Move feature flag definitions to JS file instead of JSON (#42815)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/42815

Feature flags were originally defined in a JSON file for easier interoperability but we're only using the definitions in JS anyway, so having the definitions in a JS file is more flexible (e.g.: adding comments).

Changelog: [internal]

Reviewed By: huntie

Differential Revision: D53351483

fbshipit-source-id: 23fe0a3898b4facf2f2cf9645f78c45d78937f31

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<f4268973a38ba972e68474cc31bab5a7>>
+ * @generated SignedSource<<f5d5bb65068bb515d33da8bff665dfd2>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<5b653e8a53f557ffc0f46b3e81e99bed>>
+ * @generated SignedSource<<d4ece56f9329579346fbfe08f7681632>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<47be3dbe5558f720a6c61742f2c63bf8>>
+ * @generated SignedSource<<41a2646126f7f448be8c8397b1698a4a>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<70c19d5bb1e0c09f52b89b4bb3645b9d>>
+ * @generated SignedSource<<fc15c71267f1bf2f65c4f3877599c4c7>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<7ba0cb94c10989838250252fa06768a0>>
+ * @generated SignedSource<<77fc4d6577fc0e2e9a0500cc762bba77>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<b0f60718eedab65390ebfb7864a10a27>>
+ * @generated SignedSource<<49a63388fa661d81b9cec735ac705bd0>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<dab6daf99192f983b7c8ad7633b43a33>>
+ * @generated SignedSource<<e570b62b4a208b2526169361c3a6be6a>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c2a4da926b870497f76c03c8f97199e2>>
+ * @generated SignedSource<<356873b4021fcfe9a2afa79417813975>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<feb0342515d10b3519675cd91efa65dc>>
+ * @generated SignedSource<<40972962362d704915fe7c851ef6a545>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<879b0c096c4a2e9692a5e133bdfd8809>>
+ * @generated SignedSource<<f8b92fe90e60292ea2f88a4659e3fd50>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<6ccf42209dea35cd5c6ac9eb882c2ef7>>
+ * @generated SignedSource<<c43f5dfe4a0e12da0595071319c91e63>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<252f46e2c95e08d1180f656c870087b7>>
+ * @generated SignedSource<<c0d0f4bb2eb2dbf385d56f58444fb16a>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<ef51a5a7152e6f4fe0556b17aec2c0c2>>
+ * @generated SignedSource<<0f2ef778c97b1928fde0245008015227>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<b61bc487a077e9e1dc6ab2b176fd72cb>>
+ * @generated SignedSource<<4de1ed8503548f440c1a0e4f903c80c7>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<b39abca7a1fcce7ae124565cfc619d04>>
+ * @generated SignedSource<<f97b884f948b3ebf00df11b30cfe3ea4>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<72abac7cc75e65bf1ded596033637050>>
+ * @generated SignedSource<<f2bbc5a034e11e11190da7f5ea289b7c>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<64ea070fb82bd703eb617dcf64c6a7d1>>
+ * @generated SignedSource<<19dba0cacd4599408a2adeeeb1dce6f2>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

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

@@ -4,14 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<994628655312f57c8ab774e9f119eb18>>
+ * @generated SignedSource<<4ce1b29660d13ea8dfe09777d9907f3f>>
  */
 
 /**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

packages/react-native/scripts/featureflags/README.md

@@ -11,39 +11,25 @@ everywhere.
 
 ## Definition
 
-The source of truth for the definition of the flags is the file `ReactNativeFeatureFlags.json`
-in this directory. That JSON file should have the following structure:
+The source of truth for the definition of the flags is the file
+`ReactNativeFeatureFlags.config.js` in this directory.
 
-```flow
-type Config = {
-  common: FeatureFlagsList,
-  jsOnly: FeatureFlagsList,
-};
-
-type FeatureFlagsList = {
-  [flagName: string]: {
-    description: string,
-    defaultValue: boolean | number | string,
-  },
-};
-```
-
-Example:
-```json
-{
-  "common": {
-    "enableMicrotasks": {
-      "description": "Enable the use of microtasks in the JS runtime.",
-      "defaultValue": false
+Example contents:
+```javascript
+module.exports = {
+  common: {
+    enableMicrotasks: {
+      description: 'Enable the use of microtasks in the JS runtime.',
+      defaultValue: false
     }
   },
-  "jsOnly": {
-    "enableAccessToHostTreeInFabric": {
-      "description": "Enables access to the host tree in Fabric using DOM-compatible APIs.",
-      "defaultValue": false
+  jsOnly: {
+    enableAccessToHostTreeInFabric: {
+      description: 'Enables access to the host tree in Fabric using DOM-compatible APIs.',
+      defaultValue: false
     }
   }
-}
+};
 ```
 
 After any changes to this definitions, the code that provides access to them
@@ -52,6 +38,16 @@ repository.
 
 ## Access
 
+You can access the common feature flags from anywhere in your application using
+the `ReactNativeFeatureFlags` interface (available in C++/Objective-C++,
+Kotlin/Java and JavaScript). JS-only feature flags can only be accessed from
+JavaScript.
+
+**Accessing feature flags should be considered fast for all use cases**.
+Feature flags are cached at every layer, which prevents having to go through JNI
+when accessing the values from Kotlin and through JSI when accessing the values
+from JavaScript.
+
 ### C++ / Objective-C
 
 ```c++
@@ -90,6 +86,15 @@ if (ReactNativeFeatureFlags.enableAccessToHostTreeInFabric()) {
 
 ## Customization
 
+Feature flags provide the default values defined in the configuration unless
+overrides are applied at the application level. Overrides for common feature
+flags can only be defined in native, while overrides for JS-ony flags can only
+be defined in JavaScript.
+
+Overrides must be applied before any of the available feature flags has been
+accessed. This prevents having inconsistent behavior during the lifecycle of the
+application.
+
 ### C++/Objective-C
 
 ```c++

packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js

@@ -0,0 +1,97 @@
+/**
+ * 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.
+ *
+ * @flow strict
+ * @format
+ */
+
+import type {FeatureFlagDefinitions} from './types';
+
+const definitions: FeatureFlagDefinitions = {
+  common: {
+    // This is only used in unit tests for the feature flags system.
+    commonTestFlag: {
+      description: 'Common flag for testing. Do NOT modify.',
+      defaultValue: false,
+    },
+
+    useModernRuntimeScheduler: {
+      description:
+        'When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with priorities from any thread.',
+      defaultValue: false,
+    },
+    enableMicrotasks: {
+      description:
+        'Enables the use of microtasks in Hermes (scheduling) and RuntimeScheduler (execution).',
+      defaultValue: false,
+    },
+    batchRenderingUpdatesInEventLoop: {
+      description:
+        'When enabled, the RuntimeScheduler processing the event loop will batch all rendering updates and dispatch them together at the end of each iteration of the loop.',
+      defaultValue: false,
+    },
+    enableSpannableBuildingUnification: {
+      description:
+        'Uses new, deduplicated logic for constructing Android Spannables from text fragments',
+      defaultValue: false,
+    },
+    enableCustomDrawOrderFabric: {
+      description:
+        'When enabled, Fabric will use customDrawOrder in ReactViewGroup (similar to old architecture).',
+      defaultValue: false,
+    },
+    enableFixForClippedSubviewsCrash: {
+      description:
+        'Attempt at fixing a crash related to subview clipping on Android. This is a kill switch for the fix',
+      defaultValue: false,
+    },
+  },
+
+  jsOnly: {
+    // This is only used in unit tests for the feature flags system.
+    jsOnlyTestFlag: {
+      description: 'JS-only flag for testing. Do NOT modify.',
+      defaultValue: false,
+    },
+
+    isLayoutAnimationEnabled: {
+      description:
+        'Function used to enable / disabled Layout Animations in React Native.',
+      defaultValue: true,
+    },
+    animatedShouldDebounceQueueFlush: {
+      description:
+        'Enables an experimental flush-queue debouncing in Animated.js.',
+      defaultValue: false,
+    },
+    animatedShouldUseSingleOp: {
+      description:
+        'Enables an experimental mega-operation for Animated.js that replaces many calls to native with a single call into native, to reduce JSI/JNI traffic.',
+      defaultValue: false,
+    },
+    enableAccessToHostTreeInFabric: {
+      description:
+        'Enables access to the host tree in Fabric using DOM-compatible APIs.',
+      defaultValue: false,
+    },
+    shouldUseAnimatedObjectForTransform: {
+      description:
+        'Enables use of AnimatedObject for animating transform values.',
+      defaultValue: false,
+    },
+    shouldUseSetNativePropsInFabric: {
+      description: 'Enables use of setNativeProps in JS driven animations.',
+      defaultValue: true,
+    },
+    shouldUseRemoveClippedSubviewsAsDefaultOnIOS: {
+      description:
+        'removeClippedSubviews prop will be used as the default in FlatList on iOS to match Android',
+      defaultValue: false,
+    },
+  },
+};
+
+export default definitions;

packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json

@@ -1,66 +0,0 @@
-{
-  "common": {
-    "commonTestFlag": {
-      "description": "Common flag for testing. Do NOT modify.",
-      "defaultValue": false
-    },
-    "useModernRuntimeScheduler": {
-      "description": "When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with priorities from any thread.",
-      "defaultValue": false
-    },
-    "enableMicrotasks": {
-      "description": "Enables the use of microtasks in Hermes (scheduling) and RuntimeScheduler (execution).",
-      "defaultValue": false
-    },
-    "batchRenderingUpdatesInEventLoop": {
-      "description": "When enabled, the RuntimeScheduler processing the event loop will batch all rendering updates and dispatch them together at the end of each iteration of the loop.",
-      "defaultValue": false
-    },
-    "enableSpannableBuildingUnification": {
-      "description": "Uses new, deduplicated logic for constructing Android Spannables from text fragments",
-      "defaultValue": false
-    },
-    "enableCustomDrawOrderFabric": {
-      "description": "When enabled, Fabric will use customDrawOrder in ReactViewGroup (similar to old architecture).",
-      "defaultValue": false
-    },
-    "enableFixForClippedSubviewsCrash": {
-      "description": "Attempt at fixing a crash related to subview clipping on Android. This is a kill switch for the fix",
-      "defaultValue": false
-    }
-  },
-  "jsOnly": {
-    "jsOnlyTestFlag": {
-      "description": "JS-only flag for testing. Do NOT modify.",
-      "defaultValue": false
-    },
-    "isLayoutAnimationEnabled": {
-      "description": "Function used to enable / disabled Layout Animations in React Native.",
-      "defaultValue": true
-    },
-    "animatedShouldDebounceQueueFlush": {
-      "description": "Enables an experimental flush-queue debouncing in Animated.js.",
-      "defaultValue": false
-    },
-    "animatedShouldUseSingleOp": {
-      "description": "Enables an experimental mega-operation for Animated.js that replaces many calls to native with a single call into native, to reduce JSI/JNI traffic.",
-      "defaultValue": false
-    },
-    "enableAccessToHostTreeInFabric": {
-      "description": "Enables access to the host tree in Fabric using DOM-compatible APIs.",
-      "defaultValue": false
-    },
-    "shouldUseAnimatedObjectForTransform": {
-      "description": "Enables use of AnimatedObject for animating transform values.",
-      "defaultValue": false
-    },
-    "shouldUseSetNativePropsInFabric": {
-      "description": "Enables use of setNativeProps in JS driven animations.",
-      "defaultValue": true
-    },
-    "shouldUseRemoveClippedSubviewsAsDefaultOnIOS": {
-      "description": "removeClippedSubviews prop will be used as the default in FlatList on iOS to match Android",
-      "defaultValue": false
-    }
-  }
-}

packages/react-native/scripts/featureflags/update.js

@@ -9,7 +9,7 @@
  */
 
 import generateFiles from './generateFiles';
-import fs from 'fs';
+import featureFlagDefinitions from './ReactNativeFeatureFlags.config';
 import path from 'path';
 
 const REACT_NATIVE_PACKAGE_ROOT = path.join(__dirname, '..', '..');
@@ -17,12 +17,7 @@ const REACT_NATIVE_PACKAGE_ROOT = path.join(__dirname, '..', '..');
 export default function update(verifyUnchanged: boolean): void {
   generateFiles(
     {
-      featureFlagDefinitions: JSON.parse(
-        fs.readFileSync(
-          path.join(__dirname, 'ReactNativeFeatureFlags.json'),
-          'utf8',
-        ),
-      ),
+      featureFlagDefinitions,
       jsPath: path.join(
         REACT_NATIVE_PACKAGE_ROOT,
         'src',

packages/react-native/scripts/featureflags/utils.js

@@ -44,7 +44,7 @@ export const DO_NOT_MODIFY_COMMENT = `/**
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

packages/react-native/src/private/featureflags/NativeReactNativeFeatureFlags.js

@@ -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<<2ca87dc970592f66d83f4799c4047c9b>>
+ * @generated SignedSource<<c1164fd870a4f1540d9b8c956af2b678>>
  * @flow strict-local
  */
 
@@ -12,7 +12,7 @@
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update

packages/react-native/src/private/featureflags/ReactNativeFeatureFlags.js

@@ -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<<b6bac87d45019ecb8a3ca1ff43c2f912>>
+ * @generated SignedSource<<52b25f675aa8d5ae45941f0ee951358a>>
  * @flow strict-local
  */
 
@@ -12,7 +12,7 @@
  * IMPORTANT: Do NOT modify this file directly.
  *
  * To change the definition of the flags, edit
- *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.json.
+ *   packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js.
  *
  * To regenerate this code, run the following script from the repo root:
  *   yarn featureflags-update