Remove enableEagerMainQueueModulesOnIOS, make eager main-queue setup always-on

Summary:
The `enableEagerMainQueueModulesOnIOS` runtime gate has finished rollout and is no longer needed. Drop the flag from the feature-flag config, regenerate the per-language accessors, and inline the previously-gated body in `RCTInstance._start` so the eager main-queue module setup always runs. Also drops the now-dead override and trims the test that exercised the flag-off branch.

After this change, when `RCTInstance` starts up, it always consults `RCTInstanceDelegate.unstableModulesRequiringMainQueueSetup`, initializes the returned modules on the main queue, and blocks the JS thread on that completion before evaluating the bundle.

Changelog:
[iOS][Changed] - Native modules listed in `unstableModulesRequiringMainQueueSetup` are now always initialized eagerly on the main queue during React Native init; the previous `enableEagerMainQueueModulesOnIOS` opt-in flag has been removed.

Differential Revision: D105954235

Author: javache

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<<8b35aa70eea734a8bfcbb7bd651ba8e2>>
+ * @generated SignedSource<<23b48657a64e620a108351385cac9f79>>
  */
 
 /**
@@ -144,12 +144,6 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableDoubleMeasurementFixAndroid(): Boolean = accessor.enableDoubleMeasurementFixAndroid()
 
-  /**
-   * This infra allows native modules to initialize on the main thread, during React Native init.
-   */
-  @JvmStatic
-  public fun enableEagerMainQueueModulesOnIOS(): Boolean = accessor.enableEagerMainQueueModulesOnIOS()
-
   /**
    * Feature flag to configure eager attachment of the root view/initialisation of the JS code.
    */

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<<494ed85c58f80b4feb6fb9b83fe7a27e>>
+ * @generated SignedSource<<ac5eda3a3d3570fa615c8ed816b1fda5>>
  */
 
 /**
@@ -39,7 +39,6 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var enableDestroyShadowTreeRevisionAsyncCache: Boolean? = null
   private var enableDifferentiatorMutationVectorPreallocationCache: Boolean? = null
   private var enableDoubleMeasurementFixAndroidCache: Boolean? = null
-  private var enableEagerMainQueueModulesOnIOSCache: Boolean? = null
   private var enableEagerRootViewAttachmentCache: Boolean? = null
   private var enableExclusivePropsUpdateAndroidCache: Boolean? = null
   private var enableFabricCommitBranchingCache: Boolean? = null
@@ -282,15 +281,6 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
-  override fun enableEagerMainQueueModulesOnIOS(): Boolean {
-    var cached = enableEagerMainQueueModulesOnIOSCache
-    if (cached == null) {
-      cached = ReactNativeFeatureFlagsCxxInterop.enableEagerMainQueueModulesOnIOS()
-      enableEagerMainQueueModulesOnIOSCache = cached
-    }
-    return cached
-  }
-
   override fun enableEagerRootViewAttachment(): Boolean {
     var cached = enableEagerRootViewAttachmentCache
     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<<16ca9a4b47da90ea71300eb37287e28b>>
+ * @generated SignedSource<<32026408e198a903deb51eeb6157d3c5>>
  */
 
 /**
@@ -66,8 +66,6 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableDoubleMeasurementFixAndroid(): Boolean
 
-  @DoNotStrip @JvmStatic public external fun enableEagerMainQueueModulesOnIOS(): Boolean
-
   @DoNotStrip @JvmStatic public external fun enableEagerRootViewAttachment(): Boolean
 
   @DoNotStrip @JvmStatic public external fun enableExclusivePropsUpdateAndroid(): 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<<10e6516b3c9cf53ae2e48c8b8cd51033>>
+ * @generated SignedSource<<df4e0cc5b2eb2add539071a06eb07d14>>
  */
 
 /**
@@ -61,8 +61,6 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableDoubleMeasurementFixAndroid(): Boolean = false
 
-  override fun enableEagerMainQueueModulesOnIOS(): Boolean = false
-
   override fun enableEagerRootViewAttachment(): Boolean = false
 
   override fun enableExclusivePropsUpdateAndroid(): 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<<441fe8be28d4521e1fe9fe7b87b74cf2>>
+ * @generated SignedSource<<f812eec8119cbd3989dae4f6f43c8ba2>>
  */
 
 /**
@@ -43,7 +43,6 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var enableDestroyShadowTreeRevisionAsyncCache: Boolean? = null
   private var enableDifferentiatorMutationVectorPreallocationCache: Boolean? = null
   private var enableDoubleMeasurementFixAndroidCache: Boolean? = null
-  private var enableEagerMainQueueModulesOnIOSCache: Boolean? = null
   private var enableEagerRootViewAttachmentCache: Boolean? = null
   private var enableExclusivePropsUpdateAndroidCache: Boolean? = null
   private var enableFabricCommitBranchingCache: Boolean? = null
@@ -305,16 +304,6 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
-  override fun enableEagerMainQueueModulesOnIOS(): Boolean {
-    var cached = enableEagerMainQueueModulesOnIOSCache
-    if (cached == null) {
-      cached = currentProvider.enableEagerMainQueueModulesOnIOS()
-      accessedFeatureFlags.add("enableEagerMainQueueModulesOnIOS")
-      enableEagerMainQueueModulesOnIOSCache = cached
-    }
-    return cached
-  }
-
   override fun enableEagerRootViewAttachment(): Boolean {
     var cached = enableEagerRootViewAttachmentCache
     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<<972dbaef144818484bafff334cf97ef2>>
+ * @generated SignedSource<<f0e6af0192d195fb3fc4deaa1f269372>>
  */
 
 /**
@@ -61,8 +61,6 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableDoubleMeasurementFixAndroid(): Boolean
 
-  @DoNotStrip public fun enableEagerMainQueueModulesOnIOS(): Boolean
-
   @DoNotStrip public fun enableEagerRootViewAttachment(): Boolean
 
   @DoNotStrip public fun enableExclusivePropsUpdateAndroid(): 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<<bb79417efb0f63b2717ea8873b72da88>>
+ * @generated SignedSource<<37167dea60330101b87d35ee9cbd8531>>
  */
 
 /**
@@ -153,12 +153,6 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
-  bool enableEagerMainQueueModulesOnIOS() override {
-    static const auto method =
-        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableEagerMainQueueModulesOnIOS");
-    return method(javaProvider_);
-  }
-
   bool enableEagerRootViewAttachment() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableEagerRootViewAttachment");
@@ -678,11 +672,6 @@ bool JReactNativeFeatureFlagsCxxInterop::enableDoubleMeasurementFixAndroid(
   return ReactNativeFeatureFlags::enableDoubleMeasurementFixAndroid();
 }
 
-bool JReactNativeFeatureFlagsCxxInterop::enableEagerMainQueueModulesOnIOS(
-    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
-  return ReactNativeFeatureFlags::enableEagerMainQueueModulesOnIOS();
-}
-
 bool JReactNativeFeatureFlagsCxxInterop::enableEagerRootViewAttachment(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::enableEagerRootViewAttachment();
@@ -1121,9 +1110,6 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableDoubleMeasurementFixAndroid",
         JReactNativeFeatureFlagsCxxInterop::enableDoubleMeasurementFixAndroid),
-      makeNativeMethod(
-        "enableEagerMainQueueModulesOnIOS",
-        JReactNativeFeatureFlagsCxxInterop::enableEagerMainQueueModulesOnIOS),
       makeNativeMethod(
         "enableEagerRootViewAttachment",
         JReactNativeFeatureFlagsCxxInterop::enableEagerRootViewAttachment),

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<<3007628255a078dafc01eb16b3d55fbe>>
+ * @generated SignedSource<<cdd840b4cd4fdf22a4db023f464b981f>>
  */
 
 /**
@@ -87,9 +87,6 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableDoubleMeasurementFixAndroid(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
-  static bool enableEagerMainQueueModulesOnIOS(
-    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
-
   static bool enableEagerRootViewAttachment(
     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<<5c308b51617953c21d3ae60dc8c530bb>>
+ * @generated SignedSource<<30c0afbb7c40ba8953e5ffb692224a34>>
  */
 
 /**
@@ -102,10 +102,6 @@ bool ReactNativeFeatureFlags::enableDoubleMeasurementFixAndroid() {
   return getAccessor().enableDoubleMeasurementFixAndroid();
 }
 
-bool ReactNativeFeatureFlags::enableEagerMainQueueModulesOnIOS() {
-  return getAccessor().enableEagerMainQueueModulesOnIOS();
-}
-
 bool ReactNativeFeatureFlags::enableEagerRootViewAttachment() {
   return getAccessor().enableEagerRootViewAttachment();
 }

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<<ac9244d8e244e6ee81a39b6c6d3fbf5e>>
+ * @generated SignedSource<<b41796213163e3bae4f7e7ad75204d13>>
  */
 
 /**
@@ -134,11 +134,6 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableDoubleMeasurementFixAndroid();
 
-  /**
-   * This infra allows native modules to initialize on the main thread, during React Native init.
-   */
-  RN_EXPORT static bool enableEagerMainQueueModulesOnIOS();
-
   /**
    * Feature flag to configure eager attachment of the root view/initialisation of the JS code.
    */