Add support for feature flags without native implementation (facebook…

…#47059) Summary: Changelog: [internal] This adds a new configuration for feature flags to preserve their definition only in JavaScript and skip their native API and implementations. This is useful to preserve the API in JavaScript when JavaScript changes progress faster than native changes. Reviewed By: sammy-SC Differential Revision: D64464779
rubennorte · Oct 17, 2024 · 953407a · 953407a
1 parent 01e210f
commit 953407a
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Showing 8 changed files with 93 additions and 29 deletions.
diff --git a/...eact-native/ReactCommon/react/nativemodule/featureflags/NativeReactNativeFeatureFlags.cpp b/...eact-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<<81047b339ef89dfdfa10b58e22d9407d>>
+ * @generated SignedSource<<61c80a52ec4c2cf0904bb17c8f479f9d>>
  */
 
 /**
@@ -42,6 +42,13 @@ bool NativeReactNativeFeatureFlags::commonTestFlag(
   return ReactNativeFeatureFlags::commonTestFlag();
 }
 
+bool NativeReactNativeFeatureFlags::commonTestFlagWithoutNativeImplementation(
+    jsi::Runtime& /*runtime*/) {
+  // This flag is configured with `skipNativeAPI: true`.
+  // TODO(T204838867): Implement support for optional methods in C++ TM codegen and remove the method definition altogether.
+  return false;
+}
+
 bool NativeReactNativeFeatureFlags::allowRecursiveCommitsWithSynchronousMountOnAndroid(
     jsi::Runtime& /*runtime*/) {
   return ReactNativeFeatureFlags::allowRecursiveCommitsWithSynchronousMountOnAndroid();

diff --git a/.../react-native/ReactCommon/react/nativemodule/featureflags/NativeReactNativeFeatureFlags.h b/.../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<<8260155b1822cf4906660d3ad9b298a4>>
+ * @generated SignedSource<<68423ab013e1357ec176da0fbef4f7e8>>
  */
 
 /**
@@ -37,6 +37,8 @@ class NativeReactNativeFeatureFlags
 
   bool commonTestFlag(jsi::Runtime& runtime);
 
+  bool commonTestFlagWithoutNativeImplementation(jsi::Runtime& runtime);
+
   bool allowRecursiveCommitsWithSynchronousMountOnAndroid(jsi::Runtime& runtime);
 
   bool batchRenderingUpdatesInEventLoop(jsi::Runtime& runtime);

diff --git a/packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js b/packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js
@@ -30,6 +30,15 @@ const testDefinitions: FeatureFlagDefinitions = {
         purpose: 'operational',
       },
     },
+    commonTestFlagWithoutNativeImplementation: {
+      defaultValue: false,
+      metadata: {
+        description:
+          'Common flag for testing (without native implementation). Do NOT modify.',
+        purpose: 'operational',
+      },
+      skipNativeAPI: true,
+    },
   },
   jsOnly: {
     jsOnlyTestFlag: {

diff --git a/packages/react-native/scripts/featureflags/generateFiles.js b/packages/react-native/scripts/featureflags/generateFiles.js
@@ -28,11 +28,31 @@ export default function generateFiles(
 
   const jsModules = generateJavaScriptModules(generatorConfig);
 
-  const commonCxxModules = generateCommonCxxModules(generatorConfig);
+  const generatorConfigWithDefinitionsForNative = {
+    ...generatorConfig,
+    featureFlagDefinitions: {
+      ...generatorConfig.featureFlagDefinitions,
+      common: Object.fromEntries(
+        Object.entries(generatorConfig.featureFlagDefinitions.common).filter(
+          ([_, definition]) => !definition.skipNativeAPI,
+        ),
+      ),
+    },
+  };
 
-  const androidModules = generateAndroidModules(generatorConfig);
+  const commonCxxModules = generateCommonCxxModules(
+    generatorConfigWithDefinitionsForNative,
+  );
 
-  const generatedFiles = {...jsModules, ...commonCxxModules, ...androidModules};
+  const androidModules = generateAndroidModules(
+    generatorConfigWithDefinitionsForNative,
+  );
+
+  const generatedFiles = {
+    ...jsModules,
+    ...commonCxxModules,
+    ...androidModules,
+  };
 
   if (generatorOptions.verifyUnchanged) {
     const existingModules: {[string]: string} = {};

diff --git a/...ct-native/scripts/featureflags/templates/js/NativeReactNativeFeatureFlags.cpp-template.js b/...ct-native/scripts/featureflags/templates/js/NativeReactNativeFeatureFlags.cpp-template.js
@@ -46,11 +46,19 @@ NativeReactNativeFeatureFlags::NativeReactNativeFeatureFlags(
     : NativeReactNativeFeatureFlagsCxxSpec(std::move(jsInvoker)) {}
 
 ${Object.entries(definitions.common)
-  .map(
-    ([flagName, flagConfig]) =>
-      `${getCxxTypeFromDefaultValue(
-        flagConfig.defaultValue,
-      )} NativeReactNativeFeatureFlags::${flagName}(
+  .map(([flagName, flagConfig]) =>
+    flagConfig.skipNativeAPI
+      ? `${getCxxTypeFromDefaultValue(
+          flagConfig.defaultValue,
+        )} NativeReactNativeFeatureFlags::${flagName}(
+    jsi::Runtime& /*runtime*/) {
+  // This flag is configured with \`skipNativeAPI: true\`.
+  // TODO(T204838867): Implement support for optional methods in C++ TM codegen and remove the method definition altogether.
+  return ${JSON.stringify(flagConfig.defaultValue)};
+}`
+      : `${getCxxTypeFromDefaultValue(
+          flagConfig.defaultValue,
+        )} NativeReactNativeFeatureFlags::${flagName}(
     jsi::Runtime& /*runtime*/) {
   return ReactNativeFeatureFlags::${flagName}();
 }`,

diff --git a/packages/react-native/scripts/featureflags/types.js b/packages/react-native/scripts/featureflags/types.js
@@ -11,30 +11,42 @@
 export type FeatureFlagValue = boolean | number | string;
 
 export type FeatureFlagDefinitions = {
-  common: FeatureFlagList,
-  jsOnly: FeatureFlagList,
+  common: CommonFeatureFlagList,
+  jsOnly: JsOnlyFeatureFlagList,
 };
 
-type FeatureFlagList = {
+type CommonFeatureFlagList = {
   [flagName: string]: {
     defaultValue: FeatureFlagValue,
-    metadata:
-      | {
-          purpose: 'experimentation',
-          /**
-           * Aproximate date when the flag was added.
-           * Used to help prioritize feature flags that need to be cleaned up.
-           */
-          dateAdded: string,
-          description: string,
-        }
-      | {
-          purpose: 'operational' | 'release',
-          description: string,
-        },
+    metadata: FeatureFlagMetadata,
+    // Indicates if this API should only be defined in JavaScript, only to
+    // preserve backwards compatibility with existing native code temporarily.
+    skipNativeAPI?: true,
   },
 };
 
+type JsOnlyFeatureFlagList = {
+  [flagName: string]: {
+    defaultValue: FeatureFlagValue,
+    metadata: FeatureFlagMetadata,
+  },
+};
+
+type FeatureFlagMetadata =
+  | {
+      purpose: 'experimentation',
+      /**
+       * Aproximate date when the flag was added.
+       * Used to help prioritize feature flags that need to be cleaned up.
+       */
+      dateAdded: string,
+      description: string,
+    }
+  | {
+      purpose: 'operational' | 'release',
+      description: string,
+    };
+
 export type GeneratorConfig = {
   featureFlagDefinitions: FeatureFlagDefinitions,
   jsPath: string,

diff --git a/packages/react-native/src/private/featureflags/ReactNativeFeatureFlags.js b/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<<5f8a62b797980987ce7f415fa00c0965>>
+ * @generated SignedSource<<b86924d0e998d2f9656f91ac7459bc3c>>
  * @flow strict
  */
 
@@ -51,6 +51,7 @@ export type ReactNativeFeatureFlagsJsOnlyOverrides = OverridesFor<ReactNativeFea
 export type ReactNativeFeatureFlags = {
   ...ReactNativeFeatureFlagsJsOnly,
   commonTestFlag: Getter<boolean>,
+  commonTestFlagWithoutNativeImplementation: Getter<boolean>,
   allowRecursiveCommitsWithSynchronousMountOnAndroid: Getter<boolean>,
   batchRenderingUpdatesInEventLoop: Getter<boolean>,
   completeReactInstanceCreationOnBgThreadOnAndroid: Getter<boolean>,
@@ -188,6 +189,10 @@ export const useRefsForTextInputState: Getter<boolean> = createJavaScriptFlagGet
  * Common flag for testing. Do NOT modify.
  */
 export const commonTestFlag: Getter<boolean> = createNativeFlagGetter('commonTestFlag', false);
+/**
+ * Common flag for testing (without native implementation). Do NOT modify.
+ */
+export const commonTestFlagWithoutNativeImplementation: Getter<boolean> = createNativeFlagGetter('commonTestFlagWithoutNativeImplementation', false);
 /**
  * Adds support for recursively processing commits that mount synchronously (Android only).
  */

diff --git a/packages/react-native/src/private/featureflags/specs/NativeReactNativeFeatureFlags.js b/packages/react-native/src/private/featureflags/specs/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<<2dea79097b1952f97d9e5dda86a38e58>>
+ * @generated SignedSource<<ab8cd7856e973a389fc400ed35e21dd8>>
  * @flow strict
  */
 
@@ -24,6 +24,7 @@ import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboMod
 
 export interface Spec extends TurboModule {
   +commonTestFlag?: () => boolean;
+  +commonTestFlagWithoutNativeImplementation?: () => boolean;
   +allowRecursiveCommitsWithSynchronousMountOnAndroid?: () => boolean;
   +batchRenderingUpdatesInEventLoop?: () => boolean;
   +completeReactInstanceCreationOnBgThreadOnAndroid?: () => boolean;