Turbo module: Fixes dictionary stripped out when value is null (#51103)

Summary:
Fixes https://github.com/facebook/react-native/issues/51083. Turbo stripped out the dictionary when the value is null. The old architecture transforms null to NSNull. The null seems useful in cases like #51803 for removing the storage of the key. cipolleschi can you please help to review?

## Changelog:

[IOS] [FIXED] - Turbo module: Fixes dictionary stripped out when value is null

Pull Request resolved: https://github.com/facebook/react-native/pull/51103

Test Plan: Repro please see https://github.com/facebook/react-native/issues/51083.

Reviewed By: rshest

Differential Revision: D74208525

Pulled By: javache

fbshipit-source-id: 53d630c265fba15d25309a3e1deb19dca24f298c

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<<62715a19c87a010716eb7d2e904258fa>>
+ * @generated SignedSource<<a5552614b746c732adb88a6640a7951a>>
  */
 
 /**
@@ -174,6 +174,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableMainQueueModulesOnIOS(): Boolean = accessor.enableMainQueueModulesOnIOS()
 
+  /**
+   * Enable NSNull conversion when handling module arguments on iOS
+   */
+  @JvmStatic
+  public fun enableModuleArgumentNSNullConversionIOS(): Boolean = accessor.enableModuleArgumentNSNullConversionIOS()
+
   /**
    * Parse CSS strings using the Fabric CSS parser instead of ViewConfig processing
    */

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<<53e2f9241b9b3396b1ddf5893c7f3c4e>>
+ * @generated SignedSource<<4665e190f626b377f37e14c1c19f809d>>
  */
 
 /**
@@ -44,6 +44,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var enableLayoutAnimationsOnAndroidCache: Boolean? = null
   private var enableLayoutAnimationsOnIOSCache: Boolean? = null
   private var enableMainQueueModulesOnIOSCache: Boolean? = null
+  private var enableModuleArgumentNSNullConversionIOSCache: Boolean? = null
   private var enableNativeCSSParsingCache: Boolean? = null
   private var enableNetworkEventReportingCache: Boolean? = null
   private var enableNewBackgroundAndBorderDrawablesCache: Boolean? = null
@@ -287,6 +288,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun enableModuleArgumentNSNullConversionIOS(): Boolean {
+    var cached = enableModuleArgumentNSNullConversionIOSCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableModuleArgumentNSNullConversionIOS()
+      enableModuleArgumentNSNullConversionIOSCache = cached
+    }
+    return cached
+  }
+
   override fun enableNativeCSSParsing(): Boolean {
     var cached = enableNativeCSSParsingCache
     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<<918dcdb416bb3e2e3f83cded78e06363>>
+ * @generated SignedSource<<b68166d039f6214ff09dc30a742ebbf9>>
  */
 
 /**
@@ -76,6 +76,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableMainQueueModulesOnIOS(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun enableModuleArgumentNSNullConversionIOS(): Boolean
+
   @DoNotStrip @JvmStatic public external fun enableNativeCSSParsing(): Boolean
 
   @DoNotStrip @JvmStatic public external fun enableNetworkEventReporting(): Boolean

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<<7151e167c4e45a732a341a2cfcf67b58>>
+ * @generated SignedSource<<fcee66a9800d5b3b1105df73d33feea9>>
  */
 
 /**
@@ -71,6 +71,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableMainQueueModulesOnIOS(): Boolean = false
 
+  override fun enableModuleArgumentNSNullConversionIOS(): Boolean = true
+
   override fun enableNativeCSSParsing(): Boolean = false
 
   override fun enableNetworkEventReporting(): Boolean = false

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<<d2f4ae1cd4e33cb59903c3b2c3ef0fc2>>
+ * @generated SignedSource<<ebf6d5811f40eedd906c015283f5757f>>
  */
 
 /**
@@ -48,6 +48,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var enableLayoutAnimationsOnAndroidCache: Boolean? = null
   private var enableLayoutAnimationsOnIOSCache: Boolean? = null
   private var enableMainQueueModulesOnIOSCache: Boolean? = null
+  private var enableModuleArgumentNSNullConversionIOSCache: Boolean? = null
   private var enableNativeCSSParsingCache: Boolean? = null
   private var enableNetworkEventReportingCache: Boolean? = null
   private var enableNewBackgroundAndBorderDrawablesCache: Boolean? = null
@@ -315,6 +316,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun enableModuleArgumentNSNullConversionIOS(): Boolean {
+    var cached = enableModuleArgumentNSNullConversionIOSCache
+    if (cached == null) {
+      cached = currentProvider.enableModuleArgumentNSNullConversionIOS()
+      accessedFeatureFlags.add("enableModuleArgumentNSNullConversionIOS")
+      enableModuleArgumentNSNullConversionIOSCache = cached
+    }
+    return cached
+  }
+
   override fun enableNativeCSSParsing(): Boolean {
     var cached = enableNativeCSSParsingCache
     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<<722ed5b36a043d4eadb095f092c95707>>
+ * @generated SignedSource<<1e5562ce20c0735c926c1cb029b93e18>>
  */
 
 /**
@@ -71,6 +71,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableMainQueueModulesOnIOS(): Boolean
 
+  @DoNotStrip public fun enableModuleArgumentNSNullConversionIOS(): Boolean
+
   @DoNotStrip public fun enableNativeCSSParsing(): Boolean
 
   @DoNotStrip public fun enableNetworkEventReporting(): Boolean

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<<422a5922cfe14a1c5f7c0728410dbe8a>>
+ * @generated SignedSource<<078954ede626079b7d36ab63cdbab761>>
  */
 
 /**
@@ -183,6 +183,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool enableModuleArgumentNSNullConversionIOS() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableModuleArgumentNSNullConversionIOS");
+    return method(javaProvider_);
+  }
+
   bool enableNativeCSSParsing() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableNativeCSSParsing");
@@ -463,6 +469,11 @@ bool JReactNativeFeatureFlagsCxxInterop::enableMainQueueModulesOnIOS(
   return ReactNativeFeatureFlags::enableMainQueueModulesOnIOS();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::enableModuleArgumentNSNullConversionIOS(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::enableNativeCSSParsing(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::enableNativeCSSParsing();
@@ -696,6 +707,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableMainQueueModulesOnIOS",
         JReactNativeFeatureFlagsCxxInterop::enableMainQueueModulesOnIOS),
+      makeNativeMethod(
+        "enableModuleArgumentNSNullConversionIOS",
+        JReactNativeFeatureFlagsCxxInterop::enableModuleArgumentNSNullConversionIOS),
       makeNativeMethod(
         "enableNativeCSSParsing",
         JReactNativeFeatureFlagsCxxInterop::enableNativeCSSParsing),

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<<18d7c9c2577450a0bb7e6da91b8597ed>>
+ * @generated SignedSource<<083e45ab99622254be46213ba07c586b>>
  */
 
 /**
@@ -102,6 +102,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableMainQueueModulesOnIOS(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool enableModuleArgumentNSNullConversionIOS(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool enableNativeCSSParsing(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

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<<9f34463a7cddcfd1a76631041297c4b7>>
+ * @generated SignedSource<<c099ce4bba5f6d14a83ad69a0fb3cbbf>>
  */
 
 /**
@@ -122,6 +122,10 @@ bool ReactNativeFeatureFlags::enableMainQueueModulesOnIOS() {
   return getAccessor().enableMainQueueModulesOnIOS();
 }
 
+bool ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS() {
+  return getAccessor().enableModuleArgumentNSNullConversionIOS();
+}
+
 bool ReactNativeFeatureFlags::enableNativeCSSParsing() {
   return getAccessor().enableNativeCSSParsing();
 }

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<<cb84333e310cfc1a6a77f1b376723e93>>
+ * @generated SignedSource<<ac9a0bc61f58cce6fe9d229c551dc3f7>>
  */
 
 /**
@@ -159,6 +159,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableMainQueueModulesOnIOS();
 
+  /**
+   * Enable NSNull conversion when handling module arguments on iOS
+   */
+  RN_EXPORT static bool enableModuleArgumentNSNullConversionIOS();
+
   /**
    * Parse CSS strings using the Fabric CSS parser instead of ViewConfig processing
    */

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<<ec175b9b320e8bf9b0811ba404cd6e5d>>
+ * @generated SignedSource<<955524ea199666cfdd38ab4b73efcd2a>>
  */
 
 /**
@@ -461,6 +461,24 @@ bool ReactNativeFeatureFlagsAccessor::enableMainQueueModulesOnIOS() {
   return flagValue.value();
 }
 
+bool ReactNativeFeatureFlagsAccessor::enableModuleArgumentNSNullConversionIOS() {
+  auto flagValue = enableModuleArgumentNSNullConversionIOS_.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(24, "enableModuleArgumentNSNullConversionIOS");
+
+    flagValue = currentProvider_->enableModuleArgumentNSNullConversionIOS();
+    enableModuleArgumentNSNullConversionIOS_ = flagValue;
+  }
+
+  return flagValue.value();
+}
+
 bool ReactNativeFeatureFlagsAccessor::enableNativeCSSParsing() {
   auto flagValue = enableNativeCSSParsing_.load();
 
@@ -470,7 +488,7 @@ bool ReactNativeFeatureFlagsAccessor::enableNativeCSSParsing() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(24, "enableNativeCSSParsing");
+    markFlagAsAccessed(25, "enableNativeCSSParsing");
 
     flagValue = currentProvider_->enableNativeCSSParsing();
     enableNativeCSSParsing_ = flagValue;
@@ -488,7 +506,7 @@ bool ReactNativeFeatureFlagsAccessor::enableNetworkEventReporting() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(25, "enableNetworkEventReporting");
+    markFlagAsAccessed(26, "enableNetworkEventReporting");
 
     flagValue = currentProvider_->enableNetworkEventReporting();
     enableNetworkEventReporting_ = flagValue;
@@ -506,7 +524,7 @@ bool ReactNativeFeatureFlagsAccessor::enableNewBackgroundAndBorderDrawables() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(26, "enableNewBackgroundAndBorderDrawables");
+    markFlagAsAccessed(27, "enableNewBackgroundAndBorderDrawables");
 
     flagValue = currentProvider_->enableNewBackgroundAndBorderDrawables();
     enableNewBackgroundAndBorderDrawables_ = flagValue;
@@ -524,7 +542,7 @@ bool ReactNativeFeatureFlagsAccessor::enablePreparedTextLayout() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(27, "enablePreparedTextLayout");
+    markFlagAsAccessed(28, "enablePreparedTextLayout");
 
     flagValue = currentProvider_->enablePreparedTextLayout();
     enablePreparedTextLayout_ = flagValue;
@@ -542,7 +560,7 @@ bool ReactNativeFeatureFlagsAccessor::enablePropsUpdateReconciliationAndroid() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(28, "enablePropsUpdateReconciliationAndroid");
+    markFlagAsAccessed(29, "enablePropsUpdateReconciliationAndroid");
 
     flagValue = currentProvider_->enablePropsUpdateReconciliationAndroid();
     enablePropsUpdateReconciliationAndroid_ = flagValue;
@@ -560,7 +578,7 @@ bool ReactNativeFeatureFlagsAccessor::enableResourceTimingAPI() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(29, "enableResourceTimingAPI");
+    markFlagAsAccessed(30, "enableResourceTimingAPI");
 
     flagValue = currentProvider_->enableResourceTimingAPI();
     enableResourceTimingAPI_ = flagValue;
@@ -578,7 +596,7 @@ bool ReactNativeFeatureFlagsAccessor::enableSynchronousStateUpdates() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(30, "enableSynchronousStateUpdates");
+    markFlagAsAccessed(31, "enableSynchronousStateUpdates");
 
     flagValue = currentProvider_->enableSynchronousStateUpdates();
     enableSynchronousStateUpdates_ = flagValue;
@@ -596,7 +614,7 @@ bool ReactNativeFeatureFlagsAccessor::enableViewCulling() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(31, "enableViewCulling");
+    markFlagAsAccessed(32, "enableViewCulling");
 
     flagValue = currentProvider_->enableViewCulling();
     enableViewCulling_ = flagValue;
@@ -614,7 +632,7 @@ bool ReactNativeFeatureFlagsAccessor::enableViewRecycling() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(32, "enableViewRecycling");
+    markFlagAsAccessed(33, "enableViewRecycling");
 
     flagValue = currentProvider_->enableViewRecycling();
     enableViewRecycling_ = flagValue;
@@ -632,7 +650,7 @@ bool ReactNativeFeatureFlagsAccessor::enableViewRecyclingForText() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(33, "enableViewRecyclingForText");
+    markFlagAsAccessed(34, "enableViewRecyclingForText");
 
     flagValue = currentProvider_->enableViewRecyclingForText();
     enableViewRecyclingForText_ = flagValue;
@@ -650,7 +668,7 @@ bool ReactNativeFeatureFlagsAccessor::enableViewRecyclingForView() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(34, "enableViewRecyclingForView");
+    markFlagAsAccessed(35, "enableViewRecyclingForView");
 
     flagValue = currentProvider_->enableViewRecyclingForView();
     enableViewRecyclingForView_ = flagValue;
@@ -668,7 +686,7 @@ 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(35, "fixMappingOfEventPrioritiesBetweenFabricAndReact");
+    markFlagAsAccessed(36, "fixMappingOfEventPrioritiesBetweenFabricAndReact");
 
     flagValue = currentProvider_->fixMappingOfEventPrioritiesBetweenFabricAndReact();
     fixMappingOfEventPrioritiesBetweenFabricAndReact_ = flagValue;
@@ -686,7 +704,7 @@ 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(36, "fuseboxEnabledRelease");
+    markFlagAsAccessed(37, "fuseboxEnabledRelease");
 
     flagValue = currentProvider_->fuseboxEnabledRelease();
     fuseboxEnabledRelease_ = flagValue;
@@ -704,7 +722,7 @@ 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(37, "fuseboxNetworkInspectionEnabled");
+    markFlagAsAccessed(38, "fuseboxNetworkInspectionEnabled");
 
     flagValue = currentProvider_->fuseboxNetworkInspectionEnabled();
     fuseboxNetworkInspectionEnabled_ = flagValue;
@@ -722,7 +740,7 @@ bool ReactNativeFeatureFlagsAccessor::incorporateMaxLinesDuringAndroidLayout() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(38, "incorporateMaxLinesDuringAndroidLayout");
+    markFlagAsAccessed(39, "incorporateMaxLinesDuringAndroidLayout");
 
     flagValue = currentProvider_->incorporateMaxLinesDuringAndroidLayout();
     incorporateMaxLinesDuringAndroidLayout_ = flagValue;
@@ -740,7 +758,7 @@ 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(39, "traceTurboModulePromiseRejectionsOnAndroid");
+    markFlagAsAccessed(40, "traceTurboModulePromiseRejectionsOnAndroid");
 
     flagValue = currentProvider_->traceTurboModulePromiseRejectionsOnAndroid();
     traceTurboModulePromiseRejectionsOnAndroid_ = flagValue;
@@ -758,7 +776,7 @@ 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(40, "updateRuntimeShadowNodeReferencesOnCommit");
+    markFlagAsAccessed(41, "updateRuntimeShadowNodeReferencesOnCommit");
 
     flagValue = currentProvider_->updateRuntimeShadowNodeReferencesOnCommit();
     updateRuntimeShadowNodeReferencesOnCommit_ = flagValue;
@@ -776,7 +794,7 @@ 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(41, "useAlwaysAvailableJSErrorHandling");
+    markFlagAsAccessed(42, "useAlwaysAvailableJSErrorHandling");
 
     flagValue = currentProvider_->useAlwaysAvailableJSErrorHandling();
     useAlwaysAvailableJSErrorHandling_ = flagValue;
@@ -794,7 +812,7 @@ bool ReactNativeFeatureFlagsAccessor::useAndroidTextLayoutWidthDirectly() {
     // be accessing the provider multiple times but the end state of this
     // instance and the returned flag value would be the same.
 
-    markFlagAsAccessed(42, "useAndroidTextLayoutWidthDirectly");
+    markFlagAsAccessed(43, "useAndroidTextLayoutWidthDirectly");
 
     flagValue = currentProvider_->useAndroidTextLayoutWidthDirectly();
     useAndroidTextLayoutWidthDirectly_ = flagValue;
@@ -812,7 +830,7 @@ 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(43, "useFabricInterop");
+    markFlagAsAccessed(44, "useFabricInterop");
 
     flagValue = currentProvider_->useFabricInterop();
     useFabricInterop_ = flagValue;
@@ -830,7 +848,7 @@ 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(44, "useNativeViewConfigsInBridgelessMode");
+    markFlagAsAccessed(45, "useNativeViewConfigsInBridgelessMode");
 
     flagValue = currentProvider_->useNativeViewConfigsInBridgelessMode();
     useNativeViewConfigsInBridgelessMode_ = flagValue;
@@ -848,7 +866,7 @@ 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(45, "useOptimizedEventBatchingOnAndroid");
+    markFlagAsAccessed(46, "useOptimizedEventBatchingOnAndroid");
 
     flagValue = currentProvider_->useOptimizedEventBatchingOnAndroid();
     useOptimizedEventBatchingOnAndroid_ = flagValue;
@@ -866,7 +884,7 @@ 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(46, "useRawPropsJsiValue");
+    markFlagAsAccessed(47, "useRawPropsJsiValue");
 
     flagValue = currentProvider_->useRawPropsJsiValue();
     useRawPropsJsiValue_ = flagValue;
@@ -884,7 +902,7 @@ 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(47, "useShadowNodeStateOnClone");
+    markFlagAsAccessed(48, "useShadowNodeStateOnClone");
 
     flagValue = currentProvider_->useShadowNodeStateOnClone();
     useShadowNodeStateOnClone_ = flagValue;
@@ -902,7 +920,7 @@ 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(48, "useTurboModuleInterop");
+    markFlagAsAccessed(49, "useTurboModuleInterop");
 
     flagValue = currentProvider_->useTurboModuleInterop();
     useTurboModuleInterop_ = flagValue;
@@ -920,7 +938,7 @@ 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(49, "useTurboModules");
+    markFlagAsAccessed(50, "useTurboModules");
 
     flagValue = currentProvider_->useTurboModules();
     useTurboModules_ = 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<<e1c1ba4c68d532a7296fa4f91a48de3a>>
+ * @generated SignedSource<<a95696cc00506fd1cc1e147e45a3098e>>
  */
 
 /**
@@ -56,6 +56,7 @@ class ReactNativeFeatureFlagsAccessor {
   bool enableLayoutAnimationsOnAndroid();
   bool enableLayoutAnimationsOnIOS();
   bool enableMainQueueModulesOnIOS();
+  bool enableModuleArgumentNSNullConversionIOS();
   bool enableNativeCSSParsing();
   bool enableNetworkEventReporting();
   bool enableNewBackgroundAndBorderDrawables();
@@ -93,7 +94,7 @@ class ReactNativeFeatureFlagsAccessor {
   std::unique_ptr<ReactNativeFeatureFlagsProvider> currentProvider_;
   bool wasOverridden_;
 
-  std::array<std::atomic<const char*>, 50> accessedFeatureFlags_;
+  std::array<std::atomic<const char*>, 51> accessedFeatureFlags_;
 
   std::atomic<std::optional<bool>> commonTestFlag_;
   std::atomic<std::optional<bool>> animatedShouldSignalBatch_;
@@ -119,6 +120,7 @@ class ReactNativeFeatureFlagsAccessor {
   std::atomic<std::optional<bool>> enableLayoutAnimationsOnAndroid_;
   std::atomic<std::optional<bool>> enableLayoutAnimationsOnIOS_;
   std::atomic<std::optional<bool>> enableMainQueueModulesOnIOS_;
+  std::atomic<std::optional<bool>> enableModuleArgumentNSNullConversionIOS_;
   std::atomic<std::optional<bool>> enableNativeCSSParsing_;
   std::atomic<std::optional<bool>> enableNetworkEventReporting_;
   std::atomic<std::optional<bool>> enableNewBackgroundAndBorderDrawables_;

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<<4c463bb7d1aa97478abe0e74955aa854>>
+ * @generated SignedSource<<c80be05a320b2cb0e78865492f503922>>
  */
 
 /**
@@ -123,6 +123,10 @@ class ReactNativeFeatureFlagsDefaults : public ReactNativeFeatureFlagsProvider {
     return false;
   }
 
+  bool enableModuleArgumentNSNullConversionIOS() override {
+    return true;
+  }
+
   bool enableNativeCSSParsing() 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<<f0c9d2d7027f9408bb7f784adcccbd51>>
+ * @generated SignedSource<<75a1b352cffa84394393992484dcb33c>>
  */
 
 /**
@@ -261,6 +261,15 @@ class ReactNativeFeatureFlagsDynamicProvider : public ReactNativeFeatureFlagsDef
     return ReactNativeFeatureFlagsDefaults::enableMainQueueModulesOnIOS();
   }
 
+  bool enableModuleArgumentNSNullConversionIOS() override {
+    auto value = values_["enableModuleArgumentNSNullConversionIOS"];
+    if (!value.isNull()) {
+      return value.getBool();
+    }
+
+    return ReactNativeFeatureFlagsDefaults::enableModuleArgumentNSNullConversionIOS();
+  }
+
   bool enableNativeCSSParsing() override {
     auto value = values_["enableNativeCSSParsing"];
     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<<53bd41086143a19f52e1e96025b24c76>>
+ * @generated SignedSource<<57a8881e00c4208f97c4eccac202a3bb>>
  */
 
 /**
@@ -49,6 +49,7 @@ class ReactNativeFeatureFlagsProvider {
   virtual bool enableLayoutAnimationsOnAndroid() = 0;
   virtual bool enableLayoutAnimationsOnIOS() = 0;
   virtual bool enableMainQueueModulesOnIOS() = 0;
+  virtual bool enableModuleArgumentNSNullConversionIOS() = 0;
   virtual bool enableNativeCSSParsing() = 0;
   virtual bool enableNetworkEventReporting() = 0;
   virtual bool enableNewBackgroundAndBorderDrawables() = 0;

packages/react-native/ReactCommon/react/nativemodule/core/iostests/RCTTurboModuleTests.mm

@@ -9,14 +9,21 @@
 
 #import <ReactCommon/RCTTurboModule.h>
 #import <hermes/hermes.h>
+#import <react/featureflags/ReactNativeFeatureFlags.h>
 
 #import <OCMock/OCMock.h>
 
 using namespace facebook::react;
 
-@protocol RCTTestTurboModule <RCTBridgeModule, RCTTurboModule>
+@interface RCTTestTurboModule : NSObject <RCTBridgeModule>
 
-- (void)testMethodWhichTakesObject:(id)object;
+@end
+
+@implementation RCTTestTurboModule
+
+RCT_EXPORT_MODULE()
+
+RCT_EXPORT_METHOD(testMethodWhichTakesObject : (id)object) {}
 
 @end
 
@@ -37,13 +44,13 @@ class StubNativeMethodCallInvoker : public NativeMethodCallInvoker {
 
 @implementation RCTTurboModuleTests {
   std::unique_ptr<ObjCTurboModule> module_;
-  id<RCTTestTurboModule> instance_;
+  RCTTestTurboModule *instance_;
 }
 
 - (void)setUp
 {
   [super setUp];
-  instance_ = OCMProtocolMock(@protocol(RCTTestTurboModule));
+  instance_ = OCMClassMock([RCTTestTurboModule class]);
 
   ObjCTurboModule::InitParams params = {
       .moduleName = "TestModule",
@@ -82,11 +89,14 @@ class StubNativeMethodCallInvoker : public NativeMethodCallInvoker {
   OCMVerify(OCMTimes(1), [instance_ testMethodWhichTakesObject:@{@"foo" : @"bar"}]);
 
   // Object with key without value
-  args[0].asObject(*rt).setProperty(*rt, "foo", "facebook::jsi::Value::undefined()");
+  args[0].asObject(*rt).setProperty(*rt, "foo", facebook::jsi::Value::null());
   module_->invokeObjCMethod(
       *rt, VoidKind, "testMethodWhichTakesObject", @selector(testMethodWhichTakesObject:), args, 1);
-  // FIXME this should be called with @{@"foo": kCFNull}
-  OCMVerify(OCMTimes(1), [instance_ testMethodWhichTakesObject:@{}]);
+  if (ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS()) {
+    OCMVerify(OCMTimes(1), [instance_ testMethodWhichTakesObject:@{@"foo" : (id)kCFNull}]);
+  } else {
+    OCMVerify(OCMTimes(2), [instance_ testMethodWhichTakesObject:@{}]);
+  }
 
   // Null
   args[0] = facebook::jsi::Value::null();

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

@@ -18,6 +18,7 @@
 #import <ReactCommon/TurboModulePerfLogger.h>
 #import <cxxreact/TraceSection.h>
 #import <react/bridging/Bridging.h>
+#import <react/featureflags/ReactNativeFeatureFlags.h>
 
 #include <glog/logging.h>
 
@@ -622,7 +623,9 @@ void ObjCTurboModule::setInvocationArg(
   /**
    * Convert arg to ObjC objects.
    */
-  id objCArg = convertJSIValueToObjCObject(runtime, arg, jsInvoker_);
+  BOOL enableModuleArgumentNSNullConversionIOS = ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS();
+  id objCArg = TurboModuleConvertUtils::convertJSIValueToObjCObject(
+      runtime, arg, jsInvoker_, enableModuleArgumentNSNullConversionIOS);
   if (objCArg) {
     NSString *methodNameNSString = @(methodName);
 
@@ -640,6 +643,10 @@ void ObjCTurboModule::setInvocationArg(
           id (*convert)(id, SEL, id) = (__typeof__(convert))objc_msgSend;
           id convertedObjCArg = convert([RCTConvert class], rctConvertSelector, objCArg);
 
+          if (enableModuleArgumentNSNullConversionIOS && convertedObjCArg == [NSNull null]) {
+            return;
+          }
+
           [inv setArgument:(void *)&convertedObjCArg atIndex:i + 2];
           if (convertedObjCArg) {
             [retainedObjectsForInvocation addObject:convertedObjCArg];

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<<74f011324e9d4647fa757f29b602c6c3>>
+ * @generated SignedSource<<167e35bd99451cbe24a2bb54db5c66b9>>
  */
 
 /**
@@ -164,6 +164,11 @@ bool NativeReactNativeFeatureFlags::enableMainQueueModulesOnIOS(
   return ReactNativeFeatureFlags::enableMainQueueModulesOnIOS();
 }
 
+bool NativeReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS(
+    jsi::Runtime& /*runtime*/) {
+  return ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS();
+}
+
 bool NativeReactNativeFeatureFlags::enableNativeCSSParsing(
     jsi::Runtime& /*runtime*/) {
   return ReactNativeFeatureFlags::enableNativeCSSParsing();

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<<2b33a7fe9086343c427f06cc62c67a62>>
+ * @generated SignedSource<<196bc6e1f0196c39029c3d2a45d3254b>>
  */
 
 /**
@@ -85,6 +85,8 @@ class NativeReactNativeFeatureFlags
 
   bool enableMainQueueModulesOnIOS(jsi::Runtime& runtime);
 
+  bool enableModuleArgumentNSNullConversionIOS(jsi::Runtime& runtime);
+
   bool enableNativeCSSParsing(jsi::Runtime& runtime);
 
   bool enableNetworkEventReporting(jsi::Runtime& runtime);

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

@@ -299,6 +299,16 @@ const definitions: FeatureFlagDefinitions = {
       },
       ossReleaseStage: 'none',
     },
+    enableModuleArgumentNSNullConversionIOS: {
+      defaultValue: true,
+      metadata: {
+        description:
+          'Enable NSNull conversion when handling module arguments on iOS',
+        expectedReleaseValue: true,
+        purpose: 'release',
+      },
+      ossReleaseStage: 'none',
+    },
     enableNativeCSSParsing: {
       defaultValue: false,
       metadata: {

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<<e640d7299f0b0624f9dce91e7a39604c>>
+ * @generated SignedSource<<cbcc6da9a0d0652dddd99977690a258a>>
  * @flow strict
  * @noformat
  */
@@ -74,6 +74,7 @@ export type ReactNativeFeatureFlags = $ReadOnly<{
   enableLayoutAnimationsOnAndroid: Getter<boolean>,
   enableLayoutAnimationsOnIOS: Getter<boolean>,
   enableMainQueueModulesOnIOS: Getter<boolean>,
+  enableModuleArgumentNSNullConversionIOS: Getter<boolean>,
   enableNativeCSSParsing: Getter<boolean>,
   enableNetworkEventReporting: Getter<boolean>,
   enableNewBackgroundAndBorderDrawables: Getter<boolean>,
@@ -277,6 +278,10 @@ export const enableLayoutAnimationsOnIOS: Getter<boolean> = createNativeFlagGett
  * Makes modules requiring main queue setup initialize on the main thread, during React Native init.
  */
 export const enableMainQueueModulesOnIOS: Getter<boolean> = createNativeFlagGetter('enableMainQueueModulesOnIOS', false);
+/**
+ * Enable NSNull conversion when handling module arguments on iOS
+ */
+export const enableModuleArgumentNSNullConversionIOS: Getter<boolean> = createNativeFlagGetter('enableModuleArgumentNSNullConversionIOS', true);
 /**
  * Parse CSS strings using the Fabric CSS parser instead of ViewConfig processing
  */

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<<620ba7ace3df80067aa6ba1ed44aec60>>
+ * @generated SignedSource<<b12383e2b1e15b8a062efd33eb52070f>>
  * @flow strict
  * @noformat
  */
@@ -49,6 +49,7 @@ export interface Spec extends TurboModule {
   +enableLayoutAnimationsOnAndroid?: () => boolean;
   +enableLayoutAnimationsOnIOS?: () => boolean;
   +enableMainQueueModulesOnIOS?: () => boolean;
+  +enableModuleArgumentNSNullConversionIOS?: () => boolean;
   +enableNativeCSSParsing?: () => boolean;
   +enableNetworkEventReporting?: () => boolean;
   +enableNewBackgroundAndBorderDrawables?: () => boolean;