xplat/js/react-native-github/packages/react-native/ReactCommon/jsinspector-modern/Base64.h

Reviewed By: javache

Differential Revision: D82005121

.github/workflows/create-release.yml

@@ -19,6 +19,7 @@ on:
 
 jobs:
   create_release:
+    if: github.repository == 'facebook/react-native'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout

.github/workflows/nightly.yml

@@ -23,6 +23,7 @@ jobs:
 
   prepare_hermes_workspace:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     env:
       HERMES_WS_DIR: /tmp/hermes
       HERMES_VERSION_FILE: packages/react-native/sdks/.hermesversion
@@ -50,8 +51,8 @@ jobs:
       - name: Build HermesC Apple
         uses: ./.github/actions/build-hermesc-apple
         with:
-          hermes-version: ${{ needs.prepare_hermes_workspace.output.hermes-version }}
-          react-native-version: ${{ needs.prepare_hermes_workspace.output.react-native-version }}
+          hermes-version: ${{ needs.prepare_hermes_workspace.outputs.hermes-version }}
+          react-native-version: ${{ needs.prepare_hermes_workspace.outputs.react-native-version }}
 
   build_apple_slices_hermes:
     runs-on: macos-14
@@ -75,7 +76,7 @@ jobs:
         uses: ./.github/actions/build-apple-slices-hermes
         with:
           flavor: ${{ matrix.flavor }}
-          slice: ${{ matrix.slice}}
+          slice: ${{ matrix.slice }}
           hermes-version: ${{ needs.prepare_hermes_workspace.outputs.hermes-version }}
           react-native-version: ${{ needs.prepare_hermes_workspace.outputs.react-native-version }}
 
@@ -101,6 +102,7 @@ jobs:
           flavor: ${{ matrix.flavor }}
 
   prebuild_apple_dependencies:
+    if: github.repository == 'facebook/react-native'
     uses: ./.github/workflows/prebuild-ios-dependencies.yml
     secrets: inherit
 
@@ -145,6 +147,7 @@ jobs:
 
   build_android:
     runs-on: 8-core-ubuntu
+    if: github.repository == 'facebook/react-native'
     needs: [set_release_type]
     container:
       image: reactnativecommunity/react-native-android:latest

.github/workflows/publish-bumped-packages.yml

@@ -9,6 +9,7 @@ on:
 jobs:
   publish_bumped_packages:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     env:
       GHA_NPM_TOKEN: ${{ secrets.GHA_NPM_TOKEN }}
     steps:

.github/workflows/publish-release.yml

@@ -21,6 +21,7 @@ jobs:
 
   prepare_hermes_workspace:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     env:
       HERMES_WS_DIR: /tmp/hermes
       HERMES_VERSION_FILE: packages/react-native/sdks/.hermesversion
@@ -98,6 +99,7 @@ jobs:
           flavor: ${{ matrix.flavor }}
 
   prebuild_apple_dependencies:
+    if: github.repository == 'facebook/react-native'
     uses: ./.github/workflows/prebuild-ios-dependencies.yml
     secrets: inherit
 

.github/workflows/retry-workflow.yml

@@ -9,6 +9,7 @@ on:
 jobs:
     rerun:
         runs-on: ubuntu-latest
+        if: github.repository == 'facebook/react-native'
         steps:
             - name: rerun ${{ inputs.run_id }}
               env:

.github/workflows/test-all.yml

@@ -11,6 +11,7 @@ on:
 jobs:
   set_release_type:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     outputs:
       RELEASE_TYPE: ${{ steps.set_release_type.outputs.RELEASE_TYPE }}
     env:
@@ -34,6 +35,7 @@ jobs:
 
   prepare_hermes_workspace:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     env:
       HERMES_WS_DIR: /tmp/hermes
       HERMES_VERSION_FILE: packages/react-native/sdks/.hermesversion
@@ -112,6 +114,7 @@ jobs:
           flavor: ${{ matrix.flavor }}
 
   prebuild_apple_dependencies:
+    if: github.repository == 'facebook/react-native'
     uses: ./.github/workflows/prebuild-ios-dependencies.yml
     secrets: inherit
 
@@ -594,6 +597,7 @@ jobs:
 
   test_js:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     strategy:
       fail-fast: false
       matrix:
@@ -608,6 +612,7 @@ jobs:
 
   lint:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:

.github/workflows/validate-dotslash-artifacts.yml

@@ -27,6 +27,7 @@ on:
 jobs:
   validate-dotslash-artifacts:
     runs-on: ubuntu-latest
+    if: github.repository == 'facebook/react-native'
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

CHANGELOG.md

@@ -1,5 +1,37 @@
 # Changelog
 
+## v0.82.0-rc.1
+
+### Added
+
+#### Android specific
+
+- **Hermes V1:** Added opt-in to use the new Hermes ([3e9990f860](https://github.com/facebook/react-native/commit/3e9990f860eb9380837ef431ca02def32c4261ad) by [@j-piasecki](https://github.com/j-piasecki))
+
+#### iOS specific
+
+- **Hermes V1:** Added opt-in to use the new Hermes ([e9cdc308b4](https://github.com/facebook/react-native/commit/e9cdc308b4c04753d85757e8877ac00c3c687b95) by [@j-piasecki](https://github.com/j-piasecki))
+
+### Changed
+
+- **Hermes V1:** Changed the source of hermesc binary to be an npm package ([2e0bd13a25](https://github.com/facebook/react-native/commit/2e0bd13a2533fe7ab64125a95b9215b806018c6e) by [@j-piasecki](https://github.com/j-piasecki))
+
+### Deprecated
+
+- **APIs:** Deprecate legacy javascript react native apis ([e7aeea26bd](https://github.com/facebook/react-native/commit/e7aeea26bde6e9cda0a3a0a55fc2a0421fb0c0e5) by [@RSNara](https://github.com/RSNara))
+
+### Fixed
+
+#### Android specific
+
+- **Build From Source:** Fix build from source due to missing folder error on Gradle 9.0 ([9fbce3eff1](https://github.com/facebook/react-native/commit/9fbce3eff18060f16e796badc415ba733ede19af) by [@cortinico](https://github.com/cortinico))
+
+#### iOS specific
+
+- **RCTAlertController:** Simplify RCTAlertController, don't create additional UIWindow ([05c4321b19](https://github.com/facebook/react-native/commit/05c4321b194c3d0e146b6085bcaccc75acd3fd67) by [@okwasniewski](https://github.com/okwasniewski))
+- **Prebuild:** Fix Node scripts related to prebuilt tarball extraction for paths containing whitespaces ([9731e8ebc5](https://github.com/facebook/react-native/commit/9731e8ebc5ea87526a91b9903172639e062cd920) by [@kitten](https://github.com/kitten))
+- **Prebuild:** Use autolinking-generated react-native-config output in second step of cocoapods linking that generates artifacts and generated source ([f170db412b](https://github.com/facebook/react-native/commit/f170db412b3ab46fd0894d5d66431d9c230cd3a8) by [@kitten](https://github.com/kitten))
+
 ## v0.82.0-rc.0
 
 ### Breaking

README.md

@@ -17,10 +17,13 @@
     <img src="https://img.shields.io/npm/v/react-native?color=brightgreen&label=npm%20package" alt="Current npm package version." />
   </a>
   <a href="https://reactnative.dev/docs/contributing">
-    <img src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg" alt="PRs welcome!" />
+    <img src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg" alt="PRs are welcome!" />
   </a>
   <a href="https://twitter.com/intent/follow?screen_name=reactnative">
-    <img src="https://img.shields.io/twitter/follow/reactnative.svg?label=Follow%20@reactnative" alt="Follow @reactnative" />
+    <img src="https://img.shields.io/twitter/follow/reactnative.svg?label=Follow%20@reactnative" alt="Follow @reactnative on X" />
+  </a>
+  <a href="https://bsky.app/profile/reactnative.dev">
+    <img src="https://img.shields.io/badge/Bluesky-0285FF?logo=bluesky&logoColor=fff" alt="Follow @reactnative.dev on Bluesky" />
   </a>
 </p>
 

package.json

@@ -100,7 +100,7 @@
     "jsonc-parser": "2.2.1",
     "markdownlint-cli2": "^0.17.2",
     "markdownlint-rule-relative-links": "^3.0.0",
-    "memfs": "^4.7.7",
+    "memfs": "^4.38.2",
     "metro-babel-register": "^0.83.1",
     "metro-transform-plugins": "^0.83.1",
     "micromatch": "^4.0.4",

packages/gradle-plugin/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/utils/ProjectUtils.kt

@@ -23,6 +23,7 @@ import com.facebook.react.utils.PropertyUtils.SCOPED_USE_THIRD_PARTY_JSC
 import com.facebook.react.utils.PropertyUtils.USE_THIRD_PARTY_JSC
 import org.gradle.api.Project
 import org.gradle.api.file.DirectoryProperty
+import org.jetbrains.kotlin.gradle.plugin.extraProperties
 
 internal object ProjectUtils {
 
@@ -75,7 +76,11 @@ internal object ProjectUtils {
         (project.hasProperty(HERMES_V1_ENABLED) &&
             project.property(HERMES_V1_ENABLED).toString().toBoolean()) ||
             (project.hasProperty(SCOPED_HERMES_V1_ENABLED) &&
-                project.property(SCOPED_HERMES_V1_ENABLED).toString().toBoolean())
+                project.property(SCOPED_HERMES_V1_ENABLED).toString().toBoolean()) ||
+            (project.extraProperties.has(HERMES_V1_ENABLED) &&
+                project.extraProperties.get(HERMES_V1_ENABLED).toString().toBoolean()) ||
+            (project.extraProperties.has(SCOPED_HERMES_V1_ENABLED) &&
+                project.extraProperties.get(SCOPED_HERMES_V1_ENABLED).toString().toBoolean())
 
   internal fun Project.needsCodegenFromPackageJson(rootProperty: DirectoryProperty): Boolean {
     val parsedPackageJson = readPackageJsonFile(this, rootProperty)

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

@@ -33,9 +33,9 @@ class GeneratePackageListTaskTest {
     val inputFile = tempFolder.newFile("config.json")
 
     val task =
-        createTestTask<GeneratePackageListTask> {
-          it.generatedOutputDirectory.set(outputFolder)
-          it.autolinkInputFile.set(inputFile)
+        createTestTask<GeneratePackageListTask> { testTask ->
+          testTask.generatedOutputDirectory.set(outputFolder)
+          testTask.autolinkInputFile.set(inputFile)
         }
 
     assertThat(task.inputs.files.singleFile).isEqualTo(inputFile)

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

@@ -82,11 +82,11 @@ class PrepareGflagsTaskTest {
     val gflagsThirdPartyPath = tempFolder.newFolder("gflagspath/jni")
     val output = tempFolder.newFolder("output")
     val task =
-        createTestTask<PrepareGflagsTask> {
-          it.gflagsPath.setFrom(gflagspath)
-          it.gflagsThirdPartyPath.set(gflagsThirdPartyPath)
-          it.gflagsVersion.set("1.0.0")
-          it.outputDir.set(output)
+        createTestTask<PrepareGflagsTask> { taskConfig ->
+          taskConfig.gflagsPath.setFrom(gflagspath)
+          taskConfig.gflagsThirdPartyPath.set(gflagsThirdPartyPath)
+          taskConfig.gflagsVersion.set("1.0.0")
+          taskConfig.outputDir.set(output)
         }
     File(gflagspath, "gflags-1.0.0/src/gflags_declare.h.in").apply {
       parentFile.mkdirs()

packages/gradle-plugin/shared-testutil/src/main/kotlin/com/facebook/react/tests/OsRule.kt

@@ -25,14 +25,14 @@ class OsRule : TestRule {
       override fun evaluate() {
         val annotation = description.annotations.filterIsInstance<WithOs>().firstOrNull()
 
-        annotation?.os?.propertyName?.let {
+        annotation?.os?.propertyName?.let { osName ->
           retainOs = System.getProperty(OS_NAME_KEY)
-          System.setProperty(OS_NAME_KEY, it)
+          System.setProperty(OS_NAME_KEY, osName)
         }
-        annotation?.arch?.let {
-          if (it.isNotBlank()) {
+        annotation?.arch?.let { arch ->
+          if (arch.isNotBlank()) {
             retainArch = System.getProperty(OS_ARCH_KEY)
-            System.setProperty(OS_ARCH_KEY, it)
+            System.setProperty(OS_ARCH_KEY, arch)
           }
         }
         try {

packages/react-native/Libraries/AppDelegate/RCTAppDelegate.h

@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#import <React/RCTBridgeDelegate.h>
-#import <React/RCTConvert.h>
 #import <UIKit/UIKit.h>
 #import "RCTDefaultReactNativeFactoryDelegate.h"
 #import "RCTReactNativeFactory.h"

packages/react-native/Libraries/AppDelegate/RCTAppDelegate.mm

@@ -6,6 +6,7 @@
  */
 
 #import "RCTAppDelegate.h"
+#import <React/RCTBridgeDelegate.h>
 #import <React/RCTLog.h>
 #import <React/RCTRootView.h>
 #import <React/RCTSurfacePresenterBridgeAdapter.h>

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

@@ -6,6 +6,7 @@
  *
  * @flow strict
  * @format
+ * @deprecated
  */
 
 'use strict';

packages/react-native/Libraries/BatchedBridge/MessageQueue.js

@@ -6,6 +6,7 @@
  *
  * @flow strict
  * @format
+ * @deprecated
  */
 
 'use strict';

packages/react-native/Libraries/Core/Timers/JSTimers.js

@@ -6,6 +6,7 @@
  *
  * @flow
  * @format
+ * @deprecated
  */
 
 import NativeTiming from './NativeTiming';

packages/react-native/Libraries/Core/Timers/NativeTiming.js

@@ -6,6 +6,7 @@
  *
  * @flow strict
  * @format
+ * @deprecated
  */
 
 export * from '../../../src/private/specs_DEPRECATED/modules/NativeTiming';

packages/react-native/Libraries/Core/Timers/immediateShim.js

@@ -6,6 +6,7 @@
  *
  * @flow
  * @format
+ * @deprecated
  */
 
 'use strict';

packages/react-native/Libraries/Network/RCTInspectorNetworkReporter.mm

@@ -10,9 +10,9 @@
 #import "RCTNetworkConversions.h"
 
 #import <React/RCTLog.h>
-#import <jsinspector-modern/network/NetworkReporter.h>
+#import <react/networking/NetworkReporter.h>
 
-using namespace facebook::react::jsinspector_modern;
+using namespace facebook::react;
 
 #ifdef REACT_NATIVE_DEBUGGER_ENABLED
 namespace {

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

@@ -7,7 +7,7 @@
  * @noformat
  * @nolint
  * @flow strict
- * @generated SignedSource<<deb7924d11c790f99448a1c2f0edddb9>>
+ * @generated SignedSource<<c0e57723772ea5f1aa8c3c897ac3c216>>
  */
 
 import type {
@@ -135,6 +135,7 @@ export type RenderRootOptions = {
     error: mixed,
     errorInfo: {+componentStack?: ?string},
   ) => void,
+  onDefaultTransitionIndicator?: () => void | (() => void),
 };
 
 /**

packages/react-native/Libraries/TypeSafety/RCTConvertHelpers.h

@@ -67,7 +67,7 @@ template <typename T>
 facebook::react::LazyVector<T> RCTBridgingToVec(id value, T (^ctor)(id element))
 {
   NSArray *array = RCTBridgingToArray(value);
-  typedef typename facebook::react::LazyVector<T>::size_type _size_t;
+  using _size_t = typename facebook::react::LazyVector<T>::size_type;
   _size_t size = static_cast<_size_t>(array.count);
   return facebook::react::LazyVector<T>::fromUnsafeRawValue(array, size, ctor);
 }

packages/react-native/Package.swift

@@ -211,6 +211,18 @@ let reactHermes = RNTarget(
   ]
 )
 
+/// React-networking.podspec
+let reactNetworking = RNTarget(
+  name: .reactNetworking,
+  path: "ReactCommon/react/networking",
+  excludedPaths: ["tests"],
+  dependencies: [.reactNativeDependencies, .reactJsInspectorNetwork, .reactPerformanceTimeline],
+  defines: [
+    CXXSetting.define("REACT_NATIVE_DEBUGGER_ENABLED", to: "1", .when(configuration: BuildConfiguration.debug)),
+    CXXSetting.define("REACT_NATIVE_DEBUGGER_ENABLED_DEVONLY", to: "1", .when(configuration: BuildConfiguration.debug)),
+  ]
+)
+
 /// React-performancecdpmetrics.podspec
 let reactPerformanceCdpMetrics = RNTarget(
   name: .reactPerformanceCdpMetrics,
@@ -304,6 +316,13 @@ let reactIdleCallbacksNativeModule = RNTarget(
   dependencies: [.reactNativeDependencies, .reactDebug, .reactFeatureFlags, .reactUtils, .reactPerfLogger, .reactCxxReact, .reactTurboModuleCore]
 )
 
+/// React-webperformance.podspec
+let reactWebPerformanceNativeModule = RNTarget(
+  name: .reactWebPerformanceNativeModule,
+  path: "ReactCommon/react/nativemodule/webperformance",
+  dependencies: [.reactNativeDependencies, .reactCxxReact, .reactTurboModuleCore, .reactPerformanceTimeline]
+)
+
 /// React-featureflagnativemodule.podspec
 let reactFeatureflagsNativemodule = RNTarget(
   name: .reactFeatureflagsNativemodule,
@@ -566,6 +585,7 @@ let targets = [
   reactNativeDependencies,
   hermesPrebuilt,
   reactJsiTooling,
+  reactNetworking,
   reactPerformanceCdpMetrics,
   reactPerformanceTimeline,
   reactRuntimeScheduler,
@@ -590,6 +610,7 @@ let targets = [
   reactTurboModuleCoreDefaults,
   reactTurboModuleCoreMicrotasks,
   reactIdleCallbacksNativeModule,
+  reactWebPerformanceNativeModule,
   reactFeatureflagsNativemodule,
   reactNativeModuleDom,
   reactAppDelegate,
@@ -737,6 +758,7 @@ extension String {
   static let hermesPrebuilt = "hermes-prebuilt"
 
   static let reactJsiTooling = "React-jsitooling"
+  static let reactNetworking = "React-networking"
   static let reactPerformanceCdpMetrics = "React-performancecdpmetrics"
   static let reactPerformanceTimeline = "React-performancetimeline"
   static let reactRuntimeScheduler = "React-runtimescheduler"
@@ -764,6 +786,7 @@ extension String {
   static let reactTurboModuleCoreDefaults = "ReactCommon/turbomodule/core/defaults"
   static let reactTurboModuleCoreMicrotasks = "ReactCommon/turbomodule/core/microtasks"
   static let reactIdleCallbacksNativeModule = "React-idlecallbacksnativemodule"
+  static let reactWebPerformanceNativeModule = "React-webperformancenativemodule"
   static let reactFeatureflagsNativemodule = "React-featureflagsnativemodule"
   static let reactNativeModuleDom = "React-domnativemodule"
   static let reactAppDelegate = "React-RCTAppDelegate"

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

@@ -721,13 +721,13 @@ NSData *__nullable RCTGzipData(NSData *__nullable input, float level)
 
   void *libz = dlopen("/usr/lib/libz.dylib", RTLD_LAZY);
 
-  typedef int (*DeflateInit2_)(z_streamp, int, int, int, int, int, const char *, int);
+  using DeflateInit2_ = int (*)(z_streamp, int, int, int, int, int, const char *, int);
   DeflateInit2_ deflateInit2_ = (DeflateInit2_)dlsym(libz, "deflateInit2_");
 
-  typedef int (*Deflate)(z_streamp, int);
+  using Deflate = int (*)(z_streamp, int);
   Deflate deflate = (Deflate)dlsym(libz, "deflate");
 
-  typedef int (*DeflateEnd)(z_streamp);
+  using DeflateEnd = int (*)(z_streamp);
   DeflateEnd deflateEnd = (DeflateEnd)dlsym(libz, "deflateEnd");
 
   z_stream stream;

packages/react-native/React/CoreModules/RCTDeviceInfo.mm

@@ -238,11 +238,10 @@ static NSDictionary *RCTExportedDimensions(CGFloat fontScale)
 - (void)interfaceOrientationDidChange
 {
 #if TARGET_OS_IOS && !TARGET_OS_MACCATALYST
-  UIApplication *application = RCTSharedApplication();
-  UIInterfaceOrientation nextOrientation = RCTKeyWindow().windowScene.interfaceOrientation;
+  UIWindow *window = RCTKeyWindow();
+  UIInterfaceOrientation nextOrientation = window.windowScene.interfaceOrientation;
 
-  BOOL isRunningInFullScreen =
-      CGRectEqualToRect(application.delegate.window.frame, application.delegate.window.screen.bounds);
+  BOOL isRunningInFullScreen = window ? CGRectEqualToRect(window.frame, window.screen.bounds) : YES;
   // We are catching here two situations for multitasking view:
   // a) The app is in Split View and the container gets resized -> !isRunningInFullScreen
   // b) The app changes to/from fullscreen example: App runs in slide over mode and goes into fullscreen->

packages/react-native/React/React-RCTFabric.podspec

@@ -91,9 +91,9 @@ Pod::Spec.new do |s|
   add_dependency(s, "React-RCTAnimation", :framework_name => 'RCTAnimation')
   add_dependency(s, "React-jsinspector", :framework_name => 'jsinspector_modern')
   add_dependency(s, "React-jsinspectorcdp", :framework_name => 'jsinspector_moderncdp')
-  add_dependency(s, "React-jsinspectornetwork", :framework_name => 'jsinspector_modernnetwork')
   add_dependency(s, "React-jsinspectortracing", :framework_name => 'jsinspector_moderntracing')
   add_dependency(s, "React-performancecdpmetrics", :framework_name => 'React_performancecdpmetrics')
+  add_dependency(s, "React-networking", :framework_name => 'React_networking')
   add_dependency(s, "React-renderercss")
   add_dependency(s, "React-RCTFBReactNativeSpec")
 

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

@@ -2354,12 +2354,14 @@ public class com/facebook/react/fabric/mounting/SurfaceMountingManager {
 	public fun sendAccessibilityEvent (II)V
 	public fun setJSResponder (IIZ)V
 	public fun stopSurface ()V
+	public fun storeSynchronousMountPropsOverride (ILcom/facebook/react/bridge/ReadableMap;)V
 	public fun sweepActiveTouchForTag (I)V
 	public fun updateEventEmitter (ILcom/facebook/react/fabric/events/EventEmitterWrapper;)V
 	public fun updateLayout (IIIIIIII)V
 	public fun updateOverflowInset (IIIII)V
 	public fun updatePadding (IIIII)V
 	public fun updateProps (ILcom/facebook/react/bridge/ReadableMap;)V
+	public fun updatePropsSynchronously (ILcom/facebook/react/bridge/ReadableMap;)V
 	public fun updateState (ILcom/facebook/react/uimanager/StateWrapper;)V
 }
 

packages/react-native/ReactAndroid/hermes-engine/build.gradle.kts

@@ -88,7 +88,7 @@ val hermesVersionProvider: Provider<String> =
       val hermesVersionFile =
           File(
               reactNativeRootDir,
-              if (hermesV1Enabled) "sdks/.hermesv1version" else "\"sdks/.hermesversion\"",
+              if (hermesV1Enabled) "sdks/.hermesv1version" else "sdks/.hermesversion",
           )
 
       if (hermesVersionFile.exists()) {

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

@@ -83,6 +83,6 @@ internal class BridgelessDevSupportManager(
   }
 
   fun tracingState(): TracingState {
-    return TracingState.DISABLED
+    return TracingState.ENABLEDINCDPMODE
   }
 }

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

@@ -68,6 +68,7 @@ import com.facebook.react.devsupport.interfaces.StackFrame
 import com.facebook.react.devsupport.interfaces.TracingState
 import com.facebook.react.devsupport.interfaces.TracingStateProvider
 import com.facebook.react.devsupport.perfmonitor.PerfMonitorDevHelper
+import com.facebook.react.devsupport.perfmonitor.PerfMonitorOverlayManager
 import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
 import com.facebook.react.internal.featureflags.ReactNativeNewArchitectureFeatureFlags
 import com.facebook.react.modules.core.RCTNativeAppEventEmitter
@@ -77,6 +78,7 @@ import java.io.File
 import java.net.MalformedURLException
 import java.net.URL
 import java.util.Locale
+import javax.inject.Provider
 
 public abstract class DevSupportManagerBase(
     protected val applicationContext: Context,
@@ -182,7 +184,7 @@ public abstract class DevSupportManagerBase(
           null
         }
 
-  private var perfMonitorOverlayManager: PerfMonitorOverlayViewManager? = null
+  private var perfMonitorOverlayManager: PerfMonitorOverlayManager? = null
   private var tracingStateProvider: TracingStateProvider? = null
 
   init {
@@ -215,19 +217,19 @@ public abstract class DevSupportManagerBase(
     if (
         ReactNativeNewArchitectureFeatureFlags.enableBridgelessArchitecture() &&
             ReactNativeFeatureFlags.perfMonitorV2Enabled() &&
-            reactInstanceDevHelper is PerfMonitorDevHelper &&
-            perfMonitorOverlayManager == null
+            reactInstanceDevHelper is PerfMonitorDevHelper
     ) {
       perfMonitorOverlayManager =
-          PerfMonitorOverlayViewManager(
-              Supplier {
+          PerfMonitorOverlayManager(
+              reactInstanceDevHelper,
+              Provider {
                 val context = reactInstanceDevHelper.currentActivity
                 if (context == null || context.isFinishing) {
-                  return@Supplier null
+                  return@Provider null
                 }
                 context
               },
-              reactInstanceDevHelper.inspectorTarget,
+              { openDebugger(DebuggerFrontendPanelName.PERFORMANCE.toString()) },
           )
     }
   }
@@ -548,10 +550,11 @@ public abstract class DevSupportManagerBase(
   override fun onNewReactContextCreated(reactContext: ReactContext) {
     resetCurrentContext(reactContext)
 
-    if (perfMonitorOverlayManager != null && reactInstanceDevHelper is PerfMonitorDevHelper) {
+    if (reactInstanceDevHelper is PerfMonitorDevHelper) {
       perfMonitorOverlayManager?.let { manager ->
         reactInstanceDevHelper.inspectorTarget?.addPerfMonitorListener(manager)
       }
+      perfMonitorOverlayManager?.enable()
     }
   }
 
@@ -882,6 +885,7 @@ public abstract class DevSupportManagerBase(
 
             override fun onPackagerDisconnected() {
               isPackagerConnected = false
+              perfMonitorOverlayManager?.disable()
             }
 
             override fun onPackagerReloadCommand() {

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

@@ -1,20 +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.devsupport.interfaces
-
-/** [Experimental] Interface to manage the V2 Perf Monitor overlay. */
-internal interface PerfMonitorOverlayManager {
-  /** Enable the Perf Monitor overlay. Will be shown when updates are received. */
-  public fun enable()
-
-  /** Disable the Perf Monitor overlay. Will remain hidden when updates are received. */
-  public fun disable()
-
-  /** Reset the Perf Monitor overlay, e.g. after a reload. */
-  public fun reset()
-}

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

@@ -7,11 +7,16 @@
 
 package com.facebook.react.devsupport.perfmonitor
 
+import com.facebook.react.devsupport.interfaces.TracingState
+
 /**
  * [Experimental] Interface implemented by [com.facebook.react.runtime.ReactHostInspectorTarget]
  * exposing actions for the V2 Perf Monitor.
  */
 internal interface PerfMonitorInspectorTargetBinding {
+  /** Get the current CDP or background performance tracing state. */
+  public fun getTracingState(): TracingState
+
   /** Attempt to pause the current background performance trace, and open in DevTools. */
   public fun pauseAndAnalyzeBackgroundTrace()
 

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

@@ -0,0 +1,86 @@
+/*
+ * 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.devsupport.perfmonitor
+
+import android.content.Context
+import com.facebook.react.bridge.UiThreadUtil
+import com.facebook.react.devsupport.interfaces.TracingState
+import javax.inject.Provider
+
+internal class PerfMonitorOverlayManager(
+    private val devHelper: PerfMonitorDevHelper,
+    private val contextProvider: Provider<Context?>,
+    private val onRequestOpenDevTools: () -> Unit,
+) : PerfMonitorUpdateListener {
+  private var enabled: Boolean = false
+  private var initialized: Boolean = false
+  private var view: PerfMonitorOverlayView? = null
+  private var tracingState: TracingState = TracingState.ENABLEDINCDPMODE
+
+  private fun init() {
+    if (initialized || !enabled) {
+      return
+    }
+
+    UiThreadUtil.runOnUiThread {
+      val context = contextProvider.get() ?: return@runOnUiThread
+      view = PerfMonitorOverlayView(context, ::handleRecordingButtonPress)
+
+      // Start background tracing
+      devHelper.inspectorTarget?.resumeBackgroundTrace()
+
+      view?.show()
+      initialized = true
+    }
+  }
+
+  /** Enable the Perf Monitor overlay. Will be shown when updates are received. */
+  fun enable() {
+    enabled = true
+    init()
+    UiThreadUtil.runOnUiThread { view?.show() }
+  }
+
+  /** Disable the Perf Monitor overlay. Will remain hidden when updates are received. */
+  fun disable() {
+    UiThreadUtil.runOnUiThread { view?.hide() }
+    enabled = false
+  }
+
+  /** Reset the Perf Monitor overlay, e.g. after a reload. */
+  fun reset() {
+    UiThreadUtil.runOnUiThread { view?.resetState() }
+
+    // Update with current recording state
+    onRecordingStateChanged(
+        devHelper.inspectorTarget?.getTracingState() ?: TracingState.ENABLEDINCDPMODE
+    )
+  }
+
+  override fun onNewFocusedEvent(data: PerfMonitorUpdateListener.LongTaskEventData) {
+    view?.updateFocusedEvent(data)
+  }
+
+  override fun onRecordingStateChanged(state: TracingState) {
+    tracingState = state
+    view?.updateRecordingState(state)
+  }
+
+  private fun handleRecordingButtonPress() {
+    when (tracingState) {
+      TracingState.ENABLEDINBACKGROUNDMODE -> {
+        devHelper.inspectorTarget?.pauseAndAnalyzeBackgroundTrace()
+        onRequestOpenDevTools()
+      }
+      TracingState.DISABLED -> {
+        devHelper.inspectorTarget?.resumeBackgroundTrace()
+      }
+      TracingState.ENABLEDINCDPMODE -> Unit
+    }
+  }
+}

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

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-package com.facebook.react.devsupport
+package com.facebook.react.devsupport.perfmonitor
 
 import android.app.Dialog
 import android.content.Context
@@ -20,107 +20,110 @@ import android.view.Window
 import android.view.WindowManager
 import android.widget.LinearLayout
 import android.widget.TextView
-import androidx.core.util.Supplier
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
 import com.facebook.react.R
-import com.facebook.react.bridge.UiThreadUtil
-import com.facebook.react.devsupport.interfaces.PerfMonitorOverlayManager
 import com.facebook.react.devsupport.interfaces.TracingState
-import com.facebook.react.devsupport.perfmonitor.PerfMonitorInspectorTargetBinding
-import com.facebook.react.devsupport.perfmonitor.PerfMonitorUpdateListener
 import com.facebook.react.uimanager.DisplayMetricsHolder
 import com.facebook.react.uimanager.PixelUtil
 import java.util.Locale
 
-internal class PerfMonitorOverlayViewManager(
-    private val contextSupplier: Supplier<Context?>,
-    private val inspectorTarget: PerfMonitorInspectorTargetBinding?,
-) : PerfMonitorOverlayManager, PerfMonitorUpdateListener {
-  private var initialized: Boolean = false
-  private var enabled: Boolean = false
-  private var hasInteractionData: Boolean = false
-  private var interactionDialog: Dialog? = null
-  private var buttonDialog: Dialog? = null
-  private var durationLabel: TextView? = null
+internal class PerfMonitorOverlayView(
+    private val context: Context,
+    private val onButtonPress: () -> Unit,
+) {
+  private var hidden: Boolean = true
+  private var hasEventData: Boolean = false
+  private val metricsDialog: Dialog
+  private val toolbarDialog: Dialog
+  private val tooltipDialog: Dialog
+  private lateinit var buttonLabel: TextView
+  private lateinit var recordingStateLabel: TextView
+  private lateinit var durationLabel: TextView
+  private lateinit var tooltipLabel: TextView
   private var ttl: Int = 0
   private var hideAfterTimeoutHandler: Handler? = null
 
-  override fun enable() {
-    UiThreadUtil.runOnUiThread {
-      enabled = true
-      if (hasInteractionData) {
-        showOverlay()
-      }
-    }
-  }
-
-  override fun disable() {
-    UiThreadUtil.runOnUiThread {
-      enabled = false
-      hideOverlay()
-    }
-  }
-
-  override fun reset() {
-    UiThreadUtil.runOnUiThread {
-      hasInteractionData = false
-      hideOverlay()
-    }
-  }
-
-  override fun onRecordingStateChanged(state: TracingState) {
-    // recordingState = state
-    // view?.updateRecordingState(state)
-  }
-
-  override fun onNewFocusedEvent(data: PerfMonitorUpdateListener.LongTaskEventData) {
-    UiThreadUtil.runOnUiThread {
-      ensureInitialized()
-      durationLabel?.text = String.format(Locale.US, "%d ms", data.durationMs)
-      durationLabel?.setTextColor(getDurationHighlightColor(data.responsivenessScore))
-      hasInteractionData = true
-      ttl = data.ttl
-
-      hideAfterTimeoutHandler?.removeCallbacksAndMessages(null)
-
-      if (enabled) {
-        showOverlay()
-
-        // Schedule hiding overlay after ttl milliseconds
-        if (ttl > 0) {
-          if (hideAfterTimeoutHandler == null) {
-            hideAfterTimeoutHandler = Handler(Looper.getMainLooper())
-          }
-          hideAfterTimeoutHandler?.postDelayed({ hideOverlay() }, ttl.toLong())
-        }
-      }
-    }
-  }
-
-  private fun ensureInitialized() {
-    if (initialized) {
-      return
-    }
-    val context = contextSupplier.get() ?: return
+  init {
     DisplayMetricsHolder.initDisplayMetricsIfNotInitialized(context)
-    createDialog(context)
-    createButton(context)
-    initialized = true
+    tooltipDialog = createTooltipDialog()
+    metricsDialog = createMetricsDialog()
+    toolbarDialog = createToolbarDialog()
   }
 
-  private fun showOverlay() {
-    interactionDialog?.show()
-    buttonDialog?.show()
+  fun show() {
+    toolbarDialog.show()
+    tooltipDialog.show()
+    if (hasEventData) {
+      toolbarDialog.window?.decorView?.post { updateMetricsDialogPosition() }
+      metricsDialog.show()
+    }
+    hidden = false
   }
 
-  private fun hideOverlay() {
-    interactionDialog?.hide()
-    buttonDialog?.hide()
+  fun hide() {
+    metricsDialog.hide()
+    toolbarDialog.hide()
+    tooltipDialog.hide()
+    hidden = true
   }
 
-  private fun createDialog(context: Context) {
-    val containerLayout = createInnerLayout(context)
+  fun resetState() {
+    hasEventData = false
+    metricsDialog.hide()
+  }
+
+  fun updateFocusedEvent(data: PerfMonitorUpdateListener.LongTaskEventData) {
+    durationLabel.text = String.format(Locale.US, "%d ms", data.durationMs)
+    durationLabel.setTextColor(getDurationHighlightColor(data.responsivenessScore))
+    hasEventData = true
+    ttl = data.ttl
+
+    hideAfterTimeoutHandler?.removeCallbacksAndMessages(null)
+
+    if (!hidden) {
+      metricsDialog.show()
+
+      // Schedule hiding metrics overlay after ttl milliseconds
+      if (ttl > 0) {
+        if (hideAfterTimeoutHandler == null) {
+          hideAfterTimeoutHandler = Handler(Looper.getMainLooper())
+        }
+        hideAfterTimeoutHandler?.postDelayed({ metricsDialog.hide() }, ttl.toLong())
+      }
+    }
+  }
+
+  fun updateRecordingState(state: TracingState) {
+    recordingStateLabel.text =
+        when (state) {
+          TracingState.ENABLEDINBACKGROUNDMODE -> "Profiling: ON"
+          TracingState.DISABLED -> "Profiling: OFF"
+          TracingState.ENABLEDINCDPMODE -> "Profiling: DISABLED"
+        }
+    buttonLabel.text =
+        when (state) {
+          TracingState.ENABLEDINBACKGROUNDMODE -> "Open ↗️"
+          TracingState.DISABLED -> "Start"
+          TracingState.ENABLEDINCDPMODE -> ""
+        }
+    tooltipLabel.text =
+        when (state) {
+          TracingState.ENABLEDINBACKGROUNDMODE -> "Dev Menu > Finish performance trace"
+          TracingState.DISABLED -> "Dev Menu > Start performance trace"
+          TracingState.ENABLEDINCDPMODE -> ""
+        }
+    if (state == TracingState.ENABLEDINCDPMODE) {
+      tooltipDialog.hide()
+    } else {
+      tooltipDialog.show()
+    }
+
+    toolbarDialog.window?.decorView?.post { updateMetricsDialogPosition() }
+  }
+
+  private fun createMetricsDialog(): Dialog {
+    val containerLayout = createInnerLayout()
     val longTaskLabel =
         TextView(context).apply {
           textSize = TEXT_SIZE_PRIMARY
@@ -138,7 +141,7 @@ internal class PerfMonitorOverlayViewManager(
     containerLayout.addView(durationLabel)
 
     val dialog =
-        createAnchoredDialog(context, dpToPx(140f), dpToPx(16f)).apply {
+        createAnchoredDialog(getMetricsDialogOffsetX(), dpToPx(16f)).apply {
           setContentView(containerLayout)
         }
     dialog.window?.apply {
@@ -151,30 +154,25 @@ internal class PerfMonitorOverlayViewManager(
           }
     }
 
-    this.interactionDialog = dialog
+    return dialog
   }
 
-  fun updateRecordingState(state: TracingState) {}
-
-  private fun createButton(context: Context) {
-    val buttonInner = createInnerLayout(context)
-    buttonInner.addView(
+  private fun createToolbarDialog(): Dialog {
+    val buttonInner = createInnerLayout()
+    recordingStateLabel =
         TextView(context).apply {
-          text = "Analyze"
           textSize = TEXT_SIZE_PRIMARY
           setTextColor(Color.WHITE)
           typeface = TYPEFACE_BOLD
         }
-    )
-    buttonInner.addView(
+    buttonInner.addView(recordingStateLabel)
+    buttonLabel =
         TextView(context).apply {
-          text = "cmd + A"
-          textSize = TEXT_SIZE_ACCESSORY
-          setTextColor(Color.WHITE)
-          alpha = 0.7f
+          textSize = TEXT_SIZE_PRIMARY
+          setTextColor(COLOR_TEXT_BLUE)
           typeface = TYPEFACE_BOLD
         }
-    )
+    buttonInner.addView(buttonLabel)
     val buttonView =
         LinearLayout(context).apply {
           orientation = LinearLayout.VERTICAL
@@ -185,19 +183,43 @@ internal class PerfMonitorOverlayViewManager(
               dpToPx(8f).toInt(),
           )
           addView(buttonInner)
-          setOnClickListener { inspectorTarget?.pauseAndAnalyzeBackgroundTrace() }
+          setOnClickListener { onButtonPress() }
         }
-    val dialog =
-        createAnchoredDialog(context, dpToPx(0f), dpToPx(0f)).apply { setContentView(buttonView) }
+
+    val dialog = createAnchoredDialog(dpToPx(0f), dpToPx(0f)).apply { setContentView(buttonView) }
     dialog.window?.apply {
       attributes =
           attributes?.apply { flags = flags or WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE }
     }
 
-    this.buttonDialog = dialog
+    return dialog
   }
 
-  private fun createAnchoredDialog(context: Context, offsetX: Float, offsetY: Float): Dialog {
+  private fun createTooltipDialog(): Dialog {
+    val containerLayout = createInnerLayout()
+    tooltipLabel =
+        TextView(context).apply {
+          textSize = TEXT_SIZE_ACCESSORY
+          setTextColor(Color.WHITE)
+        }
+    containerLayout.addView(tooltipLabel)
+
+    val dialog =
+        createAnchoredDialog(dpToPx(16f), dpToPx(52f)).apply { setContentView(containerLayout) }
+    dialog.window?.apply {
+      attributes =
+          attributes?.apply {
+            flags =
+                flags or
+                    WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE or
+                    WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
+          }
+    }
+
+    return dialog
+  }
+
+  private fun createAnchoredDialog(offsetX: Float, offsetY: Float): Dialog {
     val dialog =
         Dialog(context, R.style.NoAnimationDialog).apply {
           requestWindowFeature(Window.FEATURE_NO_TITLE)
@@ -228,12 +250,12 @@ internal class PerfMonitorOverlayViewManager(
     return dialog
   }
 
-  private fun createInnerLayout(context: Context): LinearLayout {
+  private fun createInnerLayout(): LinearLayout {
     return LinearLayout(context).apply {
       orientation = LinearLayout.HORIZONTAL
       gravity = Gravity.CENTER_VERTICAL
       val paddingHorizontal = dpToPx(14f).toInt()
-      val paddingVertical = dpToPx(8f).toInt()
+      val paddingVertical = dpToPx(7f).toInt()
       setPadding(paddingHorizontal, paddingVertical, paddingHorizontal, paddingVertical)
       layoutParams =
           LinearLayout.LayoutParams(
@@ -256,10 +278,21 @@ internal class PerfMonitorOverlayViewManager(
     }
   }
 
+  private fun getMetricsDialogOffsetX(): Float {
+    val toolbarWidth = toolbarDialog?.window?.decorView?.width ?: 0
+    return toolbarWidth.toFloat()
+  }
+
+  private fun updateMetricsDialogPosition() {
+    metricsDialog?.window?.apply {
+      attributes = attributes?.apply { x = getMetricsDialogOffsetX().toInt() }
+    }
+  }
+
   private fun getDurationHighlightColor(responsivenessScore: Int): Int {
     return when (responsivenessScore) {
-      3 -> COLOR_TEXT_RED
-      2 -> COLOR_TEXT_YELLOW
+      2 -> COLOR_TEXT_RED
+      1 -> COLOR_TEXT_YELLOW
       else -> COLOR_TEXT_GREEN
     }
   }
@@ -270,6 +303,7 @@ internal class PerfMonitorOverlayViewManager(
     private val COLOR_TEXT_GREEN = Color.parseColor("#4AEB2F")
     private val COLOR_TEXT_YELLOW = Color.parseColor("#FFAA00")
     private val COLOR_TEXT_RED = Color.parseColor("#FF0000")
+    private val COLOR_TEXT_BLUE = Color.parseColor("#00B0FF")
     private val COLOR_OVERLAY_BORDER = Color.parseColor("#6C6C6C")
     private val TEXT_SIZE_PRIMARY = 13f
     private val TEXT_SIZE_ACCESSORY = 9f

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java

@@ -791,7 +791,8 @@ public class FabricUIManager
           @Override
           public void execute(MountingManager mountingManager) {
             try {
-              mountingManager.updateProps(reactTag, props);
+              mountingManager.storeSynchronousMountPropsOverride(reactTag, props);
+              mountingManager.updatePropsSynchronously(reactTag, props);
             } catch (Exception ex) {
               // TODO T42943890: Fix animations in Fabric and remove this try/catch?
               // There might always be race conditions between surface teardown and

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/MountingManager.kt

@@ -265,13 +265,23 @@ internal class MountingManager(
   }
 
   @UiThread
-  fun updateProps(reactTag: Int, props: ReadableMap?) {
+  fun storeSynchronousMountPropsOverride(reactTag: Int, props: ReadableMap?) {
     assertOnUiThread()
     if (props == null) {
       return
     }
 
-    getSurfaceManagerForViewEnforced(reactTag).updateProps(reactTag, props)
+    getSurfaceManagerForViewEnforced(reactTag).storeSynchronousMountPropsOverride(reactTag, props)
+  }
+
+  @UiThread
+  fun updatePropsSynchronously(reactTag: Int, props: ReadableMap?) {
+    assertOnUiThread()
+    if (props == null) {
+      return
+    }
+
+    getSurfaceManagerForViewEnforced(reactTag).updatePropsSynchronously(reactTag, props)
   }
 
   /**

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/SurfaceMountingManager.java

@@ -27,10 +27,14 @@ import com.facebook.react.bridge.ReactNoCrashSoftException;
 import com.facebook.react.bridge.ReactSoftExceptionLogger;
 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.bridge.SoftAssertions;
 import com.facebook.react.bridge.UiThreadUtil;
+import com.facebook.react.bridge.WritableArray;
 import com.facebook.react.bridge.WritableMap;
+import com.facebook.react.bridge.WritableNativeArray;
+import com.facebook.react.bridge.WritableNativeMap;
 import com.facebook.react.common.annotations.UnstableReactNativeAPI;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.common.mapbuffer.MapBuffer;
@@ -53,7 +57,10 @@ import com.facebook.react.uimanager.ViewManagerRegistry;
 import com.facebook.react.uimanager.events.EventCategoryDef;
 import com.facebook.systrace.Systrace;
 import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.Map;
 import java.util.Queue;
@@ -96,6 +103,11 @@ public class SurfaceMountingManager {
   // This is null *until* StopSurface is called.
   private SparseArrayCompat<Object> mTagSetForStoppedSurface;
 
+  // This is to make sure direct manipulation result will not be overridden by React update.
+  @ThreadConfined(UI)
+  private final SparseArrayCompat<Map<String, Object>> mTagToSynchronousMountProps =
+      new SparseArrayCompat<>();
+
   private final int mSurfaceId;
 
   public SurfaceMountingManager(
@@ -682,13 +694,110 @@ public class SurfaceMountingManager {
     }
   }
 
+  private static void overridePropsReadableMap(
+      Map<String, Object> patchMap, WritableMap outputReadableMap) {
+    for (Map.Entry<String, Object> entry : patchMap.entrySet()) {
+      String propKey = entry.getKey();
+      if (outputReadableMap.hasKey(propKey)) {
+        Object propValue = entry.getValue();
+        if (propKey.equals("transform")) {
+          assert (outputReadableMap.getType(propKey) == ReadableType.Array
+              && propValue instanceof ArrayList);
+          WritableArray array = new WritableNativeArray();
+          for (Object item : (ArrayList<?>) propValue) {
+            if (item instanceof HashMap) {
+              WritableNativeMap itemMap = new WritableNativeMap();
+              for (Map.Entry<String, Object> itemEntry :
+                  ((HashMap<String, Object>) item).entrySet()) {
+                if (itemEntry.getValue() instanceof String) {
+                  itemMap.putString(itemEntry.getKey(), (String) itemEntry.getValue());
+                } else if (itemEntry.getValue() instanceof Number) {
+                  itemMap.putDouble(
+                      itemEntry.getKey(), ((Number) itemEntry.getValue()).doubleValue());
+                }
+              }
+              array.pushMap(itemMap);
+            }
+          }
+          outputReadableMap.putArray(propKey, array);
+        } else if (propKey.equals("opacity")) {
+          assert (outputReadableMap.getType(propKey) == ReadableType.Number
+              && propValue instanceof Number);
+          outputReadableMap.putDouble(propKey, ((Number) propValue).doubleValue());
+        }
+      }
+    }
+  }
+
+  private static Map<String, Object> getHashMapFromPropsReadableMap(ReadableMap readableMap) {
+    HashMap<String, Object> outputMap = new HashMap<>();
+
+    Iterator<Map.Entry<String, Object>> iter = readableMap.getEntryIterator();
+    while (iter.hasNext()) {
+      Map.Entry<String, Object> entry = iter.next();
+      String propKey = entry.getKey();
+      Object propValue = entry.getValue();
+      if (propKey.equals("transform") && propValue instanceof ReadableArray) {
+        ArrayList<HashMap<String, Object>> arrayList = new ArrayList<>();
+        for (int i = 0; i < ((ReadableArray) propValue).size(); i++) {
+          ReadableMap map = ((ReadableArray) propValue).getMap(i);
+          if (map != null) {
+            arrayList.add(map.toHashMap());
+          }
+        }
+        outputMap.put(propKey, arrayList);
+      } else if (propKey.equals("opacity") && propValue instanceof Number) {
+        outputMap.put(propKey, ((Number) propValue).doubleValue());
+      }
+    }
+
+    return outputMap;
+  }
+
+  public void storeSynchronousMountPropsOverride(int reactTag, ReadableMap props) {
+    if (ReactNativeFeatureFlags.overrideBySynchronousMountPropsAtMountingAndroid()) {
+      Map<String, Object> propsMap = getHashMapFromPropsReadableMap(props);
+      if (mTagToSynchronousMountProps.containsKey(reactTag)) {
+        Map<String, Object> mergedPropsMap =
+            Assertions.assertNotNull(mTagToSynchronousMountProps.get(reactTag));
+        mergedPropsMap.putAll(propsMap);
+        mTagToSynchronousMountProps.put(reactTag, mergedPropsMap);
+      } else {
+        mTagToSynchronousMountProps.put(reactTag, propsMap);
+      }
+    }
+  }
+
+  public void updatePropsSynchronously(int reactTag, ReadableMap props) {
+    updateProps(reactTag, props, true);
+  }
+
   public void updateProps(int reactTag, ReadableMap props) {
+    updateProps(reactTag, props, false);
+  }
+
+  @UiThread
+  private void updateProps(
+      int reactTag, ReadableMap props, Boolean shouldSkipSynchronousMountPropsOverride) {
     if (isStopped()) {
       return;
     }
 
     ViewState viewState = getViewState(reactTag);
-    viewState.mCurrentProps = new ReactStylesDiffMap(props);
+
+    if (ReactNativeFeatureFlags.overrideBySynchronousMountPropsAtMountingAndroid()
+        && !shouldSkipSynchronousMountPropsOverride
+        && mTagToSynchronousMountProps.containsKey(reactTag)) {
+      WritableMap modifiedProps = new WritableNativeMap();
+      modifiedProps.merge(props);
+      Map<String, Object> directPropsMap =
+          Assertions.assertNotNull(mTagToSynchronousMountProps.get(reactTag));
+      overridePropsReadableMap(directPropsMap, modifiedProps);
+      viewState.mCurrentProps = new ReactStylesDiffMap(modifiedProps);
+    } else {
+      viewState.mCurrentProps = new ReactStylesDiffMap(props);
+    }
+
     View view = viewState.mView;
 
     if (view == null) {
@@ -1057,6 +1166,11 @@ public class SurfaceMountingManager {
       return;
     }
 
+    if (ReactNativeFeatureFlags.overrideBySynchronousMountPropsAtMountingAndroid()
+        && mTagToSynchronousMountProps.containsKey(reactTag)) {
+      mTagToSynchronousMountProps.remove(reactTag);
+    }
+
     ViewState viewState = getNullableViewState(reactTag);
 
     if (viewState == 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<<92a6edded037a504fc1c2c8ae88deae1>>
+ * @generated SignedSource<<8300eb10fb4906468cd5f04afd8e16cd>>
  */
 
 /**
@@ -300,6 +300,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableVirtualViewWindowFocusDetection(): Boolean = accessor.enableVirtualViewWindowFocusDetection()
 
+  /**
+   * Enable Web Performance APIs (Performance Timeline, User Timings, etc.) by default.
+   */
+  @JvmStatic
+  public fun enableWebPerformanceAPIsByDefault(): Boolean = accessor.enableWebPerformanceAPIsByDefault()
+
   /**
    * Uses the default event priority instead of the discreet event priority by default when dispatching events from Fabric to React.
    */
@@ -324,6 +330,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun hideOffscreenVirtualViewsOnIOS(): Boolean = accessor.hideOffscreenVirtualViewsOnIOS()
 
+  /**
+   * Override props at mounting with synchronously mounted (i.e. direct manipulation) props from Native Animated.
+   */
+  @JvmStatic
+  public fun overrideBySynchronousMountPropsAtMountingAndroid(): Boolean = accessor.overrideBySynchronousMountPropsAtMountingAndroid()
+
   /**
    * Enable the V2 in-app Performance Monitor. This flag is global and should not be changed across React Host lifetimes.
    */

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<<ebbc6602fc8e3fb4c510bbd47361a7f0>>
+ * @generated SignedSource<<ea5133af611c4d1e7e70155a3a74492d>>
  */
 
 /**
@@ -65,10 +65,12 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var enableVirtualViewDebugFeaturesCache: Boolean? = null
   private var enableVirtualViewRenderStateCache: Boolean? = null
   private var enableVirtualViewWindowFocusDetectionCache: Boolean? = null
+  private var enableWebPerformanceAPIsByDefaultCache: Boolean? = null
   private var fixMappingOfEventPrioritiesBetweenFabricAndReactCache: Boolean? = null
   private var fuseboxEnabledReleaseCache: Boolean? = null
   private var fuseboxNetworkInspectionEnabledCache: Boolean? = null
   private var hideOffscreenVirtualViewsOnIOSCache: Boolean? = null
+  private var overrideBySynchronousMountPropsAtMountingAndroidCache: Boolean? = null
   private var perfMonitorV2EnabledCache: Boolean? = null
   private var preparedTextCacheSizeCache: Double? = null
   private var preventShadowTreeCommitExhaustionCache: Boolean? = null
@@ -495,6 +497,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun enableWebPerformanceAPIsByDefault(): Boolean {
+    var cached = enableWebPerformanceAPIsByDefaultCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableWebPerformanceAPIsByDefault()
+      enableWebPerformanceAPIsByDefaultCache = cached
+    }
+    return cached
+  }
+
   override fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean {
     var cached = fixMappingOfEventPrioritiesBetweenFabricAndReactCache
     if (cached == null) {
@@ -531,6 +542,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun overrideBySynchronousMountPropsAtMountingAndroid(): Boolean {
+    var cached = overrideBySynchronousMountPropsAtMountingAndroidCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.overrideBySynchronousMountPropsAtMountingAndroid()
+      overrideBySynchronousMountPropsAtMountingAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun perfMonitorV2Enabled(): Boolean {
     var cached = perfMonitorV2EnabledCache
     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<<4410628511f112f3eef22434a05fa757>>
+ * @generated SignedSource<<cf5b9f099846d4f954304905f77ebe17>>
  */
 
 /**
@@ -118,6 +118,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableVirtualViewWindowFocusDetection(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun enableWebPerformanceAPIsByDefault(): Boolean
+
   @DoNotStrip @JvmStatic public external fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean
 
   @DoNotStrip @JvmStatic public external fun fuseboxEnabledRelease(): Boolean
@@ -126,6 +128,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun hideOffscreenVirtualViewsOnIOS(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun overrideBySynchronousMountPropsAtMountingAndroid(): Boolean
+
   @DoNotStrip @JvmStatic public external fun perfMonitorV2Enabled(): Boolean
 
   @DoNotStrip @JvmStatic public external fun preparedTextCacheSize(): Double

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<<411732d441bacbef37c3474b9041202c>>
+ * @generated SignedSource<<305496047314dc97352a6e0dad0bba54>>
  */
 
 /**
@@ -113,6 +113,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableVirtualViewWindowFocusDetection(): Boolean = false
 
+  override fun enableWebPerformanceAPIsByDefault(): Boolean = false
+
   override fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean = false
 
   override fun fuseboxEnabledRelease(): Boolean = false
@@ -121,6 +123,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun hideOffscreenVirtualViewsOnIOS(): Boolean = false
 
+  override fun overrideBySynchronousMountPropsAtMountingAndroid(): Boolean = false
+
   override fun perfMonitorV2Enabled(): Boolean = false
 
   override fun preparedTextCacheSize(): Double = 200.0

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<<2f65e0e9066a8c2c35c44ea7c73dbedc>>
+ * @generated SignedSource<<f3798eada96337cf98715fa580823b30>>
  */
 
 /**
@@ -69,10 +69,12 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var enableVirtualViewDebugFeaturesCache: Boolean? = null
   private var enableVirtualViewRenderStateCache: Boolean? = null
   private var enableVirtualViewWindowFocusDetectionCache: Boolean? = null
+  private var enableWebPerformanceAPIsByDefaultCache: Boolean? = null
   private var fixMappingOfEventPrioritiesBetweenFabricAndReactCache: Boolean? = null
   private var fuseboxEnabledReleaseCache: Boolean? = null
   private var fuseboxNetworkInspectionEnabledCache: Boolean? = null
   private var hideOffscreenVirtualViewsOnIOSCache: Boolean? = null
+  private var overrideBySynchronousMountPropsAtMountingAndroidCache: Boolean? = null
   private var perfMonitorV2EnabledCache: Boolean? = null
   private var preparedTextCacheSizeCache: Double? = null
   private var preventShadowTreeCommitExhaustionCache: Boolean? = null
@@ -544,6 +546,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun enableWebPerformanceAPIsByDefault(): Boolean {
+    var cached = enableWebPerformanceAPIsByDefaultCache
+    if (cached == null) {
+      cached = currentProvider.enableWebPerformanceAPIsByDefault()
+      accessedFeatureFlags.add("enableWebPerformanceAPIsByDefault")
+      enableWebPerformanceAPIsByDefaultCache = cached
+    }
+    return cached
+  }
+
   override fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean {
     var cached = fixMappingOfEventPrioritiesBetweenFabricAndReactCache
     if (cached == null) {
@@ -584,6 +596,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun overrideBySynchronousMountPropsAtMountingAndroid(): Boolean {
+    var cached = overrideBySynchronousMountPropsAtMountingAndroidCache
+    if (cached == null) {
+      cached = currentProvider.overrideBySynchronousMountPropsAtMountingAndroid()
+      accessedFeatureFlags.add("overrideBySynchronousMountPropsAtMountingAndroid")
+      overrideBySynchronousMountPropsAtMountingAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun perfMonitorV2Enabled(): Boolean {
     var cached = perfMonitorV2EnabledCache
     if (cached == null) {

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<<e97601660cfd4f614ac934ba20ca4635>>
+ * @generated SignedSource<<c36e7ac588eb68660f000e7792ec2384>>
  */
 
 /**
@@ -113,6 +113,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableVirtualViewWindowFocusDetection(): Boolean
 
+  @DoNotStrip public fun enableWebPerformanceAPIsByDefault(): Boolean
+
   @DoNotStrip public fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean
 
   @DoNotStrip public fun fuseboxEnabledRelease(): Boolean
@@ -121,6 +123,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun hideOffscreenVirtualViewsOnIOS(): Boolean
 
+  @DoNotStrip public fun overrideBySynchronousMountPropsAtMountingAndroid(): Boolean
+
   @DoNotStrip public fun perfMonitorV2Enabled(): Boolean
 
   @DoNotStrip public fun preparedTextCacheSize(): Double

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/core/JavaTimerManager.kt

@@ -310,8 +310,8 @@ public open class JavaTimerManager(
           }
         }
       }
-      timersToCall?.let {
-        javaScriptTimerExecutor.callTimers(it)
+      timersToCall?.let { timers ->
+        javaScriptTimerExecutor.callTimers(timers)
         timersToCall = null
       }
       reactChoreographer.postFrameCallback(ReactChoreographer.CallbackType.TIMERS_EVENTS, this)

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

@@ -81,6 +81,6 @@ internal class ReactHostImplDevHelper(private val delegate: ReactHostImpl) :
       delegate.loadBundle(bundleLoader)
 
   override fun getTracingState(): TracingState {
-    return delegate.reactHostInspectorTarget?.tracingState() ?: TracingState.DISABLED
+    return delegate.reactHostInspectorTarget?.getTracingState() ?: TracingState.ENABLEDINCDPMODE
   }
 }

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

@@ -43,7 +43,7 @@ internal class ReactHostInspectorTarget(reactHostImpl: ReactHostImpl) :
 
   external fun tracingStateAsInt(): Int
 
-  fun tracingState(): TracingState {
+  override fun getTracingState(): TracingState {
     return TracingState.entries[tracingStateAsInt()]
   }
 

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

@@ -124,6 +124,8 @@ add_react_common_subdir(react/nativemodule/dom)
 add_react_common_subdir(react/nativemodule/featureflags)
 add_react_common_subdir(react/nativemodule/microtasks)
 add_react_common_subdir(react/nativemodule/idlecallbacks)
+add_react_common_subdir(react/nativemodule/webperformance)
+add_react_common_subdir(react/networking)
 add_react_common_subdir(jserrorhandler)
 add_react_common_subdir(react/runtime)
 add_react_common_subdir(react/runtime/hermes)
@@ -190,6 +192,8 @@ add_library(reactnative
           $<TARGET_OBJECTS:react_nativemodule_featureflags>
           $<TARGET_OBJECTS:react_nativemodule_idlecallbacks>
           $<TARGET_OBJECTS:react_nativemodule_microtasks>
+          $<TARGET_OBJECTS:react_nativemodule_webperformance>
+          $<TARGET_OBJECTS:react_networking>
           $<TARGET_OBJECTS:react_newarchdefaults>
           $<TARGET_OBJECTS:react_performance_cdpmetrics>
           $<TARGET_OBJECTS:react_performance_timeline>
@@ -279,6 +283,8 @@ target_include_directories(reactnative
         $<TARGET_PROPERTY:react_nativemodule_featureflags,INTERFACE_INCLUDE_DIRECTORIES>
         $<TARGET_PROPERTY:react_nativemodule_idlecallbacks,INTERFACE_INCLUDE_DIRECTORIES>
         $<TARGET_PROPERTY:react_nativemodule_microtasks,INTERFACE_INCLUDE_DIRECTORIES>
+        $<TARGET_PROPERTY:react_nativemodule_webperformance,INTERFACE_INCLUDE_DIRECTORIES>
+        $<TARGET_PROPERTY:react_networking,INTERFACE_INCLUDE_DIRECTORIES>
         $<TARGET_PROPERTY:react_newarchdefaults,INTERFACE_INCLUDE_DIRECTORIES>
         $<TARGET_PROPERTY:react_performance_cdpmetrics,INTERFACE_INCLUDE_DIRECTORIES>
         $<TARGET_PROPERTY:react_performance_timeline,INTERFACE_INCLUDE_DIRECTORIES>

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

@@ -20,6 +20,6 @@ target_include_directories(react_devsupportjni PUBLIC .)
 target_link_libraries(react_devsupportjni
         fbjni
         jsinspector
-        jsinspector_network)
+        react_networking)
 
 target_compile_reactnative_options(react_devsupportjni PRIVATE)

packages/react-native/ReactAndroid/src/main/jni/react/devsupport/JInspectorNetworkReporter.cpp

@@ -7,7 +7,7 @@
 
 #include "JInspectorNetworkReporter.h"
 
-#include <jsinspector-modern/network/NetworkReporter.h>
+#include <react/networking/NetworkReporter.h>
 
 #include <cstddef>
 #include <string>

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<<f9c4f8d97edff1b016873b0a6121b76b>>
+ * @generated SignedSource<<be39ff0cb3b7c5881510b1528c17465a>>
  */
 
 /**
@@ -309,6 +309,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool enableWebPerformanceAPIsByDefault() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableWebPerformanceAPIsByDefault");
+    return method(javaProvider_);
+  }
+
   bool fixMappingOfEventPrioritiesBetweenFabricAndReact() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("fixMappingOfEventPrioritiesBetweenFabricAndReact");
@@ -333,6 +339,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool overrideBySynchronousMountPropsAtMountingAndroid() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("overrideBySynchronousMountPropsAtMountingAndroid");
+    return method(javaProvider_);
+  }
+
   bool perfMonitorV2Enabled() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("perfMonitorV2Enabled");
@@ -682,6 +694,11 @@ bool JReactNativeFeatureFlagsCxxInterop::enableVirtualViewWindowFocusDetection(
   return ReactNativeFeatureFlags::enableVirtualViewWindowFocusDetection();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::enableWebPerformanceAPIsByDefault(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableWebPerformanceAPIsByDefault();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::fixMappingOfEventPrioritiesBetweenFabricAndReact(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::fixMappingOfEventPrioritiesBetweenFabricAndReact();
@@ -702,6 +719,11 @@ bool JReactNativeFeatureFlagsCxxInterop::hideOffscreenVirtualViewsOnIOS(
   return ReactNativeFeatureFlags::hideOffscreenVirtualViewsOnIOS();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::overrideBySynchronousMountPropsAtMountingAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::overrideBySynchronousMountPropsAtMountingAndroid();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::perfMonitorV2Enabled(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::perfMonitorV2Enabled();
@@ -968,6 +990,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableVirtualViewWindowFocusDetection",
         JReactNativeFeatureFlagsCxxInterop::enableVirtualViewWindowFocusDetection),
+      makeNativeMethod(
+        "enableWebPerformanceAPIsByDefault",
+        JReactNativeFeatureFlagsCxxInterop::enableWebPerformanceAPIsByDefault),
       makeNativeMethod(
         "fixMappingOfEventPrioritiesBetweenFabricAndReact",
         JReactNativeFeatureFlagsCxxInterop::fixMappingOfEventPrioritiesBetweenFabricAndReact),
@@ -980,6 +1005,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "hideOffscreenVirtualViewsOnIOS",
         JReactNativeFeatureFlagsCxxInterop::hideOffscreenVirtualViewsOnIOS),
+      makeNativeMethod(
+        "overrideBySynchronousMountPropsAtMountingAndroid",
+        JReactNativeFeatureFlagsCxxInterop::overrideBySynchronousMountPropsAtMountingAndroid),
       makeNativeMethod(
         "perfMonitorV2Enabled",
         JReactNativeFeatureFlagsCxxInterop::perfMonitorV2Enabled),

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<<6a98f8398948f8d56e51d3eff19c5d05>>
+ * @generated SignedSource<<8cd0afd7badb6739b4e8f9b0e630677c>>
  */
 
 /**
@@ -165,6 +165,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableVirtualViewWindowFocusDetection(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool enableWebPerformanceAPIsByDefault(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool fixMappingOfEventPrioritiesBetweenFabricAndReact(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
@@ -177,6 +180,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool hideOffscreenVirtualViewsOnIOS(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool overrideBySynchronousMountPropsAtMountingAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool perfMonitorV2Enabled(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

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

@@ -28,7 +28,7 @@ target_compile_reactnative_options(hermes_executor PRIVATE)
 if(${CMAKE_BUILD_TYPE} MATCHES Debug OR REACT_NATIVE_DEBUG_OPTIMIZED)
   target_compile_options(hermes_executor PRIVATE -DHERMES_ENABLE_DEBUGGER=1)
 
-  if (DEFINED HERMES_V1_ENABLED)
+  if (HERMES_V1_ENABLED)
         target_compile_options(hermes_executor PRIVATE -DHERMES_V1_ENABLED=1)
   endif()
 endif()

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

@@ -30,7 +30,7 @@ target_compile_reactnative_options(hermesinstancejni PRIVATE)
 if(${CMAKE_BUILD_TYPE} MATCHES Debug OR REACT_NATIVE_DEBUG_OPTIMIZED)
   target_compile_options(hermesinstancejni PRIVATE -DHERMES_ENABLE_DEBUGGER=1)
 
-  if (DEFINED HERMES_V1_ENABLED)
+  if (HERMES_V1_ENABLED)
         target_compile_options(hermesinstancejni PRIVATE -DHERMES_V1_ENABLED=1)
   endif()
 endif ()

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

@@ -20,7 +20,7 @@ target_compile_reactnative_options(rninstance PRIVATE)
 if(${CMAKE_BUILD_TYPE} MATCHES Debug OR REACT_NATIVE_DEBUG_OPTIMIZED)
   target_compile_options(rninstance PRIVATE -DHERMES_ENABLE_DEBUGGER=1)
 
-  if (DEFINED HERMES_V1_ENABLED)
+  if (HERMES_V1_ENABLED)
         target_compile_options(rninstance PRIVATE -DHERMES_V1_ENABLED=1)
   endif()
 endif ()

packages/react-native/ReactCommon/hermes/executor/CMakeLists.txt

@@ -33,7 +33,7 @@ if(${CMAKE_BUILD_TYPE} MATCHES Debug OR REACT_NATIVE_DEBUG_OPTIMIZED)
                 -DHERMES_ENABLE_DEBUGGER=1
         )
 
-        if (DEFINED HERMES_V1_ENABLED)
+        if (HERMES_V1_ENABLED)
                 target_compile_options(hermes_executor_common PRIVATE -DHERMES_V1_ENABLED=1)
         endif()
 else()

packages/react-native/ReactCommon/hermes/inspector-modern/CMakeLists.txt

@@ -24,7 +24,7 @@ if(${CMAKE_BUILD_TYPE} MATCHES Debug OR REACT_NATIVE_DEBUG_OPTIMIZED)
                 -DHERMES_ENABLE_DEBUGGER=1
         )
 
-        if (DEFINED HERMES_V1_ENABLED)
+        if (HERMES_V1_ENABLED)
                 target_compile_options(hermes_inspector_modern PRIVATE -DHERMES_V1_ENABLED=1)
         endif()
 endif()

packages/react-native/ReactCommon/jsinspector-modern/Base64.h

@@ -15,16 +15,16 @@ namespace facebook::react::jsinspector_modern {
 namespace {
 // Vendored from Folly
 // https://github.com/facebook/folly/blob/v2024.07.08.00/folly/detail/base64_detail/Base64Scalar.h
-constexpr char kBase64Charset[] =
+constexpr std::string_view kBase64Charset =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
-constexpr char kBase64URLCharset[] =
+constexpr std::string_view kBase64URLCharset =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
 
 template <bool isURL>
 struct Base64ScalarImpl {
   static constexpr const char* kCharset =
-      isURL ? kBase64URLCharset : kBase64Charset;
+      isURL ? kBase64URLCharset.data() : kBase64Charset.data();
 
   // 0, 1 or 2 bytes
   static constexpr char* encodeTail(const char* f, const char* l, char* o) {

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

@@ -11,7 +11,7 @@
 #include "Base64.h"
 #include "Utf8.h"
 
-#include <jsinspector-modern/network/NetworkReporter.h>
+#include <jsinspector-modern/network/NetworkHandler.h>
 
 #include <sstream>
 #include <tuple>
@@ -272,19 +272,19 @@ bool NetworkIOAgent::handleRequest(
   }
 
   if (InspectorFlags::getInstance().getNetworkInspectionEnabled()) {
-    auto& networkReporter = NetworkReporter::getInstance();
+    auto& networkHandler = NetworkHandler::getInstance();
 
     // @cdp Network.enable support is experimental.
     if (req.method == "Network.enable") {
-      networkReporter.setFrontendChannel(frontendChannel_);
-      networkReporter.enableDebugging();
+      networkHandler.setFrontendChannel(frontendChannel_);
+      networkHandler.enable();
       frontendChannel_(cdp::jsonResult(req.id));
       return true;
     }
 
     // @cdp Network.disable support is experimental.
     if (req.method == "Network.disable") {
-      networkReporter.disableDebugging();
+      networkHandler.disable();
       frontendChannel_(cdp::jsonResult(req.id));
       return true;
     }
@@ -497,9 +497,9 @@ void NetworkIOAgent::handleGetResponseBody(const cdp::PreparsedRequest& req) {
     return;
   }
 
-  auto& networkReporter = NetworkReporter::getInstance();
+  auto& networkHandler = NetworkHandler::getInstance();
 
-  if (!networkReporter.isDebuggingEnabled()) {
+  if (!networkHandler.isEnabled()) {
     frontendChannel_(cdp::jsonError(
         requestId,
         cdp::ErrorCode::InvalidRequest,
@@ -508,7 +508,7 @@ void NetworkIOAgent::handleGetResponseBody(const cdp::PreparsedRequest& req) {
   }
 
   auto storedResponse =
-      networkReporter.getResponseBody(req.params.at("requestId").asString());
+      networkHandler.getResponseBody(req.params.at("requestId").asString());
 
   if (!storedResponse) {
     frontendChannel_(cdp::jsonError(

packages/react-native/ReactCommon/jsinspector-modern/PerfMonitorV2.cpp

@@ -50,7 +50,8 @@ void PerfMonitorUpdateHandler::handlePerfMetricsUpdate(
     }
 
     auto responsivenessScore = getInteractionScore(duration);
-    auto ttl = responsivenessScore == InteractionResponsivenessScore::Poor
+    auto ttl =
+        responsivenessScore == InteractionResponsivenessScore::NeedsImprovement
         ? BAD_EVENT_TTL
         : DEFAULT_TTL;
 

packages/react-native/ReactCommon/jsinspector-modern/network/CMakeLists.txt

@@ -24,6 +24,4 @@ target_include_directories(jsinspector_network PUBLIC ${REACT_COMMON_DIR})
 target_link_libraries(jsinspector_network
         folly_runtime
         glog
-        jsinspector_cdp
-        react_performance_timeline
-        react_timing)
+        jsinspector_cdp)

packages/react-native/ReactCommon/jsinspector-modern/network/CdpNetwork.cpp

@@ -27,15 +27,6 @@ folly::dynamic headersToDynamic(const std::optional<Headers>& headers) {
 
 } // namespace
 
-/* static */ Request Request::fromInputParams(const RequestInfo& requestInfo) {
-  return {
-      .url = requestInfo.url,
-      .method = requestInfo.httpMethod,
-      .headers = requestInfo.headers,
-      .postData = requestInfo.httpBody,
-  };
-}
-
 folly::dynamic Request::toDynamic() const {
   folly::dynamic result = folly::dynamic::object;
 
@@ -48,16 +39,16 @@ folly::dynamic Request::toDynamic() const {
 }
 
 /* static */ Response Response::fromInputParams(
-    const ResponseInfo& responseInfo,
+    const std::string& url,
+    uint16_t status,
+    const std::optional<Headers>& headers,
     int encodedDataLength) {
-  auto headers = responseInfo.headers.value_or(Headers());
-
   return {
-      .url = responseInfo.url,
-      .status = responseInfo.statusCode,
-      .statusText = httpReasonPhrase(responseInfo.statusCode),
+      .url = url,
+      .status = status,
+      .statusText = httpReasonPhrase(status),
       .headers = headers,
-      .mimeType = mimeTypeFromHeaders(headers),
+      .mimeType = mimeTypeFromHeaders(headers.value_or(Headers())),
       .encodedDataLength = encodedDataLength,
   };
 }

packages/react-native/ReactCommon/jsinspector-modern/network/CdpNetwork.h

@@ -7,8 +7,6 @@
 
 #pragma once
 
-#include "NetworkTypes.h"
-
 #include <folly/dynamic.h>
 
 #include <string>
@@ -18,6 +16,8 @@
 
 namespace facebook::react::jsinspector_modern::cdp::network {
 
+using Headers = std::map<std::string, std::string>;
+
 /**
  * https://chromedevtools.github.io/devtools-protocol/tot/Network/#type-Request
  */
@@ -27,12 +27,6 @@ struct Request {
   std::optional<Headers> headers;
   std::optional<std::string> postData;
 
-  /**
-   * Convenience function to construct a `Request` from the generic
-   * `RequestInfo` input object.
-   */
-  static Request fromInputParams(const RequestInfo& requestInfo);
-
   folly::dynamic toDynamic() const;
 };
 
@@ -52,7 +46,9 @@ struct Response {
    * `ResponseInfo` input object.
    */
   static Response fromInputParams(
-      const ResponseInfo& responseInfo,
+      const std::string& url,
+      uint16_t status,
+      const std::optional<Headers>& headers,
       int encodedDataLength);
 
   folly::dynamic toDynamic() const;

packages/react-native/ReactCommon/jsinspector-modern/network/HttpUtils.cpp

@@ -146,7 +146,8 @@ std::string httpReasonPhrase(uint16_t status) {
   return "<Unknown>";
 }
 
-std::string mimeTypeFromHeaders(const Headers& headers) {
+std::string mimeTypeFromHeaders(
+    const std::map<std::string, std::string>& headers) {
   std::string mimeType = "application/octet-stream";
 
   for (const auto& [name, value] : headers) {

packages/react-native/ReactCommon/jsinspector-modern/network/HttpUtils.h

@@ -7,8 +7,7 @@
 
 #pragma once
 
-#include "NetworkTypes.h"
-
+#include <map>
 #include <string>
 
 namespace facebook::react::jsinspector_modern {
@@ -22,6 +21,7 @@ std::string httpReasonPhrase(uint16_t status);
  * Get the MIME type for a response based on the 'Content-Type' header. If
  * the header is not present, returns 'application/octet-stream'.
  */
-std::string mimeTypeFromHeaders(const Headers& headers);
+std::string mimeTypeFromHeaders(
+    const std::map<std::string, std::string>& headers);
 
 } // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.cpp

@@ -0,0 +1,209 @@
+/*
+ * 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 "NetworkHandler.h"
+
+#include <jsinspector-modern/cdp/CdpJson.h>
+
+#include <glog/logging.h>
+#include <chrono>
+
+namespace facebook::react::jsinspector_modern {
+
+namespace {
+
+/**
+ * Get the current Unix timestamp in seconds (µs precision, CDP format).
+ */
+double getCurrentUnixTimestampSeconds() {
+  auto now = std::chrono::system_clock::now().time_since_epoch();
+  auto seconds = std::chrono::duration_cast<std::chrono::seconds>(now).count();
+  auto micros =
+      std::chrono::duration_cast<std::chrono::microseconds>(now).count() %
+      1000000;
+
+  return static_cast<double>(seconds) +
+      (static_cast<double>(micros) / 1000000.0);
+}
+
+} // namespace
+
+NetworkHandler& NetworkHandler::getInstance() {
+  static NetworkHandler instance;
+  return instance;
+}
+
+void NetworkHandler::setFrontendChannel(FrontendChannel frontendChannel) {
+  frontendChannel_ = std::move(frontendChannel);
+}
+
+bool NetworkHandler::enable() {
+  if (enabled_.load(std::memory_order_acquire)) {
+    return false;
+  }
+
+  enabled_.store(true, std::memory_order_release);
+  return true;
+}
+
+bool NetworkHandler::disable() {
+  if (!enabled_.load(std::memory_order_acquire)) {
+    return false;
+  }
+
+  enabled_.store(false, std::memory_order_release);
+  requestBodyBuffer_.clear();
+  return true;
+}
+
+void NetworkHandler::onRequestWillBeSent(
+    const std::string& requestId,
+    const cdp::network::Request& request,
+    const std::optional<cdp::network::Response>& redirectResponse) {
+  if (!isEnabledNoSync()) {
+    return;
+  }
+
+  double timestamp = getCurrentUnixTimestampSeconds();
+  auto params = cdp::network::RequestWillBeSentParams{
+      .requestId = requestId,
+      .loaderId = "",
+      .documentURL = "mobile",
+      .request = request,
+      // NOTE: Both timestamp and wallTime use the same unit, however wallTime
+      // is relative to an "arbitrary epoch". In our implementation, use the
+      // Unix epoch for both.
+      .timestamp = timestamp,
+      .wallTime = timestamp,
+      .initiator = folly::dynamic::object("type", "script"),
+      .redirectHasExtraInfo = redirectResponse.has_value(),
+      .redirectResponse = redirectResponse,
+  };
+
+  frontendChannel_(
+      cdp::jsonNotification("Network.requestWillBeSent", params.toDynamic()));
+}
+
+void NetworkHandler::onRequestWillBeSentExtraInfo(
+    const std::string& requestId,
+    const Headers& headers) {
+  if (!isEnabledNoSync()) {
+    return;
+  }
+
+  auto params = cdp::network::RequestWillBeSentExtraInfoParams{
+      .requestId = requestId,
+      .headers = headers,
+      .connectTiming = {.requestTime = getCurrentUnixTimestampSeconds()},
+  };
+
+  frontendChannel_(cdp::jsonNotification(
+      "Network.requestWillBeSentExtraInfo", params.toDynamic()));
+}
+
+void NetworkHandler::onResponseReceived(
+    const std::string& requestId,
+    const cdp::network::Response& response) {
+  if (!isEnabledNoSync()) {
+    return;
+  }
+
+  auto resourceType = cdp::network::resourceTypeFromMimeType(response.mimeType);
+  resourceTypeMap_.emplace(requestId, resourceType);
+
+  auto params = cdp::network::ResponseReceivedParams{
+      .requestId = requestId,
+      .loaderId = "",
+      .timestamp = getCurrentUnixTimestampSeconds(),
+      .type = resourceType,
+      .response = response,
+      .hasExtraInfo = false,
+  };
+
+  frontendChannel_(
+      cdp::jsonNotification("Network.responseReceived", params.toDynamic()));
+}
+
+void NetworkHandler::onDataReceived(
+    const std::string& requestId,
+    int dataLength,
+    int encodedDataLength) {
+  if (!isEnabledNoSync()) {
+    return;
+  }
+
+  auto params = cdp::network::DataReceivedParams{
+      .requestId = requestId,
+      .timestamp = getCurrentUnixTimestampSeconds(),
+      .dataLength = dataLength,
+      .encodedDataLength = encodedDataLength,
+  };
+
+  frontendChannel_(
+      cdp::jsonNotification("Network.dataReceived", params.toDynamic()));
+}
+
+void NetworkHandler::onLoadingFinished(
+    const std::string& requestId,
+    int encodedDataLength) {
+  if (!isEnabledNoSync()) {
+    return;
+  }
+
+  auto params = cdp::network::LoadingFinishedParams{
+      .requestId = requestId,
+      .timestamp = getCurrentUnixTimestampSeconds(),
+      .encodedDataLength = encodedDataLength,
+  };
+
+  frontendChannel_(
+      cdp::jsonNotification("Network.loadingFinished", params.toDynamic()));
+}
+
+void NetworkHandler::onLoadingFailed(
+    const std::string& requestId,
+    bool cancelled) const {
+  if (!isEnabledNoSync()) {
+    return;
+  }
+
+  auto params = cdp::network::LoadingFailedParams{
+      .requestId = requestId,
+      .timestamp = getCurrentUnixTimestampSeconds(),
+      .type = resourceTypeMap_.find(requestId) != resourceTypeMap_.end()
+          ? resourceTypeMap_.at(requestId)
+          : "Other",
+      .errorText = cancelled ? "net::ERR_ABORTED" : "net::ERR_FAILED",
+      .canceled = cancelled,
+  };
+
+  frontendChannel_(
+      cdp::jsonNotification("Network.loadingFailed", params.toDynamic()));
+}
+
+void NetworkHandler::storeResponseBody(
+    const std::string& requestId,
+    std::string_view body,
+    bool base64Encoded) {
+  std::lock_guard<std::mutex> lock(requestBodyMutex_);
+  requestBodyBuffer_.put(requestId, body, base64Encoded);
+}
+
+std::optional<std::tuple<std::string, bool>> NetworkHandler::getResponseBody(
+    const std::string& requestId) {
+  std::lock_guard<std::mutex> lock(requestBodyMutex_);
+  auto responseBody = requestBodyBuffer_.get(requestId);
+
+  if (responseBody == nullptr) {
+    return std::nullopt;
+  }
+
+  return std::make_optional<std::tuple<std::string, bool>>(
+      responseBody->data, responseBody->base64Encoded);
+}
+
+} // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.h

@@ -0,0 +1,147 @@
+/*
+ * 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 "BoundedRequestBuffer.h"
+#include "CdpNetwork.h"
+
+#include <folly/dynamic.h>
+
+#include <atomic>
+#include <mutex>
+#include <string>
+#include <tuple>
+
+namespace facebook::react::jsinspector_modern {
+
+/**
+ * A callback that can be used to send debugger messages (method responses and
+ * events) to the frontend. The message must be a JSON-encoded string.
+ * The callback may be called from any thread.
+ */
+using FrontendChannel = std::function<void(std::string_view messageJson)>;
+
+using Headers = std::map<std::string, std::string>;
+
+/**
+ * [Experimental] Handler for reporting network events via CDP.
+ */
+class NetworkHandler {
+ public:
+  static NetworkHandler& getInstance();
+
+  /**
+   * Set the channel used to send CDP events to the frontend. This should be
+   * supplied before calling `enable`.
+   */
+  void setFrontendChannel(FrontendChannel frontendChannel);
+
+  /**
+   * Enable network debugging. Returns `false` if already enabled.
+   *
+   * @cdp Network.enable
+   */
+  bool enable();
+
+  /**
+   * Disable network debugging. Returns `false` if not initially enabled.
+   *
+   * @cdp Network.disable
+   */
+  bool disable();
+
+  /**
+   * Returns whether network debugging is currently enabled.
+   */
+  inline bool isEnabled() const {
+    return enabled_.load(std::memory_order_acquire);
+  }
+
+  /**
+   * @cdp Network.requestWillBeSent
+   */
+  void onRequestWillBeSent(
+      const std::string& requestId,
+      const cdp::network::Request& request,
+      const std::optional<cdp::network::Response>& redirectResponse);
+
+  /**
+   * @cdp Network.requestWillBeSentExtraInfo
+   */
+  void onRequestWillBeSentExtraInfo(
+      const std::string& requestId,
+      const Headers& headers);
+
+  /**
+   * @cdp Network.responseReceived
+   */
+  void onResponseReceived(
+      const std::string& requestId,
+      const cdp::network::Response& response);
+
+  /**
+   * @cdp Network.dataReceived
+   */
+  void onDataReceived(
+      const std::string& requestId,
+      int dataLength,
+      int encodedDataLength);
+
+  /**
+   * @cdp Network.loadingFinished
+   */
+  void onLoadingFinished(const std::string& requestId, int encodedDataLength);
+
+  /**
+   * @cdp Network.loadingFailed
+   */
+  void onLoadingFailed(const std::string& requestId, bool cancelled) const;
+
+  /**
+   * Store the fetched response body for a text or image network response.
+   *
+   * Reponse bodies are stored in a bounded buffer with a fixed maximum memory
+   * size, where oldest responses will be evicted if the buffer is exceeded.
+   *
+   * Should be called after checking \ref NetworkHandler::isEnabled.
+   */
+  void storeResponseBody(
+      const std::string& requestId,
+      std::string_view body,
+      bool base64Encoded);
+
+  /**
+   * Retrieve a stored response body for a given request ID.
+   *
+   * \returns An optional tuple of [responseBody, base64Encoded]. Returns
+   * nullopt if no entry is found in the buffer.
+   */
+  std::optional<std::tuple<std::string, bool>> getResponseBody(
+      const std::string& requestId);
+
+ private:
+  NetworkHandler() = default;
+  NetworkHandler(const NetworkHandler&) = delete;
+  NetworkHandler& operator=(const NetworkHandler&) = delete;
+  ~NetworkHandler() = default;
+
+  std::atomic<bool> enabled_{false};
+
+  inline bool isEnabledNoSync() const {
+    return enabled_.load(std::memory_order_relaxed);
+  }
+
+  FrontendChannel frontendChannel_;
+
+  std::map<std::string, std::string> resourceTypeMap_{};
+
+  BoundedRequestBuffer requestBodyBuffer_{};
+  std::mutex requestBodyMutex_;
+};
+
+} // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/network/NetworkReporter.cpp

@@ -1,316 +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 "NetworkReporter.h"
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-#include "CdpNetwork.h"
-#endif
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-#include <jsinspector-modern/cdp/CdpJson.h>
-#endif
-#include <react/featureflags/ReactNativeFeatureFlags.h>
-#include <react/performance/timeline/PerformanceEntryReporter.h>
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-#include <chrono>
-#endif
-#include <glog/logging.h>
-#include <stdexcept>
-
-namespace facebook::react::jsinspector_modern {
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-namespace {
-
-/**
- * Get the current Unix timestamp in seconds (µs precision, CDP format).
- */
-double getCurrentUnixTimestampSeconds() {
-  auto now = std::chrono::system_clock::now().time_since_epoch();
-  auto seconds = std::chrono::duration_cast<std::chrono::seconds>(now).count();
-  auto micros =
-      std::chrono::duration_cast<std::chrono::microseconds>(now).count() %
-      1000000;
-
-  return static_cast<double>(seconds) +
-      (static_cast<double>(micros) / 1000000.0);
-}
-
-} // namespace
-#endif
-
-NetworkReporter& NetworkReporter::getInstance() {
-  static NetworkReporter instance;
-  return instance;
-}
-
-void NetworkReporter::setFrontendChannel(FrontendChannel frontendChannel) {
-  frontendChannel_ = std::move(frontendChannel);
-}
-
-bool NetworkReporter::enableDebugging() {
-  if (debuggingEnabled_.load(std::memory_order_acquire)) {
-    return false;
-  }
-
-  debuggingEnabled_.store(true, std::memory_order_release);
-  return true;
-}
-
-bool NetworkReporter::disableDebugging() {
-  if (!debuggingEnabled_.load(std::memory_order_acquire)) {
-    return false;
-  }
-
-  debuggingEnabled_.store(false, std::memory_order_release);
-  requestBodyBuffer_.clear();
-  return true;
-}
-
-void NetworkReporter::reportRequestStart(
-    const std::string& requestId,
-    const RequestInfo& requestInfo,
-    int encodedDataLength,
-    const std::optional<ResponseInfo>& redirectResponse) {
-  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
-    auto now = HighResTimeStamp::now();
-
-    // All builds: Annotate PerformanceResourceTiming metadata
-    {
-      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
-      perfTimingsBuffer_.emplace(
-          requestId,
-          ResourceTimingData{
-              .url = requestInfo.url,
-              .fetchStart = now,
-              .requestStart = now,
-          });
-    }
-  }
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-  // Debug build: CDP event handling
-  if (!isDebuggingEnabledNoSync()) {
-    return;
-  }
-
-  double timestamp = getCurrentUnixTimestampSeconds();
-  auto request = cdp::network::Request::fromInputParams(requestInfo);
-  auto params = cdp::network::RequestWillBeSentParams{
-      .requestId = requestId,
-      .loaderId = "",
-      .documentURL = "mobile",
-      .request = std::move(request),
-      // NOTE: Both timestamp and wallTime use the same unit, however wallTime
-      // is relative to an "arbitrary epoch". In our implementation, use the
-      // Unix epoch for both.
-      .timestamp = timestamp,
-      .wallTime = timestamp,
-      .initiator = folly::dynamic::object("type", "script"),
-      .redirectHasExtraInfo = redirectResponse.has_value(),
-  };
-
-  if (redirectResponse.has_value()) {
-    params.redirectResponse = cdp::network::Response::fromInputParams(
-        redirectResponse.value(), encodedDataLength);
-  }
-
-  frontendChannel_(
-      cdp::jsonNotification("Network.requestWillBeSent", params.toDynamic()));
-#endif
-}
-
-void NetworkReporter::reportConnectionTiming(
-    const std::string& requestId,
-    const std::optional<Headers>& headers) {
-  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
-    auto now = HighResTimeStamp::now();
-
-    // All builds: Annotate PerformanceResourceTiming metadata
-    {
-      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
-      auto it = perfTimingsBuffer_.find(requestId);
-      if (it != perfTimingsBuffer_.end()) {
-        it->second.connectStart = now;
-      }
-    }
-  }
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-  // Debug build: CDP event handling
-  if (!isDebuggingEnabledNoSync()) {
-    return;
-  }
-
-  auto params = cdp::network::RequestWillBeSentExtraInfoParams{
-      .requestId = requestId,
-      .headers = headers.value_or(Headers{}),
-      .connectTiming = {.requestTime = getCurrentUnixTimestampSeconds()},
-  };
-
-  frontendChannel_(cdp::jsonNotification(
-      "Network.requestWillBeSentExtraInfo", params.toDynamic()));
-#endif
-}
-
-void NetworkReporter::reportResponseStart(
-    const std::string& requestId,
-    const ResponseInfo& responseInfo,
-    int encodedDataLength) {
-  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
-    auto now = HighResTimeStamp::now();
-
-    // All builds: Annotate PerformanceResourceTiming metadata
-    {
-      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
-      auto it = perfTimingsBuffer_.find(requestId);
-      if (it != perfTimingsBuffer_.end()) {
-        it->second.connectEnd = now;
-        it->second.responseStart = now;
-        it->second.responseStatus = responseInfo.statusCode;
-      }
-    }
-  }
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-  // Debug build: CDP event handling
-  if (!isDebuggingEnabledNoSync()) {
-    return;
-  }
-
-  auto response =
-      cdp::network::Response::fromInputParams(responseInfo, encodedDataLength);
-  auto resourceType = cdp::network::resourceTypeFromMimeType(response.mimeType);
-  resourceTypeMap_.emplace(requestId, resourceType);
-
-  auto params = cdp::network::ResponseReceivedParams{
-      .requestId = requestId,
-      .loaderId = "",
-      .timestamp = getCurrentUnixTimestampSeconds(),
-      .type = resourceType,
-      .response = response,
-      .hasExtraInfo = false,
-  };
-
-  frontendChannel_(
-      cdp::jsonNotification("Network.responseReceived", params.toDynamic()));
-#endif
-}
-
-void NetworkReporter::reportDataReceived(
-    const std::string& requestId,
-    int dataLength,
-    const std::optional<int>& encodedDataLength) {
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-  // Debug build: CDP event handling
-  if (!isDebuggingEnabledNoSync()) {
-    return;
-  }
-
-  auto params = cdp::network::DataReceivedParams{
-      .requestId = requestId,
-      .timestamp = getCurrentUnixTimestampSeconds(),
-      .dataLength = dataLength,
-      .encodedDataLength = encodedDataLength.value_or(dataLength),
-  };
-
-  frontendChannel_(
-      cdp::jsonNotification("Network.dataReceived", params.toDynamic()));
-#endif
-}
-
-void NetworkReporter::reportResponseEnd(
-    const std::string& requestId,
-    int encodedDataLength) {
-  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
-    auto now = HighResTimeStamp::now();
-
-    // All builds: Report PerformanceResourceTiming event
-    {
-      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
-      auto it = perfTimingsBuffer_.find(requestId);
-      if (it != perfTimingsBuffer_.end()) {
-        auto& eventData = it->second;
-        PerformanceEntryReporter::getInstance()->reportResourceTiming(
-            eventData.url,
-            eventData.fetchStart,
-            eventData.requestStart,
-            eventData.connectStart.value_or(now),
-            eventData.connectEnd.value_or(now),
-            eventData.responseStart.value_or(now),
-            now,
-            eventData.responseStatus);
-        perfTimingsBuffer_.erase(requestId);
-      }
-    }
-  }
-
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-  // Debug build: CDP event handling
-  if (!isDebuggingEnabledNoSync()) {
-    return;
-  }
-
-  auto params = cdp::network::LoadingFinishedParams{
-      .requestId = requestId,
-      .timestamp = getCurrentUnixTimestampSeconds(),
-      .encodedDataLength = encodedDataLength,
-  };
-
-  frontendChannel_(
-      cdp::jsonNotification("Network.loadingFinished", params.toDynamic()));
-#endif
-}
-
-void NetworkReporter::reportRequestFailed(
-    const std::string& requestId,
-    bool cancelled) const {
-#ifdef REACT_NATIVE_DEBUGGER_ENABLED
-  // Debug build: CDP event handling
-  if (!isDebuggingEnabledNoSync()) {
-    return;
-  }
-
-  auto params = cdp::network::LoadingFailedParams{
-      .requestId = requestId,
-      .timestamp = getCurrentUnixTimestampSeconds(),
-      .type = resourceTypeMap_.find(requestId) != resourceTypeMap_.end()
-          ? resourceTypeMap_.at(requestId)
-          : "Other",
-      .errorText = cancelled ? "net::ERR_ABORTED" : "net::ERR_FAILED",
-      .canceled = cancelled,
-  };
-
-  frontendChannel_(
-      cdp::jsonNotification("Network.loadingFailed", params.toDynamic()));
-#endif
-}
-
-void NetworkReporter::storeResponseBody(
-    const std::string& requestId,
-    std::string_view body,
-    bool base64Encoded) {
-  std::lock_guard<std::mutex> lock(requestBodyMutex_);
-  requestBodyBuffer_.put(requestId, body, base64Encoded);
-}
-
-std::optional<std::tuple<std::string, bool>> NetworkReporter::getResponseBody(
-    const std::string& requestId) {
-  std::lock_guard<std::mutex> lock(requestBodyMutex_);
-  auto responseBody = requestBodyBuffer_.get(requestId);
-
-  if (responseBody == nullptr) {
-    return std::nullopt;
-  }
-
-  return std::make_optional<std::tuple<std::string, bool>>(
-      responseBody->data, responseBody->base64Encoded);
-}
-
-} // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/network/React-jsinspectornetwork.podspec

@@ -44,9 +44,6 @@ Pod::Spec.new do |s|
   resolve_use_frameworks(s, header_mappings_dir: "../..", module_name: module_name)
 
   add_dependency(s, "React-jsinspectorcdp", :framework_name => 'jsinspector_moderncdp')
-  add_dependency(s, "React-featureflags")
-  s.dependency "React-performancetimeline"
-  s.dependency "React-timing"
 
   add_rn_third_party_dependencies(s)
   add_rncore_dependency(s)

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<<5bd932f1d52596dad6ea86a2674170ff>>
+ * @generated SignedSource<<a4fb74cf8a68181f509794e387bf666d>>
  */
 
 /**
@@ -206,6 +206,10 @@ bool ReactNativeFeatureFlags::enableVirtualViewWindowFocusDetection() {
   return getAccessor().enableVirtualViewWindowFocusDetection();
 }
 
+bool ReactNativeFeatureFlags::enableWebPerformanceAPIsByDefault() {
+  return getAccessor().enableWebPerformanceAPIsByDefault();
+}
+
 bool ReactNativeFeatureFlags::fixMappingOfEventPrioritiesBetweenFabricAndReact() {
   return getAccessor().fixMappingOfEventPrioritiesBetweenFabricAndReact();
 }
@@ -222,6 +226,10 @@ bool ReactNativeFeatureFlags::hideOffscreenVirtualViewsOnIOS() {
   return getAccessor().hideOffscreenVirtualViewsOnIOS();
 }
 
+bool ReactNativeFeatureFlags::overrideBySynchronousMountPropsAtMountingAndroid() {
+  return getAccessor().overrideBySynchronousMountPropsAtMountingAndroid();
+}
+
 bool ReactNativeFeatureFlags::perfMonitorV2Enabled() {
   return getAccessor().perfMonitorV2Enabled();
 }

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<<3cde1e9bcf234515551ba57ecf02e3a7>>
+ * @generated SignedSource<<a4a98649c527be3c936c859ddc59cb33>>
  */
 
 /**
@@ -264,6 +264,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableVirtualViewWindowFocusDetection();
 
+  /**
+   * Enable Web Performance APIs (Performance Timeline, User Timings, etc.) by default.
+   */
+  RN_EXPORT static bool enableWebPerformanceAPIsByDefault();
+
   /**
    * Uses the default event priority instead of the discreet event priority by default when dispatching events from Fabric to React.
    */
@@ -284,6 +289,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool hideOffscreenVirtualViewsOnIOS();
 
+  /**
+   * Override props at mounting with synchronously mounted (i.e. direct manipulation) props from Native Animated.
+   */
+  RN_EXPORT static bool overrideBySynchronousMountPropsAtMountingAndroid();
+
   /**
    * Enable the V2 in-app Performance Monitor. This flag is global and should not be changed across React Host lifetimes.
    */

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<<bf7bb959d851abb8cd98a2eb3fa43923>>
+ * @generated SignedSource<<91188495ce43a1e1c820cdc3d6302bda>>
  */
 
 /**
@@ -839,6 +839,24 @@ bool ReactNativeFeatureFlagsAccessor::enableVirtualViewWindowFocusDetection() {
   return flagValue.value();
 }
 
+bool ReactNativeFeatureFlagsAccessor::enableWebPerformanceAPIsByDefault() {
+  auto flagValue = enableWebPerformanceAPIsByDefault_.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(45, "enableWebPerformanceAPIsByDefault");
+
+    flagValue = currentProvider_->enableWebPerformanceAPIsByDefault();
+    enableWebPerformanceAPIsByDefault_ = flagValue;
+  }
+
+  return flagValue.value();
+}
+
 bool ReactNativeFeatureFlagsAccessor::fixMappingOfEventPrioritiesBetweenFabricAndReact() {
   auto flagValue = fixMappingOfEventPrioritiesBetweenFabricAndReact_.load();
 
@@ -848,7 +866,7 @@ 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(45, "fixMappingOfEventPrioritiesBetweenFabricAndReact");
+    markFlagAsAccessed(46, "fixMappingOfEventPrioritiesBetweenFabricAndReact");
 
     flagValue = currentProvider_->fixMappingOfEventPrioritiesBetweenFabricAndReact();
     fixMappingOfEventPrioritiesBetweenFabricAndReact_ = flagValue;
@@ -866,7 +884,7 @@ 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(46, "fuseboxEnabledRelease");
+    markFlagAsAccessed(47, "fuseboxEnabledRelease");
 
     flagValue = currentProvider_->fuseboxEnabledRelease();
     fuseboxEnabledRelease_ = flagValue;
@@ -884,7 +902,7 @@ 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(47, "fuseboxNetworkInspectionEnabled");
+    markFlagAsAccessed(48, "fuseboxNetworkInspectionEnabled");
 
     flagValue = currentProvider_->fuseboxNetworkInspectionEnabled();
     fuseboxNetworkInspectionEnabled_ = flagValue;
@@ -902,7 +920,7 @@ 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(48, "hideOffscreenVirtualViewsOnIOS");
+    markFlagAsAccessed(49, "hideOffscreenVirtualViewsOnIOS");
 
     flagValue = currentProvider_->hideOffscreenVirtualViewsOnIOS();
     hideOffscreenVirtualViewsOnIOS_ = flagValue;
@@ -911,6 +929,24 @@ bool ReactNativeFeatureFlagsAccessor::hideOffscreenVirtualViewsOnIOS() {
   return flagValue.value();
 }
 
+bool ReactNativeFeatureFlagsAccessor::overrideBySynchronousMountPropsAtMountingAndroid() {
+  auto flagValue = overrideBySynchronousMountPropsAtMountingAndroid_.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(50, "overrideBySynchronousMountPropsAtMountingAndroid");
+
+    flagValue = currentProvider_->overrideBySynchronousMountPropsAtMountingAndroid();
+    overrideBySynchronousMountPropsAtMountingAndroid_ = flagValue;
+  }
+
+  return flagValue.value();
+}
+
 bool ReactNativeFeatureFlagsAccessor::perfMonitorV2Enabled() {
   auto flagValue = perfMonitorV2Enabled_.load();
 
@@ -920,7 +956,7 @@ 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(49, "perfMonitorV2Enabled");
+    markFlagAsAccessed(51, "perfMonitorV2Enabled");
 
     flagValue = currentProvider_->perfMonitorV2Enabled();
     perfMonitorV2Enabled_ = flagValue;
@@ -938,7 +974,7 @@ 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(50, "preparedTextCacheSize");
+    markFlagAsAccessed(52, "preparedTextCacheSize");
 
     flagValue = currentProvider_->preparedTextCacheSize();
     preparedTextCacheSize_ = flagValue;
@@ -956,7 +992,7 @@ 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(51, "preventShadowTreeCommitExhaustion");
+    markFlagAsAccessed(53, "preventShadowTreeCommitExhaustion");
 
     flagValue = currentProvider_->preventShadowTreeCommitExhaustion();
     preventShadowTreeCommitExhaustion_ = flagValue;
@@ -974,7 +1010,7 @@ 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(52, "shouldPressibilityUseW3CPointerEventsForHover");
+    markFlagAsAccessed(54, "shouldPressibilityUseW3CPointerEventsForHover");
 
     flagValue = currentProvider_->shouldPressibilityUseW3CPointerEventsForHover();
     shouldPressibilityUseW3CPointerEventsForHover_ = flagValue;
@@ -992,7 +1028,7 @@ 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(53, "skipActivityIdentityAssertionOnHostPause");
+    markFlagAsAccessed(55, "skipActivityIdentityAssertionOnHostPause");
 
     flagValue = currentProvider_->skipActivityIdentityAssertionOnHostPause();
     skipActivityIdentityAssertionOnHostPause_ = flagValue;
@@ -1010,7 +1046,7 @@ 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(54, "sweepActiveTouchOnChildNativeGesturesAndroid");
+    markFlagAsAccessed(56, "sweepActiveTouchOnChildNativeGesturesAndroid");
 
     flagValue = currentProvider_->sweepActiveTouchOnChildNativeGesturesAndroid();
     sweepActiveTouchOnChildNativeGesturesAndroid_ = flagValue;
@@ -1028,7 +1064,7 @@ 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(55, "traceTurboModulePromiseRejectionsOnAndroid");
+    markFlagAsAccessed(57, "traceTurboModulePromiseRejectionsOnAndroid");
 
     flagValue = currentProvider_->traceTurboModulePromiseRejectionsOnAndroid();
     traceTurboModulePromiseRejectionsOnAndroid_ = flagValue;
@@ -1046,7 +1082,7 @@ 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(56, "updateRuntimeShadowNodeReferencesOnCommit");
+    markFlagAsAccessed(58, "updateRuntimeShadowNodeReferencesOnCommit");
 
     flagValue = currentProvider_->updateRuntimeShadowNodeReferencesOnCommit();
     updateRuntimeShadowNodeReferencesOnCommit_ = flagValue;
@@ -1064,7 +1100,7 @@ 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(57, "useAlwaysAvailableJSErrorHandling");
+    markFlagAsAccessed(59, "useAlwaysAvailableJSErrorHandling");
 
     flagValue = currentProvider_->useAlwaysAvailableJSErrorHandling();
     useAlwaysAvailableJSErrorHandling_ = flagValue;
@@ -1082,7 +1118,7 @@ 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(58, "useFabricInterop");
+    markFlagAsAccessed(60, "useFabricInterop");
 
     flagValue = currentProvider_->useFabricInterop();
     useFabricInterop_ = flagValue;
@@ -1100,7 +1136,7 @@ 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(59, "useNativeEqualsInNativeReadableArrayAndroid");
+    markFlagAsAccessed(61, "useNativeEqualsInNativeReadableArrayAndroid");
 
     flagValue = currentProvider_->useNativeEqualsInNativeReadableArrayAndroid();
     useNativeEqualsInNativeReadableArrayAndroid_ = flagValue;
@@ -1118,7 +1154,7 @@ 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(60, "useNativeTransformHelperAndroid");
+    markFlagAsAccessed(62, "useNativeTransformHelperAndroid");
 
     flagValue = currentProvider_->useNativeTransformHelperAndroid();
     useNativeTransformHelperAndroid_ = flagValue;
@@ -1136,7 +1172,7 @@ 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(61, "useNativeViewConfigsInBridgelessMode");
+    markFlagAsAccessed(63, "useNativeViewConfigsInBridgelessMode");
 
     flagValue = currentProvider_->useNativeViewConfigsInBridgelessMode();
     useNativeViewConfigsInBridgelessMode_ = flagValue;
@@ -1154,7 +1190,7 @@ 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(62, "useOptimizedEventBatchingOnAndroid");
+    markFlagAsAccessed(64, "useOptimizedEventBatchingOnAndroid");
 
     flagValue = currentProvider_->useOptimizedEventBatchingOnAndroid();
     useOptimizedEventBatchingOnAndroid_ = flagValue;
@@ -1172,7 +1208,7 @@ 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(63, "useRawPropsJsiValue");
+    markFlagAsAccessed(65, "useRawPropsJsiValue");
 
     flagValue = currentProvider_->useRawPropsJsiValue();
     useRawPropsJsiValue_ = flagValue;
@@ -1190,7 +1226,7 @@ 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(64, "useShadowNodeStateOnClone");
+    markFlagAsAccessed(66, "useShadowNodeStateOnClone");
 
     flagValue = currentProvider_->useShadowNodeStateOnClone();
     useShadowNodeStateOnClone_ = flagValue;
@@ -1208,7 +1244,7 @@ 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(65, "useTurboModuleInterop");
+    markFlagAsAccessed(67, "useTurboModuleInterop");
 
     flagValue = currentProvider_->useTurboModuleInterop();
     useTurboModuleInterop_ = flagValue;
@@ -1226,7 +1262,7 @@ 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(66, "useTurboModules");
+    markFlagAsAccessed(68, "useTurboModules");
 
     flagValue = currentProvider_->useTurboModules();
     useTurboModules_ = flagValue;
@@ -1244,7 +1280,7 @@ double ReactNativeFeatureFlagsAccessor::virtualViewHysteresisRatio() {
     // 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");
+    markFlagAsAccessed(69, "virtualViewHysteresisRatio");
 
     flagValue = currentProvider_->virtualViewHysteresisRatio();
     virtualViewHysteresisRatio_ = flagValue;
@@ -1262,7 +1298,7 @@ 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(68, "virtualViewPrerenderRatio");
+    markFlagAsAccessed(70, "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<<a449e9cf8f14bb7381d9779c764d0d7c>>
+ * @generated SignedSource<<17f7a8577d05b191010622fb58ba27f8>>
  */
 
 /**
@@ -77,10 +77,12 @@ class ReactNativeFeatureFlagsAccessor {
   bool enableVirtualViewDebugFeatures();
   bool enableVirtualViewRenderState();
   bool enableVirtualViewWindowFocusDetection();
+  bool enableWebPerformanceAPIsByDefault();
   bool fixMappingOfEventPrioritiesBetweenFabricAndReact();
   bool fuseboxEnabledRelease();
   bool fuseboxNetworkInspectionEnabled();
   bool hideOffscreenVirtualViewsOnIOS();
+  bool overrideBySynchronousMountPropsAtMountingAndroid();
   bool perfMonitorV2Enabled();
   double preparedTextCacheSize();
   bool preventShadowTreeCommitExhaustion();
@@ -112,7 +114,7 @@ class ReactNativeFeatureFlagsAccessor {
   std::unique_ptr<ReactNativeFeatureFlagsProvider> currentProvider_;
   bool wasOverridden_;
 
-  std::array<std::atomic<const char*>, 69> accessedFeatureFlags_;
+  std::array<std::atomic<const char*>, 71> accessedFeatureFlags_;
 
   std::atomic<std::optional<bool>> commonTestFlag_;
   std::atomic<std::optional<bool>> cdpInteractionMetricsEnabled_;
@@ -159,10 +161,12 @@ class ReactNativeFeatureFlagsAccessor {
   std::atomic<std::optional<bool>> enableVirtualViewDebugFeatures_;
   std::atomic<std::optional<bool>> enableVirtualViewRenderState_;
   std::atomic<std::optional<bool>> enableVirtualViewWindowFocusDetection_;
+  std::atomic<std::optional<bool>> enableWebPerformanceAPIsByDefault_;
   std::atomic<std::optional<bool>> fixMappingOfEventPrioritiesBetweenFabricAndReact_;
   std::atomic<std::optional<bool>> fuseboxEnabledRelease_;
   std::atomic<std::optional<bool>> fuseboxNetworkInspectionEnabled_;
   std::atomic<std::optional<bool>> hideOffscreenVirtualViewsOnIOS_;
+  std::atomic<std::optional<bool>> overrideBySynchronousMountPropsAtMountingAndroid_;
   std::atomic<std::optional<bool>> perfMonitorV2Enabled_;
   std::atomic<std::optional<double>> preparedTextCacheSize_;
   std::atomic<std::optional<bool>> preventShadowTreeCommitExhaustion_;

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<<6d8adaa4b960407540afb1d6e42a3840>>
+ * @generated SignedSource<<f387394359fc15af1ecad288f08fefe7>>
  */
 
 /**
@@ -207,6 +207,10 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
     return false;
   }
 
+  bool enableWebPerformanceAPIsByDefault() override {
+    return false;
+  }
+
   bool fixMappingOfEventPrioritiesBetweenFabricAndReact() override {
     return false;
   }
@@ -223,6 +227,10 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
     return false;
   }
 
+  bool overrideBySynchronousMountPropsAtMountingAndroid() override {
+    return false;
+  }
+
   bool perfMonitorV2Enabled() override {
     return false;
   }

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<<ccd274f2ece9c85f23dd87e74d446ecb>>
+ * @generated SignedSource<<e70173d99a68270c77447cd13c556f6d>>
  */
 
 /**
@@ -450,6 +450,15 @@ class ReactNativeFeatureFlagsDynamicProvider : public ReactNativeFeatureFlagsDef
     return ReactNativeFeatureFlagsDefaults::enableVirtualViewWindowFocusDetection();
   }
 
+  bool enableWebPerformanceAPIsByDefault() override {
+    auto value = values_["enableWebPerformanceAPIsByDefault"];
+    if (!value.isNull()) {
+      return value.getBool();
+    }
+
+    return ReactNativeFeatureFlagsDefaults::enableWebPerformanceAPIsByDefault();
+  }
+
   bool fixMappingOfEventPrioritiesBetweenFabricAndReact() override {
     auto value = values_["fixMappingOfEventPrioritiesBetweenFabricAndReact"];
     if (!value.isNull()) {
@@ -486,6 +495,15 @@ class ReactNativeFeatureFlagsDynamicProvider : public ReactNativeFeatureFlagsDef
     return ReactNativeFeatureFlagsDefaults::hideOffscreenVirtualViewsOnIOS();
   }
 
+  bool overrideBySynchronousMountPropsAtMountingAndroid() override {
+    auto value = values_["overrideBySynchronousMountPropsAtMountingAndroid"];
+    if (!value.isNull()) {
+      return value.getBool();
+    }
+
+    return ReactNativeFeatureFlagsDefaults::overrideBySynchronousMountPropsAtMountingAndroid();
+  }
+
   bool perfMonitorV2Enabled() override {
     auto value = values_["perfMonitorV2Enabled"];
     if (!value.isNull()) {

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<<07b25b19a265e8afe53eeeffade4dfc0>>
+ * @generated SignedSource<<d8b57edf1ba256965238058533a2ea7d>>
  */
 
 /**
@@ -70,10 +70,12 @@ class ReactNativeFeatureFlagsProvider {
   virtual bool enableVirtualViewDebugFeatures() = 0;
   virtual bool enableVirtualViewRenderState() = 0;
   virtual bool enableVirtualViewWindowFocusDetection() = 0;
+  virtual bool enableWebPerformanceAPIsByDefault() = 0;
   virtual bool fixMappingOfEventPrioritiesBetweenFabricAndReact() = 0;
   virtual bool fuseboxEnabledRelease() = 0;
   virtual bool fuseboxNetworkInspectionEnabled() = 0;
   virtual bool hideOffscreenVirtualViewsOnIOS() = 0;
+  virtual bool overrideBySynchronousMountPropsAtMountingAndroid() = 0;
   virtual bool perfMonitorV2Enabled() = 0;
   virtual double preparedTextCacheSize() = 0;
   virtual bool preventShadowTreeCommitExhaustion() = 0;

packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.mm

@@ -51,7 +51,7 @@ std::vector<const RCTMethodInfo *> getMethodInfos(Class moduleClass)
   std::vector<const RCTMethodInfo *> methodInfos;
 
   Class cls = moduleClass;
-  while (cls && cls != [NSObject class] && cls != [NSProxy class]) {
+  while ((cls != nullptr) && cls != [NSObject class] && cls != [NSProxy class]) {
     unsigned int methodCount;
     Method *methods = class_copyMethodList(object_getClass(cls), &methodCount);
 
@@ -482,7 +482,7 @@ void ObjCInteropTurboModule::setInvocationArg(
         return;
       }
 
-      if (arg) {
+      if (arg != nullptr) {
         [retainedObjectsForInvocation addObject:arg];
       }
       [inv setArgument:&arg atIndex:(index) + 2];
@@ -496,7 +496,7 @@ void ObjCInteropTurboModule::setInvocationArg(
       typeInvocation.target = [RCTConvert class];
 
       void *returnValue = malloc(typeSignature.methodReturnLength);
-      if (!returnValue) {
+      if (returnValue == nullptr) {
         // CWE - 391 : Unchecked error condition
         // https://www.cvedetails.com/cwe-details/391/Unchecked-Error-Condition.html
         // https://eli.thegreenplace.net/2009/10/30/handling-out-of-memory-conditions-in-c
@@ -519,7 +519,7 @@ void ObjCInteropTurboModule::setInvocationArg(
        * RCTModuleMethod doesn't actually call into RCTConvert in this case.
        */
       id arg = [objCArg copy];
-      if (arg) {
+      if (arg != nullptr) {
         [retainedObjectsForInvocation addObject:arg];
       }
       [inv setArgument:&arg atIndex:(index) + 2];
@@ -537,7 +537,7 @@ void ObjCInteropTurboModule::setInvocationArg(
 
     RCTResponseSenderBlock arg =
         (RCTResponseSenderBlock)TurboModuleConvertUtils::convertJSIValueToObjCObject(runtime, jsiArg, jsInvoker_, YES);
-    if (arg) {
+    if (arg != nullptr) {
       [retainedObjectsForInvocation addObject:arg];
     }
     [inv setArgument:&arg atIndex:(index) + 2];

packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.mm

@@ -59,7 +59,7 @@ static jsi::Value convertNSNumberToJSINumber(jsi::Runtime &runtime, NSNumber *va
 
 static jsi::String convertNSStringToJSIString(jsi::Runtime &runtime, NSString *value)
 {
-  return jsi::String::createFromUtf8(runtime, [value UTF8String] ? [value UTF8String] : "");
+  return jsi::String::createFromUtf8(runtime, ([value UTF8String] != nullptr) ? [value UTF8String] : "");
 }
 
 static jsi::Object convertNSDictionaryToJSIObject(jsi::Runtime &runtime, NSDictionary *value)
@@ -124,7 +124,7 @@ static NSArray *convertJSIArrayToNSArray(
   for (size_t i = 0; i < size; i++) {
     // Insert kCFNull when it's `undefined` value to preserve the indices.
     id convertedObject = convertJSIValueToObjCObject(runtime, value.getValueAtIndex(runtime, i), jsInvoker, useNSNull);
-    [result addObject:convertedObject ? convertedObject : (id)kCFNull];
+    [result addObject:(convertedObject != nullptr) ? convertedObject : (id)kCFNull];
   }
   return result;
 }
@@ -142,7 +142,7 @@ static NSDictionary *convertJSIObjectToNSDictionary(
     jsi::String name = propertyNames.getValueAtIndex(runtime, i).getString(runtime);
     NSString *k = convertJSIStringToNSString(runtime, name);
     id v = convertJSIValueToObjCObject(runtime, value.getProperty(runtime, name), jsInvoker, useNSNull);
-    if (v) {
+    if (v != nullptr) {
       result[k] = v;
     }
   }
@@ -252,7 +252,7 @@ static jsi::Value convertJSErrorDetailsToJSRuntimeError(jsi::Runtime &runtime, N
 jsi::Value
 ObjCTurboModule::createPromise(jsi::Runtime &runtime, const std::string &methodName, PromiseInvocationBlock invoke)
 {
-  if (!invoke) {
+  if (invoke == nullptr) {
     return jsi::Value::undefined();
   }
 
@@ -388,7 +388,7 @@ id ObjCTurboModule::performMethodInvocation(
 
   void (^block)() = ^{
     id<RCTBridgeModule> strongModule = weakModule;
-    if (!strongModule) {
+    if (strongModule == nullptr) {
       return;
     }
 
@@ -457,7 +457,7 @@ void ObjCTurboModule::performVoidMethodInvocation(
 
   void (^block)() = ^{
     id<RCTBridgeModule> strongModule = weakModule;
-    if (!strongModule) {
+    if (strongModule == nullptr) {
       return;
     }
 
@@ -560,14 +560,14 @@ jsi::Value ObjCTurboModule::convertReturnIdToJSIValue(
  */
 NSString *ObjCTurboModule::getArgumentTypeName(jsi::Runtime &runtime, NSString *methodName, int argIndex)
 {
-  if (!methodArgumentTypeNames_) {
+  if (methodArgumentTypeNames_ == nullptr) {
     NSMutableDictionary<NSString *, NSArray<NSString *> *> *methodArgumentTypeNames = [NSMutableDictionary new];
 
     unsigned int numberOfMethods;
     Class cls = [instance_ class];
     Method *methods = class_copyMethodList(object_getClass(cls), &numberOfMethods);
 
-    if (methods) {
+    if (methods != nullptr) {
       for (unsigned int i = 0; i < numberOfMethods; i++) {
         SEL s = method_getName(methods[i]);
         NSString *mName = NSStringFromSelector(s);
@@ -597,7 +597,7 @@ NSString *ObjCTurboModule::getArgumentTypeName(jsi::Runtime &runtime, NSString *
     methodArgumentTypeNames_ = methodArgumentTypeNames;
   }
 
-  if (methodArgumentTypeNames_[methodName]) {
+  if (methodArgumentTypeNames_[methodName] != nullptr) {
     assert([methodArgumentTypeNames_[methodName] count] > argIndex);
     return methodArgumentTypeNames_[methodName][argIndex];
   }
@@ -656,7 +656,7 @@ void ObjCTurboModule::setInvocationArg(
    */
   BOOL enableModuleArgumentNSNullConversionIOS = ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS();
   id objCArg = convertJSIValueToObjCObject(runtime, arg, jsInvoker_, enableModuleArgumentNSNullConversionIOS);
-  if (objCArg) {
+  if (objCArg != nullptr) {
     NSString *methodNameNSString = @(methodName);
 
     /**
@@ -678,7 +678,7 @@ void ObjCTurboModule::setInvocationArg(
           }
 
           [inv setArgument:(void *)&convertedObjCArg atIndex:i + 2];
-          if (convertedObjCArg) {
+          if (convertedObjCArg != nullptr) {
             [retainedObjectsForInvocation addObject:convertedObjCArg];
           }
           return;
@@ -708,7 +708,7 @@ void ObjCTurboModule::setInvocationArg(
    * Insert converted args unmodified.
    */
   [inv setArgument:(void *)&objCArg atIndex:i + 2];
-  if (objCArg) {
+  if (objCArg != nullptr) {
     [retainedObjectsForInvocation addObject:objCArg];
   }
 }
@@ -848,7 +848,7 @@ jsi::Value ObjCTurboModule::invokeObjCMethod(
 
 BOOL ObjCTurboModule::hasMethodArgConversionSelector(NSString *methodName, size_t argIndex)
 {
-  return methodArgConversionSelectors_ && methodArgConversionSelectors_[methodName] &&
+  return (methodArgConversionSelectors_ != nullptr) && (methodArgConversionSelectors_[methodName] != nullptr) &&
       ![methodArgConversionSelectors_[methodName][argIndex] isEqual:(id)kCFNull];
 }
 
@@ -860,11 +860,11 @@ SEL ObjCTurboModule::getMethodArgConversionSelector(NSString *methodName, size_t
 
 void ObjCTurboModule::setMethodArgConversionSelector(NSString *methodName, size_t argIndex, NSString *fnName)
 {
-  if (!methodArgConversionSelectors_) {
+  if (methodArgConversionSelectors_ == nullptr) {
     methodArgConversionSelectors_ = [NSMutableDictionary new];
   }
 
-  if (!methodArgConversionSelectors_[methodName]) {
+  if (methodArgConversionSelectors_[methodName] == nullptr) {
     auto metaData = methodMap_.at([methodName UTF8String]);
     auto argCount = metaData.argCount;
 

packages/react-native/ReactCommon/react/nativemodule/defaults/CMakeLists.txt

@@ -21,6 +21,7 @@ target_link_libraries(react_nativemodule_defaults
         react_nativemodule_featureflags
         react_nativemodule_microtasks
         react_nativemodule_idlecallbacks
+        react_nativemodule_webperformance
 )
 target_compile_reactnative_options(react_nativemodule_defaults PRIVATE)
 target_compile_options(react_nativemodule_defaults PRIVATE -Wpedantic)

packages/react-native/ReactCommon/react/nativemodule/defaults/DefaultTurboModules.cpp

@@ -6,10 +6,12 @@
  */
 
 #include "DefaultTurboModules.h"
+#include <react/featureflags/ReactNativeFeatureFlags.h>
 #include <react/nativemodule/dom/NativeDOM.h>
 #include <react/nativemodule/featureflags/NativeReactNativeFeatureFlags.h>
 #include <react/nativemodule/idlecallbacks/NativeIdleCallbacks.h>
 #include <react/nativemodule/microtasks/NativeMicrotasks.h>
+#include <react/nativemodule/webperformance/NativePerformance.h>
 
 #ifdef REACT_NATIVE_DEBUGGER_ENABLED_DEVONLY
 #include <react/nativemodule/devtoolsruntimesettings/DevToolsRuntimeSettingsModule.h>
@@ -36,6 +38,12 @@ namespace facebook::react {
     return std::make_shared<NativeDOM>(jsInvoker);
   }
 
+  if (ReactNativeFeatureFlags::enableWebPerformanceAPIsByDefault()) {
+    if (name == NativePerformance::kModuleName) {
+      return std::make_shared<NativePerformance>(jsInvoker);
+    }
+  }
+
 #ifdef REACT_NATIVE_DEBUGGER_ENABLED_DEVONLY
   if (name == DevToolsRuntimeSettingsModule::kModuleName) {
     return std::make_shared<DevToolsRuntimeSettingsModule>(jsInvoker);

packages/react-native/ReactCommon/react/nativemodule/defaults/React-defaultsnativemodule.podspec

@@ -50,5 +50,6 @@ Pod::Spec.new do |s|
   s.dependency "React-featureflagsnativemodule"
   s.dependency "React-microtasksnativemodule"
   s.dependency "React-idlecallbacksnativemodule"
+  s.dependency "React-webperformancenativemodule"
   add_dependency(s, "React-RCTFBReactNativeSpec")
 end

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<<348005db0ceee698cd7c33f29bcf85a6>>
+ * @generated SignedSource<<702c4023cfafdd477cba85c6efe94d93>>
  */
 
 /**
@@ -269,6 +269,11 @@ bool NativeReactNativeFeatureFlags::enableVirtualViewWindowFocusDetection(
   return ReactNativeFeatureFlags::enableVirtualViewWindowFocusDetection();
 }
 
+bool NativeReactNativeFeatureFlags::enableWebPerformanceAPIsByDefault(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::enableWebPerformanceAPIsByDefault();
+}
+
 bool NativeReactNativeFeatureFlags::fixMappingOfEventPrioritiesBetweenFabricAndReact(
     jsi::Runtime& /*runtime*/) {
   return ReactNativeFeatureFlags::fixMappingOfEventPrioritiesBetweenFabricAndReact();
@@ -289,6 +294,11 @@ bool NativeReactNativeFeatureFlags::hideOffscreenVirtualViewsOnIOS(
   return ReactNativeFeatureFlags::hideOffscreenVirtualViewsOnIOS();
 }
 
+bool NativeReactNativeFeatureFlags::overrideBySynchronousMountPropsAtMountingAndroid(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::overrideBySynchronousMountPropsAtMountingAndroid();
+}
+
 bool NativeReactNativeFeatureFlags::perfMonitorV2Enabled(
     jsi::Runtime& /*runtime*/) {
   return ReactNativeFeatureFlags::perfMonitorV2Enabled();

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<<a27c4788a4b87366ef1e3ee03da53ab6>>
+ * @generated SignedSource<<96e93863588a9878db7c812435564603>>
  */
 
 /**
@@ -126,6 +126,8 @@ class NativeReactNativeFeatureFlags
 
   bool enableVirtualViewWindowFocusDetection(jsi::Runtime& runtime);
 
+  bool enableWebPerformanceAPIsByDefault(jsi::Runtime& runtime);
+
   bool fixMappingOfEventPrioritiesBetweenFabricAndReact(jsi::Runtime& runtime);
 
   bool fuseboxEnabledRelease(jsi::Runtime& runtime);
@@ -134,6 +136,8 @@ class NativeReactNativeFeatureFlags
 
   bool hideOffscreenVirtualViewsOnIOS(jsi::Runtime& runtime);
 
+  bool overrideBySynchronousMountPropsAtMountingAndroid(jsi::Runtime& runtime);
+
   bool perfMonitorV2Enabled(jsi::Runtime& runtime);
 
   double preparedTextCacheSize(jsi::Runtime& runtime);

packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTSampleLegacyModule.mm

@@ -136,14 +136,14 @@ RCT_EXPORT_SYNCHRONOUS_TYPED_METHOD(NSDictionary *, getValue : (double)x y : (NS
 {
   return @{
     @"x" : @(x),
-    @"y" : y ? y : [NSNull null],
-    @"z" : z ? z : [NSNull null],
+    @"y" : (y != nullptr) ? y : [NSNull null],
+    @"z" : (z != nullptr) ? z : [NSNull null],
   };
 }
 
 RCT_EXPORT_METHOD(getValueWithCallback : (RCTResponseSenderBlock)callback)
 {
-  if (!callback) {
+  if (callback == nullptr) {
     return;
   }
   callback(@[ @"value from callback!" ]);
@@ -154,7 +154,7 @@ RCT_EXPORT_METHOD(getValueWithPromise
                   : (RCTPromiseResolveBlock)resolve reject
                   : (RCTPromiseRejectBlock)reject)
 {
-  if (!resolve || !reject) {
+  if ((resolve == nullptr) || (reject == nullptr)) {
     return;
   }
 

packages/react-native/ReactCommon/react/nativemodule/samples/platform/ios/ReactCommon/RCTSampleTurboModule.mm

@@ -136,14 +136,14 @@ RCT_EXPORT_SYNCHRONOUS_TYPED_METHOD(NSDictionary *, getValue : (double)x y : (NS
 {
   return @{
     @"x" : @(x),
-    @"y" : y ? y : [NSNull null],
-    @"z" : z ? z : [NSNull null],
+    @"y" : (y != nullptr) ? y : [NSNull null],
+    @"z" : (z != nullptr) ? z : [NSNull null],
   };
 }
 
 RCT_EXPORT_METHOD(getValueWithCallback : (RCTResponseSenderBlock)callback)
 {
-  if (!callback) {
+  if (callback == nullptr) {
     return;
   }
   callback(@[ @"value from callback!" ]);
@@ -154,7 +154,7 @@ RCT_EXPORT_METHOD(getValueWithPromise
                   : (RCTPromiseResolveBlock)resolve reject
                   : (RCTPromiseRejectBlock)reject)
 {
-  if (!resolve || !reject) {
+  if ((resolve == nullptr) || (reject == nullptr)) {
     return;
   }
 

packages/react-native/ReactCommon/react/nativemodule/webperformance/CMakeLists.txt

@@ -7,13 +7,13 @@ cmake_minimum_required(VERSION 3.13)
 set(CMAKE_VERBOSE_MAKEFILE on)
 
 include(${REACT_COMMON_DIR}/cmake-utils/react-native-flags.cmake)
-
 file(GLOB react_nativemodule_webperformance_SRC CONFIGURE_DEPENDS *.cpp)
 add_library(react_nativemodule_webperformance OBJECT ${react_nativemodule_webperformance_SRC})
 
 target_include_directories(react_nativemodule_webperformance PUBLIC ${REACT_COMMON_DIR})
 
 target_link_libraries(react_nativemodule_webperformance
+        react_performance_timeline
         react_codegen_rncore
         react_cxxreact
 )

packages/react-native/ReactCommon/react/nativemodule/webperformance/NativePerformance.cpp

@@ -131,9 +131,18 @@ NativePerformance::NativePerformance(std::shared_ptr<CallInvoker> jsInvoker)
     : NativePerformanceCxxSpec(std::move(jsInvoker)) {}
 
 HighResTimeStamp NativePerformance::now(jsi::Runtime& /*rt*/) {
+  // This is not spec-compliant, as this is the duration from system boot to
+  // now, instead of from app startup to now.
+  // This should be carefully changed eventually.
   return HighResTimeStamp::now();
 }
 
+HighResDuration NativePerformance::timeOrigin(jsi::Runtime& /*rt*/) {
+  // This is not spec-compliant, as this is an approximation from Unix epoch to
+  // system boot, instead of a precise duration from Unix epoch to app startup.
+  return HighResTimeStamp::unsafeOriginFromUnixTimeStamp();
+}
+
 void NativePerformance::reportMark(
     jsi::Runtime& rt,
     const std::string& name,

packages/react-native/ReactCommon/react/nativemodule/webperformance/NativePerformance.h

@@ -88,6 +88,9 @@ class NativePerformance : public NativePerformanceCxxSpec<NativePerformance> {
   // https://www.w3.org/TR/hr-time-3/#now-method
   HighResTimeStamp now(jsi::Runtime& rt);
 
+  // https://www.w3.org/TR/hr-time-3/#timeorigin-attribute
+  HighResDuration timeOrigin(jsi::Runtime& rt);
+
 #pragma mark - User Timing Level 3 functions (https://w3c.github.io/user-timing/)
 
   void reportMark(

packages/react-native/ReactCommon/react/nativemodule/webperformance/React-webperformancenativemodule.podspec

@@ -0,0 +1,58 @@
+# 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.
+
+require "json"
+
+package = JSON.parse(File.read(File.join(__dir__, "..", "..", "..", "..", "package.json")))
+version = package['version']
+
+source = { :git => 'https://github.com/facebook/react-native.git' }
+if version == '1000.0.0'
+  # This is an unpublished version, use the latest commit hash of the react-native repo, which we’re presumably in.
+  source[:commit] = `git rev-parse HEAD`.strip if system("git rev-parse --git-dir > /dev/null 2>&1")
+else
+  source[:tag] = "v#{version}"
+end
+
+header_search_paths = []
+
+if ENV['USE_FRAMEWORKS']
+  header_search_paths << "\"$(PODS_TARGET_SRCROOT)/../../..\"" # this is needed to allow the module access its own files
+end
+
+Pod::Spec.new do |s|
+  s.name                   = "React-webperformancenativemodule"
+  s.version                = version
+  s.summary                = "React Native idle callbacks native module"
+  s.homepage               = "https://reactnative.dev/"
+  s.license                = package["license"]
+  s.author                 = "Meta Platforms, Inc. and its affiliates"
+  s.platforms              = min_supported_versions
+  s.source                 = source
+  s.source_files           = podspec_sources("*.{cpp,h}", "*.h")
+  s.header_dir             = "react/nativemodule/webperformance"
+  s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
+                               "HEADER_SEARCH_PATHS" => header_search_paths.join(' '),
+                               "OTHER_CFLAGS" => "$(inherited)",
+                               "DEFINES_MODULE" => "YES" }
+
+  if ENV['USE_FRAMEWORKS']
+    s.module_name            = "webperformancenativemodule"
+    s.header_mappings_dir  = "../.."
+  end
+
+  s.dependency "React-jsi"
+  s.dependency "React-jsiexecutor"
+
+  depend_on_js_engine(s)
+  add_rn_third_party_dependencies(s)
+  add_rncore_dependency(s)
+
+  s.dependency "ReactCommon/turbomodule/core"
+  add_dependency(s, "React-RCTFBReactNativeSpec")
+  add_dependency(s, "React-performancetimeline")
+  add_dependency(s, "React-runtimeexecutor", :additional_framework_paths => ["platform/ios"])
+
+end

packages/react-native/ReactCommon/react/networking/CMakeLists.txt

@@ -0,0 +1,21 @@
+# 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.
+
+cmake_minimum_required(VERSION 3.13)
+set(CMAKE_VERBOSE_MAKEFILE on)
+
+include(${REACT_COMMON_DIR}/cmake-utils/react-native-flags.cmake)
+
+file(GLOB react_networking_SRC CONFIGURE_DEPENDS *.cpp)
+add_library(react_networking OBJECT ${react_networking_SRC})
+
+target_compile_reactnative_options(react_networking PRIVATE)
+target_compile_options(react_networking PRIVATE -Wpedantic)
+
+target_include_directories(react_networking PUBLIC ${REACT_COMMON_DIR})
+target_link_libraries(react_networking
+        folly_runtime
+        react_performance_timeline
+        react_timing)

packages/react-native/ReactCommon/react/networking/NetworkReporter.cpp

@@ -0,0 +1,192 @@
+/*
+ * 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 "NetworkReporter.h"
+
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+#include "jsinspector-modern/network/NetworkHandler.h"
+#endif
+#include <react/featureflags/ReactNativeFeatureFlags.h>
+#include <react/performance/timeline/PerformanceEntryReporter.h>
+
+namespace facebook::react {
+
+NetworkReporter& NetworkReporter::getInstance() {
+  static NetworkReporter instance;
+  return instance;
+}
+
+bool NetworkReporter::isDebuggingEnabled() const {
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  return jsinspector_modern::NetworkHandler::getInstance().isEnabled();
+#else
+  return false;
+#endif
+}
+
+void NetworkReporter::reportRequestStart(
+    const std::string& requestId,
+    const RequestInfo& requestInfo,
+    int encodedDataLength,
+    const std::optional<ResponseInfo>& redirectResponse) {
+  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
+    auto now = HighResTimeStamp::now();
+
+    // All builds: Annotate PerformanceResourceTiming metadata
+    {
+      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
+      perfTimingsBuffer_.emplace(
+          requestId,
+          ResourceTimingData{
+              .url = requestInfo.url,
+              .fetchStart = now,
+              .requestStart = now,
+          });
+    }
+  }
+
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: CDP event handling
+  jsinspector_modern::NetworkHandler::getInstance().onRequestWillBeSent(
+      requestId,
+      {
+          .url = requestInfo.url,
+          .method = requestInfo.httpMethod,
+          .headers = requestInfo.headers,
+          .postData = requestInfo.httpBody,
+      },
+      redirectResponse.has_value()
+          ? std::optional<jsinspector_modern::cdp::network::Response>(
+                jsinspector_modern::cdp::network::Response::fromInputParams(
+                    redirectResponse->url,
+                    redirectResponse->statusCode,
+                    redirectResponse->headers,
+                    encodedDataLength))
+          : std::nullopt);
+#endif
+}
+
+void NetworkReporter::reportConnectionTiming(
+    const std::string& requestId,
+    const std::optional<Headers>& headers) {
+  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
+    auto now = HighResTimeStamp::now();
+
+    // All builds: Annotate PerformanceResourceTiming metadata
+    {
+      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
+      auto it = perfTimingsBuffer_.find(requestId);
+      if (it != perfTimingsBuffer_.end()) {
+        it->second.connectStart = now;
+      }
+    }
+  }
+
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: CDP event handling
+  jsinspector_modern::NetworkHandler::getInstance()
+      .onRequestWillBeSentExtraInfo(requestId, headers.value_or(Headers{}));
+#endif
+}
+
+void NetworkReporter::reportResponseStart(
+    const std::string& requestId,
+    const ResponseInfo& responseInfo,
+    int encodedDataLength) {
+  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
+    auto now = HighResTimeStamp::now();
+
+    // All builds: Annotate PerformanceResourceTiming metadata
+    {
+      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
+      auto it = perfTimingsBuffer_.find(requestId);
+      if (it != perfTimingsBuffer_.end()) {
+        it->second.connectEnd = now;
+        it->second.responseStart = now;
+        it->second.responseStatus = responseInfo.statusCode;
+      }
+    }
+  }
+
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: CDP event handling
+  jsinspector_modern::NetworkHandler::getInstance().onResponseReceived(
+      requestId,
+      jsinspector_modern::cdp::network::Response::fromInputParams(
+          responseInfo.url,
+          responseInfo.statusCode,
+          responseInfo.headers,
+          encodedDataLength));
+#endif
+}
+
+void NetworkReporter::reportDataReceived(
+    const std::string& requestId,
+    int dataLength,
+    const std::optional<int>& encodedDataLength) {
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: CDP event handling
+  jsinspector_modern::NetworkHandler::getInstance().onDataReceived(
+      requestId, dataLength, encodedDataLength.value_or(dataLength));
+#endif
+}
+
+void NetworkReporter::reportResponseEnd(
+    const std::string& requestId,
+    int encodedDataLength) {
+  if (ReactNativeFeatureFlags::enableResourceTimingAPI()) {
+    auto now = HighResTimeStamp::now();
+
+    // All builds: Report PerformanceResourceTiming event
+    {
+      std::lock_guard<std::mutex> lock(perfTimingsMutex_);
+      auto it = perfTimingsBuffer_.find(requestId);
+      if (it != perfTimingsBuffer_.end()) {
+        auto& eventData = it->second;
+        PerformanceEntryReporter::getInstance()->reportResourceTiming(
+            eventData.url,
+            eventData.fetchStart,
+            eventData.requestStart,
+            eventData.connectStart.value_or(now),
+            eventData.connectEnd.value_or(now),
+            eventData.responseStart.value_or(now),
+            now,
+            eventData.responseStatus);
+        perfTimingsBuffer_.erase(requestId);
+      }
+    }
+  }
+
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: CDP event handling
+  jsinspector_modern::NetworkHandler::getInstance().onLoadingFinished(
+      requestId, encodedDataLength);
+#endif
+}
+
+void NetworkReporter::reportRequestFailed(
+    const std::string& requestId,
+    bool cancelled) const {
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: CDP event handling
+  jsinspector_modern::NetworkHandler::getInstance().onLoadingFailed(
+      requestId, cancelled);
+#endif
+}
+
+void NetworkReporter::storeResponseBody(
+    const std::string& requestId,
+    std::string_view body,
+    bool base64Encoded) {
+#ifdef REACT_NATIVE_DEBUGGER_ENABLED
+  // Debug build: Store fetched response body for later CDP retrieval
+  jsinspector_modern::NetworkHandler::getInstance().storeResponseBody(
+      requestId, body, base64Encoded);
+#endif
+}
+
+} // namespace facebook::react

packages/react-native/ReactCommon/react/networking/NetworkReporter.h

@@ -7,27 +7,16 @@
 
 #pragma once
 
-#include "BoundedRequestBuffer.h"
 #include "NetworkTypes.h"
 
 #include <folly/dynamic.h>
 #include <react/timing/primitives.h>
 
-#include <atomic>
-#include <functional>
 #include <mutex>
 #include <string>
-#include <tuple>
 #include <unordered_map>
 
-namespace facebook::react::jsinspector_modern {
-
-/**
- * A callback that can be used to send debugger messages (method responses and
- * events) to the frontend. The message must be a JSON-encoded string.
- * The callback may be called from any thread.
- */
-using FrontendChannel = std::function<void(std::string_view messageJson)>;
+namespace facebook::react {
 
 /**
  * Container for static network event metadata aligning with the
@@ -57,34 +46,10 @@ class NetworkReporter {
  public:
   static NetworkReporter& getInstance();
 
-  /**
-   * Set the channel used to send CDP events to the frontend. This should be
-   * supplied before calling `enableDebugging`.
-   */
-  void setFrontendChannel(FrontendChannel frontendChannel);
-
-  /**
-   * Enable network tracking over CDP. Once enabled, network events will be
-   * sent to the debugger client. Returns `false` if already enabled.
-   *
-   * Corresponds to `Network.enable` in CDP.
-   */
-  bool enableDebugging();
-
-  /**
-   * Disable network tracking over CDP, preventing network events from being
-   * sent to the debugger client. Returns `false` if not initially enabled.
-   *
-   * Corresponds to `Network.disable` in CDP.
-   */
-  bool disableDebugging();
-
   /**
    * Returns whether network tracking over CDP is currently enabled.
    */
-  inline bool isDebuggingEnabled() const {
-    return debuggingEnabled_.load(std::memory_order_acquire);
-  }
+  bool isDebuggingEnabled() const;
 
   /**
    * Report a network request that is about to be sent.
@@ -174,38 +139,14 @@ class NetworkReporter {
       std::string_view body,
       bool base64Encoded);
 
-  /**
-   * Retrieve a stored response body for a given request ID.
-   *
-   * \returns An optional tuple of [responseBody, base64Encoded]. Returns
-   * nullopt if no entry is found in the buffer.
-   */
-  std::optional<std::tuple<std::string, bool>> getResponseBody(
-      const std::string& requestId);
-
  private:
   NetworkReporter() = default;
   NetworkReporter(const NetworkReporter&) = delete;
   NetworkReporter& operator=(const NetworkReporter&) = delete;
   ~NetworkReporter() = default;
 
-  std::atomic<bool> debuggingEnabled_{false};
-
-  inline bool isDebuggingEnabledNoSync() const {
-    return debuggingEnabled_.load(std::memory_order_relaxed);
-  }
-
-  FrontendChannel frontendChannel_;
-
   std::unordered_map<std::string, ResourceTimingData> perfTimingsBuffer_{};
   std::mutex perfTimingsMutex_;
-
-  // Only populated when CDP debugging is enabled.
-  std::map<std::string, std::string> resourceTypeMap_{};
-
-  // Only populated when CDP debugging is enabled.
-  BoundedRequestBuffer requestBodyBuffer_{};
-  std::mutex requestBodyMutex_;
 };
 
-} // namespace facebook::react::jsinspector_modern
+} // namespace facebook::react

packages/react-native/ReactCommon/react/networking/NetworkTypes.h

@@ -13,7 +13,7 @@
 
 // Defines generic input object types for NetworkReporter.
 
-namespace facebook::react::jsinspector_modern {
+namespace facebook::react {
 
 /**
  * A collection of parsed HTTP headers.
@@ -39,4 +39,4 @@ struct ResponseInfo {
   std::optional<Headers> headers;
 };
 
-} // namespace facebook::react::jsinspector_modern
+} // namespace facebook::react

packages/react-native/ReactCommon/react/networking/React-networking.podspec

@@ -0,0 +1,51 @@
+# 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.
+
+require "json"
+
+package = JSON.parse(File.read(File.join(__dir__, "..", "..", "..", "package.json")))
+version = package['version']
+
+source = { :git => 'https://github.com/facebook/react-native.git' }
+if version == '1000.0.0'
+  # This is an unpublished version, use the latest commit hash of the react-native repo, which we’re presumably in.
+  source[:commit] = `git rev-parse HEAD`.strip if system("git rev-parse --git-dir > /dev/null 2>&1")
+else
+  source[:tag] = "v#{version}"
+end
+
+header_search_paths = []
+
+if ENV['USE_FRAMEWORKS']
+  header_search_paths << "\"$(PODS_TARGET_SRCROOT)/../..\"" # this is needed to allow the feature flags access its own files
+end
+
+Pod::Spec.new do |s|
+  s.name                   = "React-networking"
+  s.version                = version
+  s.summary                = "Common networking modules for React Native"
+  s.homepage               = "https://reactnative.dev/"
+  s.license                = package["license"]
+  s.author                 = "Meta Platforms, Inc. and its affiliates"
+  s.platforms              = min_supported_versions
+  s.source                 = source
+  s.source_files           = podspec_sources("*.{cpp,h}", "*.h")
+  s.header_dir             = "react/networking"
+  s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
+                               "HEADER_SEARCH_PATHS" => header_search_paths.join(' '),
+                               "DEFINES_MODULE" => "YES" }
+
+  if ENV['USE_FRAMEWORKS'] && ReactNativeCoreUtils.build_rncore_from_source()
+    s.module_name            = "React_networking"
+    s.header_mappings_dir  = "../.."
+  end
+  add_dependency(s, "React-featureflags")
+  add_dependency(s, "React-jsinspectornetwork", :framework_name => 'jsinspector_modernnetwork')
+  s.dependency "React-performancetimeline"
+  s.dependency "React-timing"
+
+  add_rn_third_party_dependencies(s)
+  add_rncore_dependency(s)
+end

packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.cpp

@@ -742,7 +742,8 @@ folly::dynamic NativeAnimatedNodesManager::managedProps(
     if (const auto node = getAnimatedNode<PropsAnimatedNode>(iter->second)) {
       return node->props();
     }
-  } else {
+  } else if (!ReactNativeFeatureFlags::
+                 overrideBySynchronousMountPropsAtMountingAndroid()) {
     std::lock_guard<std::mutex> lockUnsyncedDirectViewProps(
         unsyncedDirectViewPropsMutex_);
     if (auto it = unsyncedDirectViewProps_.find(tag);
@@ -761,7 +762,8 @@ bool NativeAnimatedNodesManager::hasManagedProps() const noexcept {
       return true;
     }
   }
-  {
+  if (!ReactNativeFeatureFlags::
+          overrideBySynchronousMountPropsAtMountingAndroid()) {
     std::lock_guard<std::mutex> lock(unsyncedDirectViewPropsMutex_);
     if (!unsyncedDirectViewProps_.empty()) {
       return true;
@@ -771,10 +773,13 @@ bool NativeAnimatedNodesManager::hasManagedProps() const noexcept {
 }
 
 void NativeAnimatedNodesManager::onManagedPropsRemoved(Tag tag) noexcept {
-  std::lock_guard<std::mutex> lock(unsyncedDirectViewPropsMutex_);
-  if (auto iter = unsyncedDirectViewProps_.find(tag);
-      iter != unsyncedDirectViewProps_.end()) {
-    unsyncedDirectViewProps_.erase(iter);
+  if (!ReactNativeFeatureFlags::
+          overrideBySynchronousMountPropsAtMountingAndroid()) {
+    std::lock_guard<std::mutex> lock(unsyncedDirectViewPropsMutex_);
+    if (auto iter = unsyncedDirectViewProps_.find(tag);
+        iter != unsyncedDirectViewProps_.end()) {
+      unsyncedDirectViewProps_.erase(iter);
+    }
   }
 }
 
@@ -828,7 +833,8 @@ void NativeAnimatedNodesManager::schedulePropsCommit(
     mergeObjects(updateViewPropsDirect_[viewTag], props);
   } else if (!layoutStyleUpdated && directManipulationCallback_ != nullptr) {
     mergeObjects(updateViewPropsDirect_[viewTag], props);
-    {
+    if (!ReactNativeFeatureFlags::
+            overrideBySynchronousMountPropsAtMountingAndroid()) {
       std::lock_guard<std::mutex> lock(unsyncedDirectViewPropsMutex_);
       mergeObjects(unsyncedDirectViewProps_[viewTag], props);
     }

packages/react-native/ReactCommon/react/renderer/attributedstring/conversions.h

@@ -402,79 +402,79 @@ inline void fromRawValue(
 inline std::string toString(const FontVariant& fontVariant) {
   auto result = std::string{};
   auto separator = std::string{", "};
-  if ((int)fontVariant & (int)FontVariant::SmallCaps) {
+  if (((int)fontVariant & (int)FontVariant::SmallCaps) != 0) {
     result += "small-caps" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::OldstyleNums) {
+  if (((int)fontVariant & (int)FontVariant::OldstyleNums) != 0) {
     result += "oldstyle-nums" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::LiningNums) {
+  if (((int)fontVariant & (int)FontVariant::LiningNums) != 0) {
     result += "lining-nums" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::TabularNums) {
+  if (((int)fontVariant & (int)FontVariant::TabularNums) != 0) {
     result += "tabular-nums" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::ProportionalNums) {
+  if (((int)fontVariant & (int)FontVariant::ProportionalNums) != 0) {
     result += "proportional-nums" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticOne) {
+  if (((int)fontVariant & (int)FontVariant::StylisticOne) != 0) {
     result += "stylistic-one" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticTwo) {
+  if (((int)fontVariant & (int)FontVariant::StylisticTwo) != 0) {
     result += "stylistic-two" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticThree) {
+  if (((int)fontVariant & (int)FontVariant::StylisticThree) != 0) {
     result += "stylistic-three" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticFour) {
+  if (((int)fontVariant & (int)FontVariant::StylisticFour) != 0) {
     result += "stylistic-four" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticFive) {
+  if (((int)fontVariant & (int)FontVariant::StylisticFive) != 0) {
     result += "stylistic-five" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticSix) {
+  if (((int)fontVariant & (int)FontVariant::StylisticSix) != 0) {
     result += "stylistic-six" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticSeven) {
+  if (((int)fontVariant & (int)FontVariant::StylisticSeven) != 0) {
     result += "stylistic-seven" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticEight) {
+  if (((int)fontVariant & (int)FontVariant::StylisticEight) != 0) {
     result += "stylistic-eight" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticNine) {
+  if (((int)fontVariant & (int)FontVariant::StylisticNine) != 0) {
     result += "stylistic-nine" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticTen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticTen) != 0) {
     result += "stylistic-ten" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticEleven) {
+  if (((int)fontVariant & (int)FontVariant::StylisticEleven) != 0) {
     result += "stylistic-eleven" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticTwelve) {
+  if (((int)fontVariant & (int)FontVariant::StylisticTwelve) != 0) {
     result += "stylistic-twelve" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticThirteen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticThirteen) != 0) {
     result += "stylistic-thirteen" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticFourteen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticFourteen) != 0) {
     result += "stylistic-fourteen" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticFifteen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticFifteen) != 0) {
     result += "stylistic-fifteen" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticSixteen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticSixteen) != 0) {
     result += "stylistic-sixteen" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticSeventeen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticSeventeen) != 0) {
     result += "stylistic-seventeen" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticEighteen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticEighteen) != 0) {
     result += "stylistic-eighteen" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticNineteen) {
+  if (((int)fontVariant & (int)FontVariant::StylisticNineteen) != 0) {
     result += "stylistic-nineteen" + separator;
   }
-  if ((int)fontVariant & (int)FontVariant::StylisticTwenty) {
+  if (((int)fontVariant & (int)FontVariant::StylisticTwenty) != 0) {
     result += "stylistic-twenty" + separator;
   }
 

packages/react-native/ReactCommon/react/renderer/components/legacyviewmanagerinterop/LegacyViewManagerInteropComponentDescriptor.mm

@@ -63,13 +63,13 @@ static Class getViewManagerFromComponentName(const std::string &componentName)
   // 1. Try to get the manager with the RCT prefix.
   auto rctViewManagerName = "RCT" + viewManagerName;
   Class viewManagerClass = NSClassFromString(RCTNSStringFromString(rctViewManagerName));
-  if (viewManagerClass) {
+  if (viewManagerClass != nullptr) {
     return viewManagerClass;
   }
 
   // 2. Try to get the manager without the prefix.
   viewManagerClass = NSClassFromString(RCTNSStringFromString(viewManagerName));
-  if (viewManagerClass) {
+  if (viewManagerClass != nullptr) {
     return viewManagerClass;
   }
 

packages/react-native/ReactCommon/react/renderer/components/textinput/platform/android/react/renderer/components/androidtextinput/AndroidTextInputComponentDescriptor.h

@@ -54,7 +54,7 @@ class AndroidTextInputComponentDescriptor final
               ->getMethod<jboolean(jint, jfloatArray)>("getThemeData");
 
       if (getThemeData(
-              fabricUIManager, surfaceId, defaultTextInputPaddingArray)) {
+              fabricUIManager, surfaceId, defaultTextInputPaddingArray) != 0u) {
         jfloat* defaultTextInputPadding =
             env->GetFloatArrayElements(defaultTextInputPaddingArray, nullptr);
         theme.start = defaultTextInputPadding[0];

packages/react-native/ReactCommon/react/renderer/components/view/platform/android/react/renderer/components/view/HostPlatformViewProps.cpp

@@ -310,7 +310,7 @@ static void updateBorderColorPropValue(
     const std::optional<SharedColor>& newColor,
     const std::optional<SharedColor>& oldColor) {
   if (newColor != oldColor) {
-    result[propName] = *newColor.value_or(SharedColor());
+    result[propName] = newColor.has_value() ? *newColor.value() : NULL;
   }
 }