopAndDiscardBackgroundTrace),
+  });
+}
+
 } // namespace facebook::react

packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactHostInspectorTarget.h

@@ -77,6 +77,22 @@ class JReactHostInspectorTarget
   static void registerNatives();
   void sendDebuggerResumeCommand();
 
+  /**
+   * Starts a background trace recording for this HostTarget.
+   *
+   * \return false if already tracing, true otherwise.
+   */
+  bool startBackgroundTrace();
+  /**
+   * Stops previously started trace recording and stashes the captured trace,
+   * which will be emitted the next time CDP session is created.
+   */
+  void stopAndStashBackgroundTrace();
+  /**
+   * Stops previously started trace recording and discards the captured trace.
+   */
+  void stopAndDiscardBackgroundTrace();
+
   jsinspector_modern::HostTarget* getInspectorTarget();
 
   // HostTargetDelegate methods
@@ -90,6 +106,8 @@ class JReactHostInspectorTarget
       const jsinspector_modern::LoadNetworkResourceRequest& params,
       jsinspector_modern::ScopedExecutor<
           jsinspector_modern::NetworkRequestListener> executor) override;
+  std::optional<jsinspector_modern::tracing::TraceRecordingState>
+  unstable_getTraceRecordingThatWillBeEmittedOnInitialization() override;
 
  private:
   JReactHostInspectorTarget(
@@ -106,6 +124,24 @@ class JReactHostInspectorTarget
   std::shared_ptr<jsinspector_modern::HostTarget> inspectorTarget_;
   std::optional<int> inspectorPageId_;
 
+  /**
+   * Stops previously started trace recording and returns the captured trace.
+   */
+  jsinspector_modern::tracing::TraceRecordingState stopTracing();
+  /**
+   * Stashes previously recorded trace recording state that will be emitted when
+   * CDP session is created. Once emitted, the value will be cleared from this
+   * instance.
+   */
+  void stashTraceRecordingState(
+      jsinspector_modern::tracing::TraceRecordingState&& state);
+  /**
+   * Previously recorded trace recording state that will be emitted when
+   * CDP session is created.
+   */
+  std::optional<jsinspector_modern::tracing::TraceRecordingState>
+      stashedTraceRecordingState_;
+
   friend HybridBase;
 };
 } // namespace facebook::react

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/bridge/BaseJavaModuleTest.kt

@@ -44,7 +44,7 @@ class BaseJavaModuleTest {
   private fun findMethod(mname: String, methods: List<JavaModuleWrapper.MethodDescriptor>): Int =
       methods.indexOfFirst({ it.name === mname })
 
-  @Test(expected = NativeArgumentsParseException::class)
+  @Test(expected = JSApplicationCausedNativeException::class)
   fun testCallMethodWithoutEnoughArgs() {
     val methodId = findMethod("regularMethod", methods)
     whenever(arguments.size()).thenReturn(1)

packages/react-native/ReactCommon/jsi/jsi/decorator.h

@@ -328,6 +328,18 @@ class RuntimeDecorator : public Base, private jsi::Instrumentation {
     plain_.setPropertyValue(o, name, value);
   };
 
+  void deleteProperty(const Object& object, const PropNameID& name) override {
+    plain_.deleteProperty(object, name);
+  }
+
+  void deleteProperty(const Object& object, const String& name) override {
+    plain_.deleteProperty(object, name);
+  }
+
+  void deleteProperty(const Object& object, const Value& name) override {
+    plain_.deleteProperty(object, name);
+  }
+
   bool isArray(const Object& o) const override {
     return plain_.isArray(o);
   };
@@ -852,6 +864,21 @@ class WithRuntimeDecorator : public RuntimeDecorator<Plain, Base> {
     RD::setPropertyValue(o, name, value);
   };
 
+  void deleteProperty(const Object& object, const PropNameID& name) override {
+    Around around{with_};
+    RD::deleteProperty(object, name);
+  }
+
+  void deleteProperty(const Object& object, const String& name) override {
+    Around around{with_};
+    RD::deleteProperty(object, name);
+  }
+
+  void deleteProperty(const Object& object, const Value& name) override {
+    Around around{with_};
+    RD::deleteProperty(object, name);
+  }
+
   bool isArray(const Object& o) const override {
     Around around{with_};
     return RD::isArray(o);

packages/react-native/ReactCommon/jsi/jsi/jsi-inl.h

@@ -148,6 +148,23 @@ void Object::setProperty(Runtime& runtime, const PropNameID& name, T&& value)
       runtime, name, detail::toValue(runtime, std::forward<T>(value)));
 }
 
+inline void Object::deleteProperty(Runtime& runtime, const char* name) const {
+  deleteProperty(runtime, String::createFromAscii(runtime, name));
+}
+
+inline void Object::deleteProperty(Runtime& runtime, const String& name) const {
+  runtime.deleteProperty(*this, name);
+}
+
+inline void Object::deleteProperty(Runtime& runtime, const PropNameID& name)
+    const {
+  runtime.deleteProperty(*this, name);
+}
+
+inline void Object::deleteProperty(Runtime& runtime, const Value& name) const {
+  runtime.deleteProperty(*this, name);
+}
+
 inline Array Object::getArray(Runtime& runtime) const& {
   assert(runtime.isArray(*this));
   (void)runtime; // when assert is disabled we need to mark this as used

packages/react-native/ReactCommon/jsi/jsi/jsi.cpp

@@ -416,6 +416,37 @@ Object Runtime::createObjectWithPrototype(const Value& prototype) {
   return createFn.call(*this, prototype).asObject(*this);
 }
 
+void Runtime::deleteProperty(const Object& object, const PropNameID& name) {
+  auto nameStr = String::createFromUtf16(*this, name.utf16(*this));
+  auto deleteFn = global()
+                      .getPropertyAsObject(*this, "Reflect")
+                      .getPropertyAsFunction(*this, "deleteProperty");
+  auto res = deleteFn.call(*this, object, nameStr).getBool();
+  if (!res) {
+    throw JSError(*this, "Failed to delete property");
+  }
+}
+
+void Runtime::deleteProperty(const Object& object, const String& name) {
+  auto deleteFn = global()
+                      .getPropertyAsObject(*this, "Reflect")
+                      .getPropertyAsFunction(*this, "deleteProperty");
+  auto res = deleteFn.call(*this, object, name).getBool();
+  if (!res) {
+    throw JSError(*this, "Failed to delete property");
+  }
+}
+
+void Runtime::deleteProperty(const Object& object, const Value& name) {
+  auto deleteFn = global()
+                      .getPropertyAsObject(*this, "Reflect")
+                      .getPropertyAsFunction(*this, "deleteProperty");
+  auto res = deleteFn.call(*this, object, name).getBool();
+  if (!res) {
+    throw JSError(*this, "Failed to delete property");
+  }
+}
+
 void Runtime::setRuntimeDataImpl(
     const UUID& uuid,
     const void* data,

packages/react-native/ReactCommon/jsi/jsi/jsi.h

@@ -486,6 +486,10 @@ class JSI_EXPORT Runtime : public ICast {
   virtual void
   setPropertyValue(const Object&, const String& name, const Value& value) = 0;
 
+  virtual void deleteProperty(const Object&, const PropNameID& name);
+  virtual void deleteProperty(const Object&, const String& name);
+  virtual void deleteProperty(const Object&, const Value& name);
+
   virtual bool isArray(const Object&) const = 0;
   virtual bool isArrayBuffer(const Object&) const = 0;
   virtual bool isFunction(const Object&) const = 0;
@@ -984,6 +988,22 @@ class JSI_EXPORT Object : public Pointer {
   template <typename T>
   void setProperty(Runtime& runtime, const PropNameID& name, T&& value) const;
 
+  /// Delete the property with the given ascii name. Throws if the deletion
+  /// failed.
+  void deleteProperty(Runtime& runtime, const char* name) const;
+
+  /// Delete the property with the given String name. Throws if the deletion
+  /// failed.
+  void deleteProperty(Runtime& runtime, const String& name) const;
+
+  /// Delete the property with the given PropNameID name. Throws if the deletion
+  /// failed.
+  void deleteProperty(Runtime& runtime, const PropNameID& name) const;
+
+  /// Delete the property with the given Value name. Throws if the deletion
+  /// failed.
+  void deleteProperty(Runtime& runtime, const Value& name) const;
+
   /// \return true iff JS \c Array.isArray() would return \c true.  If
   /// so, then \c getArray() will succeed.
   bool isArray(Runtime& runtime) const {

packages/react-native/ReactCommon/jsi/jsi/test/testlib.cpp

@@ -1882,6 +1882,65 @@ TEST_P(JSITest, CastInterface) {
   EXPECT_TRUE(ptr == nullptr);
 }
 
+TEST_P(JSITest, DeleteProperty) {
+  // This Runtime Decorator is used to test the default implementation of
+  // Runtime::deleteProperty
+  class RD : public RuntimeDecorator<Runtime, Runtime> {
+   public:
+    explicit RD(Runtime& rt) : RuntimeDecorator(rt) {}
+
+    void deleteProperty(const Object& object, const PropNameID& name) override {
+      Runtime::deleteProperty(object, name);
+    }
+    void deleteProperty(const Object& object, const String& name) override {
+      Runtime::deleteProperty(object, name);
+    }
+    void deleteProperty(const Object& object, const Value& name) override {
+      Runtime::deleteProperty(object, name);
+    }
+  };
+  RD rd = RD(rt);
+  auto obj = eval("obj = {1:2, foo: 'bar', 3: 4, salt:'pepper'}").getObject(rd);
+
+  auto prop = PropNameID::forAscii(rd, "1");
+  auto hasRes = obj.hasProperty(rd, prop);
+  EXPECT_TRUE(hasRes);
+  obj.deleteProperty(rd, prop);
+  hasRes = obj.hasProperty(rd, prop);
+  EXPECT_FALSE(hasRes);
+
+  auto str = String::createFromAscii(rd, "foo");
+  hasRes = obj.hasProperty(rd, str);
+  EXPECT_TRUE(hasRes);
+  obj.deleteProperty(rd, str);
+  hasRes = obj.hasProperty(rd, str);
+  EXPECT_FALSE(hasRes);
+
+  auto valProp = Value(3);
+  hasRes = obj.hasProperty(rd, "3");
+  EXPECT_TRUE(hasRes);
+  obj.deleteProperty(rd, valProp);
+  auto getRes = obj.getProperty(rd, "3");
+  EXPECT_TRUE(getRes.isUndefined());
+
+  hasRes = obj.hasProperty(rd, "salt");
+  EXPECT_TRUE(hasRes);
+  obj.deleteProperty(rd, "salt");
+  hasRes = obj.hasProperty(rd, "salt");
+  EXPECT_FALSE(hasRes);
+
+  obj = eval(
+            "const obj = {};"
+            "Object.defineProperty(obj, 'prop', {"
+            "  value: 10,"
+            "  configurable: false,});"
+            "obj;")
+            .getObject(rd);
+  EXPECT_THROW(obj.deleteProperty(rd, "prop"), JSError);
+  hasRes = obj.hasProperty(rd, "prop");
+  EXPECT_TRUE(hasRes);
+}
+
 INSTANTIATE_TEST_CASE_P(
     Runtimes,
     JSITest,

packages/react-native/ReactCommon/jsinspector-modern/HostAgent.cpp

@@ -41,14 +41,18 @@ class HostAgent::Impl final {
       HostTargetController& targetController,
       HostTargetMetadata hostMetadata,
       SessionState& sessionState,
-      VoidExecutor executor)
+      VoidExecutor executor,
+      std::optional<tracing::TraceRecordingState> traceRecordingToEmit)
       : frontendChannel_(frontendChannel),
         targetController_(targetController),
         hostMetadata_(std::move(hostMetadata)),
         sessionState_(sessionState),
         networkIOAgent_(NetworkIOAgent(frontendChannel, std::move(executor))),
-        tracingAgent_(
-            TracingAgent(frontendChannel, sessionState, targetController)) {}
+        tracingAgent_(TracingAgent(
+            frontendChannel,
+            sessionState,
+            targetController,
+            std::move(traceRecordingToEmit))) {}
 
   ~Impl() {
     if (isPausedInDebuggerOverlayVisible_) {
@@ -428,7 +432,8 @@ class HostAgent::Impl final {
       HostTargetController& targetController,
       HostTargetMetadata hostMetadata,
       SessionState& sessionState,
-      VoidExecutor executor) {}
+      VoidExecutor executor,
+      std::optional<tracing::TraceRecordingState> traceRecordingToEmit) {}
 
   void handleRequest(const cdp::PreparsedRequest& req) {}
   void setCurrentInstanceAgent(std::shared_ptr<InstanceAgent> agent) {}
@@ -441,14 +446,16 @@ HostAgent::HostAgent(
     HostTargetController& targetController,
     HostTargetMetadata hostMetadata,
     SessionState& sessionState,
-    VoidExecutor executor)
+    VoidExecutor executor,
+    std::optional<tracing::TraceRecordingState> traceRecordingToEmit)
     : impl_(std::make_unique<Impl>(
           *this,
           frontendChannel,
           targetController,
           std::move(hostMetadata),
           sessionState,
-          std::move(executor))) {}
+          std::move(executor),
+          std::move(traceRecordingToEmit))) {}
 
 HostAgent::~HostAgent() = default;
 

packages/react-native/ReactCommon/jsinspector-modern/HostAgent.h

@@ -36,13 +36,16 @@ class HostAgent final {
    * \param hostMetadata Metadata about the host that created this agent.
    * \param sessionState The state of the session that created this agent.
    * \param executor A void executor to be used by async-aware handlers.
+   * \param traceRecordingToEmit If set, this is the trace that Host has
+   * requested to display in the Frontend.
    */
   HostAgent(
       const FrontendChannel& frontendChannel,
       HostTargetController& targetController,
       HostTargetMetadata hostMetadata,
       SessionState& sessionState,
-      VoidExecutor executor);
+      VoidExecutor executor,
+      std::optional<tracing::TraceRecordingState> traceRecordingToEmit);
 
   HostAgent(const HostAgent&) = delete;
   HostAgent(HostAgent&&) = delete;

packages/react-native/ReactCommon/jsinspector-modern/HostTarget.cpp

@@ -34,7 +34,8 @@ class HostTargetSession {
       std::unique_ptr<IRemoteConnection> remote,
       HostTargetController& targetController,
       HostTargetMetadata hostMetadata,
-      VoidExecutor executor)
+      VoidExecutor executor,
+      std::optional<tracing::TraceRecordingState> traceRecordingToEmit)
       : remote_(std::make_shared<RAIIRemoteConnection>(std::move(remote))),
         frontendChannel_(
             [remoteWeak = std::weak_ptr(remote_)](std::string_view message) {
@@ -47,7 +48,8 @@ class HostTargetSession {
             targetController,
             std::move(hostMetadata),
             state_,
-            std::move(executor)) {}
+            std::move(executor),
+            std::move(traceRecordingToEmit)) {}
 
   /**
    * Called by CallbackLocalConnection to send a message to this Session's
@@ -206,7 +208,8 @@ std::unique_ptr<ILocalConnection> HostTarget::connect(
       std::move(connectionToFrontend),
       controller_,
       delegate_.getMetadata(),
-      makeVoidExecutor(executorFromThis()));
+      makeVoidExecutor(executorFromThis()),
+      delegate_.unstable_getTraceRecordingThatWillBeEmittedOnInitialization());
   session->setCurrentInstance(currentInstance_.get());
   sessions_.insert(std::weak_ptr(session));
   return std::make_unique<CallbackLocalConnection>(
@@ -217,6 +220,11 @@ HostTarget::~HostTarget() {
   // HostCommandSender owns a session, so we must release it for the assertion
   // below to be valid.
   commandSender_.reset();
+
+  // HostRuntimeBinding owns a connection, so we must release it for the
+  // assertion
+  perfMetricsBinding_.reset();
+
   // Sessions are owned by InspectorPackagerConnection, not by HostTarget, but
   // they hold a HostTarget& that we must guarantee is valid.
   assert(

packages/react-native/ReactCommon/jsinspector-modern/HostTarget.h

@@ -146,6 +146,19 @@ class HostTargetDelegate : public LoadNetworkResourceDelegate {
     throw NotImplementedException(
         "LoadNetworkResourceDelegate.loadNetworkResource is not implemented by this host target delegate.");
   }
+
+  /**
+   * [Experimental] Will be called at the CDP session initialization to get the
+   * trace recording that may have been stashed by the Host from the previous
+   * background session.
+   *
+   * \return the trace recording state if there is one that needs to be
+   * displayed, otherwise std::nullopt.
+   */
+  virtual std::optional<tracing::TraceRecordingState>
+  unstable_getTraceRecordingThatWillBeEmittedOnInitialization() {
+    return std::nullopt;
+  }
 };
 
 /**

packages/react-native/ReactCommon/jsinspector-modern/TracingAgent.cpp

@@ -38,10 +38,17 @@ const uint16_t PROFILE_TRACE_EVENT_CHUNK_SIZE = 1;
 TracingAgent::TracingAgent(
     FrontendChannel frontendChannel,
     SessionState& sessionState,
-    HostTargetController& hostTargetController)
+    HostTargetController& hostTargetController,
+    std::optional<tracing::TraceRecordingState> traceRecordingToEmit)
     : frontendChannel_(std::move(frontendChannel)),
       sessionState_(sessionState),
-      hostTargetController_(hostTargetController) {}
+      hostTargetController_(hostTargetController) {
+  if (traceRecordingToEmit.has_value()) {
+    frontendChannel_(
+        cdp::jsonNotification("ReactNativeApplication.traceRequested"));
+    emitTraceRecording(std::move(traceRecordingToEmit.value()));
+  }
+}
 
 TracingAgent::~TracingAgent() {
   // Agents are owned by the session. If the agent is destroyed, it means that
@@ -86,25 +93,29 @@ bool TracingAgent::handleRequest(const cdp::PreparsedRequest& req) {
     // Send response to Tracing.end request.
     frontendChannel_(cdp::jsonResult(req.id));
 
-    auto dataCollectedCallback = [this](folly::dynamic&& eventsChunk) {
-      frontendChannel_(cdp::jsonNotification(
-          "Tracing.dataCollected",
-          folly::dynamic::object("value", std::move(eventsChunk))));
-    };
-    tracing::TraceRecordingStateSerializer::emitAsDataCollectedChunks(
-        std::move(state),
-        dataCollectedCallback,
-        TRACE_EVENT_CHUNK_SIZE,
-        PROFILE_TRACE_EVENT_CHUNK_SIZE);
-
-    frontendChannel_(cdp::jsonNotification(
-        "Tracing.tracingComplete",
-        folly::dynamic::object("dataLossOccurred", false)));
-
+    emitTraceRecording(std::move(state));
     return true;
   }
 
   return false;
 }
 
+void TracingAgent::emitTraceRecording(
+    tracing::TraceRecordingState state) const {
+  auto dataCollectedCallback = [this](folly::dynamic&& eventsChunk) {
+    frontendChannel_(cdp::jsonNotification(
+        "Tracing.dataCollected",
+        folly::dynamic::object("value", std::move(eventsChunk))));
+  };
+  tracing::TraceRecordingStateSerializer::emitAsDataCollectedChunks(
+      std::move(state),
+      dataCollectedCallback,
+      TRACE_EVENT_CHUNK_SIZE,
+      PROFILE_TRACE_EVENT_CHUNK_SIZE);
+
+  frontendChannel_(cdp::jsonNotification(
+      "Tracing.tracingComplete",
+      folly::dynamic::object("dataLossOccurred", false)));
+}
+
 } // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/TracingAgent.h

@@ -24,11 +24,18 @@ class TracingAgent {
   /**
    * \param frontendChannel A channel used to send responses to the
    * frontend.
+   * \param sessionState The state of the session that created this agent.
+   * \param hostTargetController An interface to the HostTarget that this agent
+   * is attached to. The caller is responsible for ensuring that the
+   * HostTargetDelegate and underlying HostTarget both outlive the agent.
+   * \param traceRecordingToEmit If set, this is the trace that Host has
+   * requested to display in the Frontend.
    */
   TracingAgent(
       FrontendChannel frontendChannel,
       SessionState& sessionState,
-      HostTargetController& hostTargetController);
+      HostTargetController& hostTargetController,
+      std::optional<tracing::TraceRecordingState> traceRecordingToEmit);
 
   ~TracingAgent();
 
@@ -48,6 +55,12 @@ class TracingAgent {
   SessionState& sessionState_;
 
   HostTargetController& hostTargetController_;
+
+  /**
+   * Emits the captured Trace Recording state in a series of
+   * Tracing.dataCollected events, followed by a Tracing.tracingComplete event.
+   */
+  void emitTraceRecording(tracing::TraceRecordingState state) const;
 };
 
 } // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracer.cpp

@@ -190,6 +190,7 @@ void PerformanceTracer::reportTimeStamp(
       .trackName = std::move(trackName),
       .trackGroup = std::move(trackGroup),
       .color = std::move(color),
+      .threadId = getCurrentThreadId(),
   });
 }
 
@@ -399,7 +400,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'X',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .dur = event.end - event.start,
             });
           },
@@ -410,7 +411,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'X',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .dur = event.end - event.start,
             });
           },
@@ -429,7 +430,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'I',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .args = std::move(eventArgs),
             });
           },
@@ -449,7 +450,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'b',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .args = std::move(beginEventArgs),
             });
             events.emplace_back(TraceEvent{
@@ -459,7 +460,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'e',
                 .ts = event.start + event.duration,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
             });
           },
           [&](PerformanceTracerEventTimeStamp&& event) {
@@ -500,7 +501,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'I',
                 .ts = event.createdAt,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .args = folly::dynamic::object("data", std::move(data)),
             });
           },

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<392fdd6e857b7c8ae99329b927be6ae0>>
+ * @generated SignedSource<<12a06ea04fc09c34f1fbdcbdf6046d81>>
  */
 
 /**
@@ -178,6 +178,10 @@ bool ReactNativeFeatureFlags::enableViewRecycling() {
   return getAccessor().enableViewRecycling();
 }
 
+bool ReactNativeFeatureFlags::enableViewRecyclingForScrollView() {
+  return getAccessor().enableViewRecyclingForScrollView();
+}
+
 bool ReactNativeFeatureFlags::enableViewRecyclingForText() {
   return getAccessor().enableViewRecyclingForText();
 }
@@ -290,6 +294,10 @@ bool ReactNativeFeatureFlags::useTurboModules() {
   return getAccessor().useTurboModules();
 }
 
+double ReactNativeFeatureFlags::virtualViewHysteresisRatio() {
+  return getAccessor().virtualViewHysteresisRatio();
+}
+
 double ReactNativeFeatureFlags::virtualViewPrerenderRatio() {
   return getAccessor().virtualViewPrerenderRatio();
 }

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<b601a3c92cd80549ca2391ab0a123214>>
+ * @generated SignedSource<<eee81e4e9bb13ef5134d4e2d79876b38>>
  */
 
 /**
@@ -229,6 +229,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableViewRecycling();
 
+  /**
+   * Enables View Recycling for <ScrollView> via ReactViewGroup/ReactViewManager.
+   */
+  RN_EXPORT static bool enableViewRecyclingForScrollView();
+
   /**
    * Enables View Recycling for <Text> via ReactTextView/ReactTextViewManager.
    */
@@ -369,6 +374,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool useTurboModules();
 
+  /**
+   * Sets a hysteresis window for transition between prerender and hidden modes.
+   */
+  RN_EXPORT static double virtualViewHysteresisRatio();
+
   /**
    * Initial prerender ratio for VirtualView.
    */

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<69518331e8b6225d4aa524e46951302d>>
+ * @generated SignedSource<<3c5588a851e6cdefaba22236c5ebb828>>
  */
 
 /**
@@ -713,6 +713,24 @@ bool ReactNativeFeatureFlagsAccessor::enableViewRecycling() {
   return flagValue.value();
 }
 
+bool ReactNativeFeatureFlagsAccessor::enableViewRecyclingForScrollView() {
+  auto flagValue = enableViewRecyclingForScrollView_.load();
+
+  if (!flagValue.has_value()) {
+    // This block is not exclusive but it is not necessary.
+    // If multiple threads try to initialize the feature flag, we would only
+    // be accessing the provider multiple times but the end state of this
+    // instance and the returned flag value would be the same.
+
+    markFlagAsAccessed(38, "enableViewRecyclingForScrollView");
+
+    flagValue = currentProvider_->enableViewRecyclingForScrollView();
+    enableViewRecyclingForScrollView_ = flagValue;
+  }
+
+  return flagValue.value();
+}
+
 bool ReactNativeFeatureFlagsAccessor::enableViewRecyclingForText() {
   auto flagValue = enableViewRecyclingForText_.load();
 
@@ -722,7 +740,7 @@ bool ReactNativeFeatureFlagsAccessor::enableViewRecyclingForText() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(38, "enableViewRecyclingForText");
+    markFlagAsAccessed(39, "enableViewRecyclingForText");
 
     flagValue = currentProvider_->enableViewRecyclingForText();
     enableViewRecyclingForText_ = flagValue;
@@ -740,7 +758,7 @@ bool ReactNativeFeatureFlagsAccessor::enableViewRecyclingForView() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(39, "enableViewRecyclingForView");
+    markFlagAsAccessed(40, "enableViewRecyclingForView");
 
     flagValue = currentProvider_->enableViewRecyclingForView();
     enableViewRecyclingForView_ = flagValue;
@@ -758,7 +776,7 @@ bool ReactNativeFeatureFlagsAccessor::enableVirtualViewDebugFeatures() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(40, "enableVirtualViewDebugFeatures");
+    markFlagAsAccessed(41, "enableVirtualViewDebugFeatures");
 
     flagValue = currentProvider_->enableVirtualViewDebugFeatures();
     enableVirtualViewDebugFeatures_ = flagValue;
@@ -776,7 +794,7 @@ bool ReactNativeFeatureFlagsAccessor::enableVirtualViewRenderState() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(41, "enableVirtualViewRenderState");
+    markFlagAsAccessed(42, "enableVirtualViewRenderState");
 
     flagValue = currentProvider_->enableVirtualViewRenderState();
     enableVirtualViewRenderState_ = flagValue;
@@ -794,7 +812,7 @@ bool ReactNativeFeatureFlagsAccessor::enableVirtualViewWindowFocusDetection() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(42, "enableVirtualViewWindowFocusDetection");
+    markFlagAsAccessed(43, "enableVirtualViewWindowFocusDetection");
 
     flagValue = currentProvider_->enableVirtualViewWindowFocusDetection();
     enableVirtualViewWindowFocusDetection_ = flagValue;
@@ -812,7 +830,7 @@ bool ReactNativeFeatureFlagsAccessor::fixMappingOfEventPrioritiesBetweenFabricAn
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(43, "fixMappingOfEventPrioritiesBetweenFabricAndReact");
+    markFlagAsAccessed(44, "fixMappingOfEventPrioritiesBetweenFabricAndReact");
 
     flagValue = currentProvider_->fixMappingOfEventPrioritiesBetweenFabricAndReact();
     fixMappingOfEventPrioritiesBetweenFabricAndReact_ = flagValue;
@@ -830,7 +848,7 @@ bool ReactNativeFeatureFlagsAccessor::fuseboxEnabledRelease() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(44, "fuseboxEnabledRelease");
+    markFlagAsAccessed(45, "fuseboxEnabledRelease");
 
     flagValue = currentProvider_->fuseboxEnabledRelease();
     fuseboxEnabledRelease_ = flagValue;
@@ -848,7 +866,7 @@ bool ReactNativeFeatureFlagsAccessor::fuseboxNetworkInspectionEnabled() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(45, "fuseboxNetworkInspectionEnabled");
+    markFlagAsAccessed(46, "fuseboxNetworkInspectionEnabled");
 
     flagValue = currentProvider_->fuseboxNetworkInspectionEnabled();
     fuseboxNetworkInspectionEnabled_ = flagValue;
@@ -866,7 +884,7 @@ bool ReactNativeFeatureFlagsAccessor::hideOffscreenVirtualViewsOnIOS() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(46, "hideOffscreenVirtualViewsOnIOS");
+    markFlagAsAccessed(47, "hideOffscreenVirtualViewsOnIOS");
 
     flagValue = currentProvider_->hideOffscreenVirtualViewsOnIOS();
     hideOffscreenVirtualViewsOnIOS_ = flagValue;
@@ -884,7 +902,7 @@ bool ReactNativeFeatureFlagsAccessor::perfMonitorV2Enabled() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(47, "perfMonitorV2Enabled");
+    markFlagAsAccessed(48, "perfMonitorV2Enabled");
 
     flagValue = currentProvider_->perfMonitorV2Enabled();
     perfMonitorV2Enabled_ = flagValue;
@@ -902,7 +920,7 @@ double ReactNativeFeatureFlagsAccessor::preparedTextCacheSize() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(48, "preparedTextCacheSize");
+    markFlagAsAccessed(49, "preparedTextCacheSize");
 
     flagValue = currentProvider_->preparedTextCacheSize();
     preparedTextCacheSize_ = flagValue;
@@ -920,7 +938,7 @@ bool ReactNativeFeatureFlagsAccessor::preventShadowTreeCommitExhaustion() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(49, "preventShadowTreeCommitExhaustion");
+    markFlagAsAccessed(50, "preventShadowTreeCommitExhaustion");
 
     flagValue = currentProvider_->preventShadowTreeCommitExhaustion();
     preventShadowTreeCommitExhaustion_ = flagValue;
@@ -938,7 +956,7 @@ bool ReactNativeFeatureFlagsAccessor::releaseImageDataWhenConsumed() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(50, "releaseImageDataWhenConsumed");
+    markFlagAsAccessed(51, "releaseImageDataWhenConsumed");
 
     flagValue = currentProvider_->releaseImageDataWhenConsumed();
     releaseImageDataWhenConsumed_ = flagValue;
@@ -956,7 +974,7 @@ bool ReactNativeFeatureFlagsAccessor::shouldPressibilityUseW3CPointerEventsForHo
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(51, "shouldPressibilityUseW3CPointerEventsForHover");
+    markFlagAsAccessed(52, "shouldPressibilityUseW3CPointerEventsForHover");
 
     flagValue = currentProvider_->shouldPressibilityUseW3CPointerEventsForHover();
     shouldPressibilityUseW3CPointerEventsForHover_ = flagValue;
@@ -974,7 +992,7 @@ bool ReactNativeFeatureFlagsAccessor::skipActivityIdentityAssertionOnHostPause()
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(52, "skipActivityIdentityAssertionOnHostPause");
+    markFlagAsAccessed(53, "skipActivityIdentityAssertionOnHostPause");
 
     flagValue = currentProvider_->skipActivityIdentityAssertionOnHostPause();
     skipActivityIdentityAssertionOnHostPause_ = flagValue;
@@ -992,7 +1010,7 @@ bool ReactNativeFeatureFlagsAccessor::sweepActiveTouchOnChildNativeGesturesAndro
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(53, "sweepActiveTouchOnChildNativeGesturesAndroid");
+    markFlagAsAccessed(54, "sweepActiveTouchOnChildNativeGesturesAndroid");
 
     flagValue = currentProvider_->sweepActiveTouchOnChildNativeGesturesAndroid();
     sweepActiveTouchOnChildNativeGesturesAndroid_ = flagValue;
@@ -1010,7 +1028,7 @@ bool ReactNativeFeatureFlagsAccessor::traceTurboModulePromiseRejectionsOnAndroid
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(54, "traceTurboModulePromiseRejectionsOnAndroid");
+    markFlagAsAccessed(55, "traceTurboModulePromiseRejectionsOnAndroid");
 
     flagValue = currentProvider_->traceTurboModulePromiseRejectionsOnAndroid();
     traceTurboModulePromiseRejectionsOnAndroid_ = flagValue;
@@ -1028,7 +1046,7 @@ bool ReactNativeFeatureFlagsAccessor::updateRuntimeShadowNodeReferencesOnCommit(
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(55, "updateRuntimeShadowNodeReferencesOnCommit");
+    markFlagAsAccessed(56, "updateRuntimeShadowNodeReferencesOnCommit");
 
     flagValue = currentProvider_->updateRuntimeShadowNodeReferencesOnCommit();
     updateRuntimeShadowNodeReferencesOnCommit_ = flagValue;
@@ -1046,7 +1064,7 @@ bool ReactNativeFeatureFlagsAccessor::useAlwaysAvailableJSErrorHandling() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(56, "useAlwaysAvailableJSErrorHandling");
+    markFlagAsAccessed(57, "useAlwaysAvailableJSErrorHandling");
 
     flagValue = currentProvider_->useAlwaysAvailableJSErrorHandling();
     useAlwaysAvailableJSErrorHandling_ = flagValue;
@@ -1064,7 +1082,7 @@ bool ReactNativeFeatureFlagsAccessor::useFabricInterop() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(57, "useFabricInterop");
+    markFlagAsAccessed(58, "useFabricInterop");
 
     flagValue = currentProvider_->useFabricInterop();
     useFabricInterop_ = flagValue;
@@ -1082,7 +1100,7 @@ bool ReactNativeFeatureFlagsAccessor::useNativeEqualsInNativeReadableArrayAndroi
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(58, "useNativeEqualsInNativeReadableArrayAndroid");
+    markFlagAsAccessed(59, "useNativeEqualsInNativeReadableArrayAndroid");
 
     flagValue = currentProvider_->useNativeEqualsInNativeReadableArrayAndroid();
     useNativeEqualsInNativeReadableArrayAndroid_ = flagValue;
@@ -1100,7 +1118,7 @@ bool ReactNativeFeatureFlagsAccessor::useNativeTransformHelperAndroid() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(59, "useNativeTransformHelperAndroid");
+    markFlagAsAccessed(60, "useNativeTransformHelperAndroid");
 
     flagValue = currentProvider_->useNativeTransformHelperAndroid();
     useNativeTransformHelperAndroid_ = flagValue;
@@ -1118,7 +1136,7 @@ bool ReactNativeFeatureFlagsAccessor::useNativeViewConfigsInBridgelessMode() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(60, "useNativeViewConfigsInBridgelessMode");
+    markFlagAsAccessed(61, "useNativeViewConfigsInBridgelessMode");
 
     flagValue = currentProvider_->useNativeViewConfigsInBridgelessMode();
     useNativeViewConfigsInBridgelessMode_ = flagValue;
@@ -1136,7 +1154,7 @@ bool ReactNativeFeatureFlagsAccessor::useOptimizedEventBatchingOnAndroid() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(61, "useOptimizedEventBatchingOnAndroid");
+    markFlagAsAccessed(62, "useOptimizedEventBatchingOnAndroid");
 
     flagValue = currentProvider_->useOptimizedEventBatchingOnAndroid();
     useOptimizedEventBatchingOnAndroid_ = flagValue;
@@ -1154,7 +1172,7 @@ bool ReactNativeFeatureFlagsAccessor::useRawPropsJsiValue() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(62, "useRawPropsJsiValue");
+    markFlagAsAccessed(63, "useRawPropsJsiValue");
 
     flagValue = currentProvider_->useRawPropsJsiValue();
     useRawPropsJsiValue_ = flagValue;
@@ -1172,7 +1190,7 @@ bool ReactNativeFeatureFlagsAccessor::useShadowNodeStateOnClone() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(63, "useShadowNodeStateOnClone");
+    markFlagAsAccessed(64, "useShadowNodeStateOnClone");
 
     flagValue = currentProvider_->useShadowNodeStateOnClone();
     useShadowNodeStateOnClone_ = flagValue;
@@ -1190,7 +1208,7 @@ bool ReactNativeFeatureFlagsAccessor::useTurboModuleInterop() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(64, "useTurboModuleInterop");
+    markFlagAsAccessed(65, "useTurboModuleInterop");
 
     flagValue = currentProvider_->useTurboModuleInterop();
     useTurboModuleInterop_ = flagValue;
@@ -1208,7 +1226,7 @@ bool ReactNativeFeatureFlagsAccessor::useTurboModules() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(65, "useTurboModules");
+    markFlagAsAccessed(66, "useTurboModules");
 
     flagValue = currentProvider_->useTurboModules();
     useTurboModules_ = flagValue;
@@ -1217,6 +1235,24 @@ bool ReactNativeFeatureFlagsAccessor::useTurboModules() {
   return flagValue.value();
 }
 
+double ReactNativeFeatureFlagsAccessor::virtualViewHysteresisRatio() {
+  auto flagValue = virtualViewHysteresisRatio_.load();
+
+  if (!flagValue.has_value()) {
+    // This block is not exclusive but it is not necessary.
+    // If multiple threads try to initialize the feature flag, we would only
+    // be accessing the provider multiple times but the end state of this
+    // instance and the returned flag value would be the same.
+
+    markFlagAsAccessed(67, "virtualViewHysteresisRatio");
+
+    flagValue = currentProvider_->virtualViewHysteresisRatio();
+    virtualViewHysteresisRatio_ = flagValue;
+  }
+
+  return flagValue.value();
+}
+
 double ReactNativeFeatureFlagsAccessor::virtualViewPrerenderRatio() {
   auto flagValue = virtualViewPrerenderRatio_.load();
 
@@ -1226,7 +1262,7 @@ double ReactNativeFeatureFlagsAccessor::virtualViewPrerenderRatio() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(66, "virtualViewPrerenderRatio");
+    markFlagAsAccessed(68, "virtualViewPrerenderRatio");
 
     flagValue = currentProvider_->virtualViewPrerenderRatio();
     virtualViewPrerenderRatio_ = flagValue;

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsAccessor.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<e7ebd228905c959f5472fba72bc3f99c>>
+ * @generated SignedSource<<f1eb31a7412bff743a5c581224d71e2a>>
  */
 
 /**
@@ -70,6 +70,7 @@ class ReactNativeFeatureFlagsAccessor {
   bool enableResourceTimingAPI();
   bool enableViewCulling();
   bool enableViewRecycling();
+  bool enableViewRecyclingForScrollView();
   bool enableViewRecyclingForText();
   bool enableViewRecyclingForView();
   bool enableVirtualViewDebugFeatures();
@@ -98,6 +99,7 @@ class ReactNativeFeatureFlagsAccessor {
   bool useShadowNodeStateOnClone();
   bool useTurboModuleInterop();
   bool useTurboModules();
+  double virtualViewHysteresisRatio();
   double virtualViewPrerenderRatio();
 
   void override(std::unique_ptr<ReactNativeFeatureFlagsProvider> provider);
@@ -110,7 +112,7 @@ class ReactNativeFeatureFlagsAccessor {
   std::unique_ptr<ReactNativeFeatureFlagsProvider> currentProvider_;
   bool wasOverridden_;
 
-  std::array<std::atomic<const char*>, 67> accessedFeatureFlags_;
+  std::array<std::atomic<const char*>, 69> accessedFeatureFlags_;
 
   std::atomic<std::optional<bool>> commonTestFlag_;
   std::atomic<std::optional<bool>> cdpInteractionMetricsEnabled_;
@@ -150,6 +152,7 @@ class ReactNativeFeatureFlagsAccessor {
   std::atomic<std::optional<bool>> enableResourceTimingAPI_;
   std::atomic<std::optional<bool>> enableViewCulling_;
   std::atomic<std::optional<bool>> enableViewRecycling_;
+  std::atomic<std::optional<bool>> enableViewRecyclingForScrollView_;
   std::atomic<std::optional<bool>> enableViewRecyclingForText_;
   std::atomic<std::optional<bool>> enableViewRecyclingForView_;
   std::atomic<std::optional<bool>> enableVirtualViewDebugFeatures_;
@@ -178,6 +181,7 @@ class ReactNativeFeatureFlagsAccessor {
   std::atomic<std::optional<bool>> useShadowNodeStateOnClone_;
   std::atomic<std::optional<bool>> useTurboModuleInterop_;
   std::atomic<std::optional<bool>> useTurboModules_;
+  std::atomic<std::optional<double>> virtualViewHysteresisRatio_;
   std::atomic<std::optional<double>> virtualViewPrerenderRatio_;
 };
 

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsDefaults.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<a7f5d45347dee3c9c5b17731e1bf8993>>
+ * @generated SignedSource<<a76f1a1e8ba0d65b689b4b87d33d7ced>>
  */
 
 /**
@@ -179,6 +179,10 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
     return false;
   }
 
+  bool enableViewRecyclingForScrollView() override {
+    return false;
+  }
+
   bool enableViewRecyclingForText() override {
     return true;
   }
@@ -260,11 +264,11 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
   }
 
   bool useNativeEqualsInNativeReadableArrayAndroid() override {
-    return false;
+    return true;
   }
 
   bool useNativeTransformHelperAndroid() override {
-    return false;
+    return true;
   }
 
   bool useNativeViewConfigsInBridgelessMode() override {
@@ -276,7 +280,7 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
   }
 
   bool useRawPropsJsiValue() override {
-    return false;
+    return true;
   }
 
   bool useShadowNodeStateOnClone() override {
@@ -291,6 +295,10 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
     return false;
   }
 
+  double virtualViewHysteresisRatio() override {
+    return 0.0;
+  }
+
   double virtualViewPrerenderRatio() override {
     return 5.0;
   }

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsDynamicProvider.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<60b81844a9af1862b27ed6b4d9be5f59>>
+ * @generated SignedSource<<e2a5086e5586caf4c90ef503416a0e83>>
  */
 
 /**
@@ -387,6 +387,15 @@ class ReactNativeFeatureFlagsDynamicProvider : public ReactNativeFeatureFlagsDef
     return ReactNativeFeatureFlagsDefaults::enableViewRecycling();
   }
 
+  bool enableViewRecyclingForScrollView() override {
+    auto value = values_["enableViewRecyclingForScrollView"];
+    if (!value.isNull()) {
+      return value.getBool();
+    }
+
+    return ReactNativeFeatureFlagsDefaults::enableViewRecyclingForScrollView();
+  }
+
   bool enableViewRecyclingForText() override {
     auto value = values_["enableViewRecyclingForText"];
     if (!value.isNull()) {
@@ -639,6 +648,15 @@ class ReactNativeFeatureFlagsDynamicProvider : public ReactNativeFeatureFlagsDef
     return ReactNativeFeatureFlagsDefaults::useTurboModules();
   }
 
+  double virtualViewHysteresisRatio() override {
+    auto value = values_["virtualViewHysteresisRatio"];
+    if (!value.isNull()) {
+      return value.getDouble();
+    }
+
+    return ReactNativeFeatureFlagsDefaults::virtualViewHysteresisRatio();
+  }
+
   double virtualViewPrerenderRatio() override {
     auto value = values_["virtualViewPrerenderRatio"];
     if (!value.isNull()) {

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsOverridesOSSExperimental.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c9b7b95d3cc3fed879476f191a60d3f2>>
+ * @generated SignedSource<<77870f0db494c7b6932950a1fa475fdc>>
  */
 
 /**
@@ -34,14 +34,6 @@ class ReactNativeFeatureFlagsOverridesOSSExperimental : public ReactNativeFeatur
   bool preventShadowTreeCommitExhaustion() override {
     return true;
   }
-
-  bool useNativeEqualsInNativeReadableArrayAndroid() override {
-    return true;
-  }
-
-  bool useNativeTransformHelperAndroid() override {
-    return true;
-  }
 };
 
 } // namespace facebook::react

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlagsProvider.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<56fe64198dddcba67062ef52a180128e>>
+ * @generated SignedSource<<feb44bb7ec97d29787eac070103f9e1b>>
  */
 
 /**
@@ -63,6 +63,7 @@ class ReactNativeFeatureFlagsProvider {
   virtual bool enableResourceTimingAPI() = 0;
   virtual bool enableViewCulling() = 0;
   virtual bool enableViewRecycling() = 0;
+  virtual bool enableViewRecyclingForScrollView() = 0;
   virtual bool enableViewRecyclingForText() = 0;
   virtual bool enableViewRecyclingForView() = 0;
   virtual bool enableVirtualViewDebugFeatures() = 0;
@@ -91,6 +92,7 @@ class ReactNativeFeatureFlagsProvider {
   virtual bool useShadowNodeStateOnClone() = 0;
   virtual bool useTurboModuleInterop() = 0;
   virtual bool useTurboModules() = 0;
+  virtual double virtualViewHysteresisRatio() = 0;
   virtual double virtualViewPrerenderRatio() = 0;
 };
 

packages/react-native/ReactCommon/react/nativemodule/featureflags/NativeReactNativeFeatureFlags.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<3c321b78f9d710e5f3dc3a73e56be298>>
+ * @generated SignedSource<<c9c36c1dbece9e27f7b71da7611cb747>>
  */
 
 /**
@@ -234,6 +234,11 @@ bool NativeReactNativeFeatureFlags::enableViewRecycling(
   return ReactNativeFeatureFlags::enableViewRecycling();
 }
 
+bool NativeReactNativeFeatureFlags::enableViewRecyclingForScrollView(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::enableViewRecyclingForScrollView();
+}
+
 bool NativeReactNativeFeatureFlags::enableViewRecyclingForText(
     jsi::Runtime& /*runtime*/) {
   return ReactNativeFeatureFlags::enableViewRecyclingForText();
@@ -374,6 +379,11 @@ bool NativeReactNativeFeatureFlags::useTurboModules(
   return ReactNativeFeatureFlags::useTurboModules();
 }
 
+double NativeReactNativeFeatureFlags::virtualViewHysteresisRatio(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::virtualViewHysteresisRatio();
+}
+
 double NativeReactNativeFeatureFlags::virtualViewPrerenderRatio(
     jsi::Runtime& /*runtime*/) {
   return ReactNativeFeatureFlags::virtualViewPrerenderRatio();

packages/react-native/ReactCommon/react/nativemodule/featureflags/NativeReactNativeFeatureFlags.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<15625838a3b9e9ecf3e77940a5f019a6>>
+ * @generated SignedSource<<320e69fa54228a352fad210e3a43b947>>
  */
 
 /**
@@ -112,6 +112,8 @@ class NativeReactNativeFeatureFlags
 
   bool enableViewRecycling(jsi::Runtime& runtime);
 
+  bool enableViewRecyclingForScrollView(jsi::Runtime& runtime);
+
   bool enableViewRecyclingForText(jsi::Runtime& runtime);
 
   bool enableViewRecyclingForView(jsi::Runtime& runtime);
@@ -168,6 +170,8 @@ class NativeReactNativeFeatureFlags
 
   bool useTurboModules(jsi::Runtime& runtime);
 
+  double virtualViewHysteresisRatio(jsi::Runtime& runtime);
+
   double virtualViewPrerenderRatio(jsi::Runtime& runtime);
 };
 

packages/react-native/ReactCommon/react/renderer/components/switch/iosswitch/react/renderer/components/switch/IOSSwitchShadowNode.mm

@@ -20,7 +20,9 @@ Size SwitchShadowNode::measureContent(
     const LayoutConstraints & /*layoutConstraints*/) const
 {
   CGSize uiSwitchSize = RCTSwitchSize();
-  return {.width = uiSwitchSize.width, .height = uiSwitchSize.height};
+  // Apple has some error when returning the width of the component and it doesn't
+  // account for the borders.
+  return {.width = uiSwitchSize.width + 2, .height = uiSwitchSize.height};
 }
 
 } // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/graphics/platform/ios/react/renderer/graphics/RCTPlatformColorUtils.mm

@@ -184,7 +184,7 @@ static inline facebook::react::ColorComponents _ColorComponentsFromUIColor(UICol
 {
   CGFloat rgba[4];
   [color getRed:&rgba[0] green:&rgba[1] blue:&rgba[2] alpha:&rgba[3]];
-  return {(float)rgba[0], (float)rgba[1], (float)rgba[2], (float)rgba[3]};
+  return {.red = (float)rgba[0], .green = (float)rgba[1], .blue = (float)rgba[2], .alpha = (float)rgba[3]};
 }
 
 facebook::react::ColorComponents RCTPlatformColorComponentsFromSemanticItems(std::vector<std::string> &semanticItems)

packages/react-native/ReactCommon/react/renderer/mounting/Differentiator.cpp

@@ -126,6 +126,8 @@ static void calculateShadowViewMutations(
     const CullingContext& oldCullingContext = {},
     const CullingContext& newCullingContext = {});
 
+namespace {
+
 struct OrderedMutationInstructionContainer {
   ShadowViewMutation::List createMutations{};
   ShadowViewMutation::List deleteMutations{};
@@ -136,6 +138,8 @@ struct OrderedMutationInstructionContainer {
   ShadowViewMutation::List destructiveDownwardMutations{};
 };
 
+} // namespace
+
 static void updateMatchedPairSubtrees(
     ViewNodePairScope& scope,
     OrderedMutationInstructionContainer& mutationContainer,

packages/react-native/ReactCommon/react/renderer/textlayoutmanager/platform/ios/react/renderer/textlayoutmanager/RCTTextLayoutManager.mm

@@ -187,34 +187,36 @@ static NSLineBreakMode RCTNSLineBreakModeFromEllipsizeMode(EllipsizeMode ellipsi
   std::vector<LineMeasurement> paragraphLines{};
   auto blockParagraphLines = &paragraphLines;
 
-  [layoutManager enumerateLineFragmentsForGlyphRange:glyphRange
-                                          usingBlock:^(
-                                              CGRect overallRect,
-                                              CGRect usedRect,
-                                              NSTextContainer *_Nonnull usedTextContainer,
-                                              NSRange lineGlyphRange,
-                                              BOOL *_Nonnull stop) {
-                                            NSRange range = [layoutManager characterRangeForGlyphRange:lineGlyphRange
-                                                                                      actualGlyphRange:nil];
-                                            NSString *renderedString = [textStorage.string substringWithRange:range];
-                                            UIFont *font = [[textStorage attributedSubstringFromRange:range]
-                                                     attribute:NSFontAttributeName
-                                                       atIndex:0
-                                                effectiveRange:nil];
-                                            auto rect = facebook::react::Rect{
-                                                facebook::react::Point{usedRect.origin.x, usedRect.origin.y},
-                                                facebook::react::Size{usedRect.size.width, usedRect.size.height}};
+  [layoutManager
+      enumerateLineFragmentsForGlyphRange:glyphRange
+                               usingBlock:^(
+                                   CGRect overallRect,
+                                   CGRect usedRect,
+                                   NSTextContainer *_Nonnull usedTextContainer,
+                                   NSRange lineGlyphRange,
+                                   BOOL *_Nonnull stop) {
+                                 NSRange range = [layoutManager characterRangeForGlyphRange:lineGlyphRange
+                                                                           actualGlyphRange:nil];
+                                 NSString *renderedString = [textStorage.string substringWithRange:range];
+                                 UIFont *font =
+                                     [[textStorage attributedSubstringFromRange:range] attribute:NSFontAttributeName
+                                                                                         atIndex:0
+                                                                                  effectiveRange:nil];
+                                 auto rect = facebook::react::Rect{
+                                     .origin = facebook::react::Point{.x = usedRect.origin.x, .y = usedRect.origin.y},
+                                     .size = facebook::react::Size{
+                                         .width = usedRect.size.width, .height = usedRect.size.height}};
 
-                                            CGFloat baseline = [layoutManager locationForGlyphAtIndex:range.location].y;
-                                            auto line = LineMeasurement{
-                                                std::string([renderedString UTF8String]),
-                                                rect,
-                                                overallRect.size.height - baseline,
-                                                font.capHeight,
-                                                baseline,
-                                                font.xHeight};
-                                            blockParagraphLines->push_back(line);
-                                          }];
+                                 CGFloat baseline = [layoutManager locationForGlyphAtIndex:range.location].y;
+                                 auto line = LineMeasurement{
+                                     std::string([renderedString UTF8String]),
+                                     rect,
+                                     overallRect.size.height - baseline,
+                                     font.capHeight,
+                                     baseline,
+                                     font.xHeight};
+                                 blockParagraphLines->push_back(line);
+                               }];
   return paragraphLines;
 }
 
@@ -416,19 +418,20 @@ static NSLineBreakMode RCTNSLineBreakModeFromEllipsizeMode(EllipsizeMode ellipsi
                                                                                      atIndex:0
                                                                               effectiveRange:nil];
                   frame = {
-                      {glyphRect.origin.x,
-                       glyphRect.origin.y + glyphRect.size.height - attachmentSize.height + font.descender},
-                      attachmentSize};
+                      .origin =
+                          {glyphRect.origin.x,
+                           glyphRect.origin.y + glyphRect.size.height - attachmentSize.height + font.descender},
+                      .size = attachmentSize};
 
                   auto rect = facebook::react::Rect{
-                      facebook::react::Point{frame.origin.x, frame.origin.y},
-                      facebook::react::Size{frame.size.width, frame.size.height}};
+                      .origin = facebook::react::Point{.x = frame.origin.x, .y = frame.origin.y},
+                      .size = facebook::react::Size{.width = frame.size.width, .height = frame.size.height}};
 
                   attachments.push_back(TextMeasurement::Attachment{.frame = rect, .isClipped = false});
                 }
               }];
 
-  return TextMeasurement{{size.width, size.height}, attachments};
+  return TextMeasurement{.size = {.width = size.width, .height = size.height}, .attachments = attachments};
 }
 
 @end

packages/react-native/ReactCommon/react/renderer/textlayoutmanager/platform/ios/react/renderer/textlayoutmanager/TextLayoutManager.mm

@@ -39,23 +39,27 @@ TextMeasurement TextLayoutManager::measure(
     case AttributedStringBox::Mode::Value: {
       auto attributedString = ensurePlaceholderIfEmpty_DO_NOT_USE(attributedStringBox.getValue());
 
-      measurement = textMeasureCache_.get({attributedString, paragraphAttributes, layoutConstraints}, [&]() {
-        auto telemetry = TransactionTelemetry::threadLocalTelemetry();
-        if (telemetry) {
-          telemetry->willMeasureText();
-        }
+      measurement = textMeasureCache_.get(
+          {.attributedString = attributedString,
+           .paragraphAttributes = paragraphAttributes,
+           .layoutConstraints = layoutConstraints},
+          [&]() {
+            auto telemetry = TransactionTelemetry::threadLocalTelemetry();
+            if (telemetry) {
+              telemetry->willMeasureText();
+            }
 
-        auto measurement = [textLayoutManager measureAttributedString:attributedString
-                                                  paragraphAttributes:paragraphAttributes
-                                                        layoutContext:layoutContext
-                                                    layoutConstraints:layoutConstraints];
+            auto measurement = [textLayoutManager measureAttributedString:attributedString
+                                                      paragraphAttributes:paragraphAttributes
+                                                            layoutContext:layoutContext
+                                                        layoutConstraints:layoutConstraints];
 
-        if (telemetry) {
-          telemetry->didMeasureText();
-        }
+            if (telemetry) {
+              telemetry->didMeasureText();
+            }
 
-        return measurement;
-      });
+            return measurement;
+          });
       break;
     }
 
@@ -96,12 +100,13 @@ LinesMeasurements TextLayoutManager::measureLines(
 
   RCTTextLayoutManager *textLayoutManager = (RCTTextLayoutManager *)unwrapManagedObject(nativeTextLayoutManager_);
 
-  auto measurement = lineMeasureCache_.get({attributedString, paragraphAttributes, size}, [&]() {
-    auto measurement = [textLayoutManager getLinesForAttributedString:attributedString
-                                                  paragraphAttributes:paragraphAttributes
-                                                                 size:{size.width, size.height}];
-    return measurement;
-  });
+  auto measurement = lineMeasureCache_.get(
+      {.attributedString = attributedString, .paragraphAttributes = paragraphAttributes, .size = size}, [&]() {
+        auto measurement = [textLayoutManager getLinesForAttributedString:attributedString
+                                                      paragraphAttributes:paragraphAttributes
+                                                                     size:{size.width, size.height}];
+        return measurement;
+      });
 
   return measurement;
 }

packages/react-native/ReactCommon/reactperflogger/reactperflogger/FuseboxPerfettoDataSource.cpp

@@ -27,8 +27,6 @@ const std::string JS_SAMPLING_TRACK = "JS Sampling";
 
 const int SAMPLING_HZ = 1000;
 
-using perfetto::TrackEvent;
-
 #if defined(__ANDROID__)
 std::string getApplicationId() {
   pid_t pid = getpid();

packages/react-native/ReactCommon/reactperflogger/reactperflogger/HermesPerfettoDataSource.cpp

@@ -23,8 +23,6 @@ const int SAMPLING_HZ = 100;
 
 int64_t hermesDeltaTime = 0;
 
-using perfetto::TrackEvent;
-
 uint64_t hermesToPerfettoTime(int64_t hermesTs) {
   if (hermesDeltaTime == 0) {
     hermesDeltaTime = TrackEvent::GetTraceTimeNs() -
@@ -113,7 +111,7 @@ void HermesPerfettoDataSource::OnStart(const StartArgs&) {
       "react-native",
       perfetto::DynamicString{"Profiling Started"},
       getPerfettoWebPerfTrackSync("JS Sampling"),
-      perfetto::TrackEvent::GetTraceTimeNs());
+      TrackEvent::GetTraceTimeNs());
 }
 
 void HermesPerfettoDataSource::OnFlush(const FlushArgs&) {

packages/react-native/ReactCommon/reactperflogger/reactperflogger/ReactPerfetto.cpp

@@ -29,7 +29,7 @@ void initializePerfetto() {
     args.backends |= perfetto::kSystemBackend;
     args.use_monotonic_clock = true;
     perfetto::Tracing::Initialize(args);
-    perfetto::TrackEvent::Register();
+    TrackEvent::Register();
   });
 
   HermesPerfettoDataSource::RegisterDataSource();
@@ -42,7 +42,7 @@ static perfetto::Track createTrack(const std::string& trackName) {
   auto track = perfetto::Track(trackId++);
   auto desc = track.Serialize();
   desc.set_name(trackName);
-  perfetto::TrackEvent::SetTrackDescriptor(track, desc);
+  TrackEvent::SetTrackDescriptor(track, desc);
   return track;
 }