Set concurrentRoot to true whenever Fabric is used in renderApplication (#42821)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/42821

As the title says, we want `concurrentRoot iif fabric`.
This makes sure we invoke renderApplication correctly.

Changelog:
[Internal] [Changed] - Set concurrentRoot to true whenever Fabric is used in renderApplication

Reviewed By: sammy-SC

Differential Revision: D53353017

fbshipit-source-id: 8de88adf528eb71f233233bd85c2c6ef9430fb16

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

@@ -42,7 +42,6 @@ NS_ASSUME_NONNULL_BEGIN
  *   - (UIViewController *)createRootViewController;
  *   - (void)setRootView:(UIView *)rootView toRootViewController:(UIViewController *)rootViewController;
  * New Architecture:
- *   - (BOOL)concurrentRootEnabled
  *   - (BOOL)turboModuleEnabled;
  *   - (BOOL)fabricEnabled;
  *   - (NSDictionary *)prepareInitialProps

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

@@ -39,8 +39,6 @@
 #import <react/renderer/runtimescheduler/RuntimeSchedulerCallInvoker.h>
 #import <react/runtime/JSRuntimeFactory.h>
 
-static NSString *const kRNConcurrentRoot = @"concurrentRoot";
-
 @interface RCTAppDelegate () <
     RCTTurboModuleManagerDelegate,
     RCTComponentViewFactoryComponentProvider,
@@ -53,9 +51,6 @@ static NSString *const kRNConcurrentRoot = @"concurrentRoot";
 static NSDictionary *updateInitialProps(NSDictionary *initialProps, BOOL isFabricEnabled)
 {
   NSMutableDictionary *mutableProps = [initialProps mutableCopy] ?: [NSMutableDictionary new];
-  // Hardcoding the Concurrent Root as it it not recommended to
-  // have the concurrentRoot turned off when Fabric is enabled.
-  mutableProps[kRNConcurrentRoot] = @(isFabricEnabled);
   return mutableProps;
 }
 

packages/react-native/Libraries/ReactNative/renderApplication.js

@@ -83,16 +83,13 @@ export default function renderApplication<Props: Object>(
     );
   }
 
-  if (fabric && !useConcurrentRoot) {
-    console.warn(
-      'Using Fabric without concurrent root is deprecated. Please enable concurrent root for this application.',
-    );
-  }
+  // We want to have concurrentRoot always enabled when you're on Fabric.
+  const useConcurrentRootOverride = fabric;
 
   performanceLogger.startTimespan('renderApplication_React_render');
   performanceLogger.setExtra(
     'usedReactConcurrentRoot',
-    useConcurrentRoot ? '1' : '0',
+    useConcurrentRootOverride ? '1' : '0',
   );
   performanceLogger.setExtra('usedReactFabric', fabric ? '1' : '0');
   performanceLogger.setExtra(
@@ -103,7 +100,7 @@ export default function renderApplication<Props: Object>(
     element: renderable,
     rootTag,
     useFabric: Boolean(fabric),
-    useConcurrentRoot: Boolean(useConcurrentRoot),
+    useConcurrentRoot: Boolean(useConcurrentRootOverride),
   });
   performanceLogger.stopTimespan('renderApplication_React_render');
 }

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

@@ -61,7 +61,6 @@ public class ReactActivityDelegate {
       if (composedLaunchOptions == null) {
         composedLaunchOptions = new Bundle();
       }
-      composedLaunchOptions.putBoolean("concurrentRoot", true);
     }
     return composedLaunchOptions;
   }

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

@@ -240,7 +240,6 @@ public class ReactDelegate {
       if (composedLaunchOptions == null) {
         composedLaunchOptions = new Bundle();
       }
-      composedLaunchOptions.putBoolean("concurrentRoot", true);
     }
     return composedLaunchOptions;
   }

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

@@ -340,9 +340,7 @@ public class ReactInstanceManager {
           ReactRootView rootView = new ReactRootView(currentActivity);
           boolean isFabric = ReactFeatureFlags.enableFabricRenderer;
           rootView.setIsFabric(isFabric);
-          Bundle launchOptions = new Bundle();
-          launchOptions.putBoolean("concurrentRoot", isFabric);
-          rootView.startReactApplication(ReactInstanceManager.this, appKey, launchOptions);
+          rootView.startReactApplication(ReactInstanceManager.this, appKey, new Bundle());
           return rootView;
         }
 

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

@@ -135,11 +135,8 @@ class BridgelessDevSupportManager extends DevSupportManagerBase {
       public View createRootView(String appKey) {
         Activity currentActivity = getCurrentActivity();
         if (currentActivity != null && !reactHost.isSurfaceWithModuleNameAttached(appKey)) {
-          Bundle launchOptions = new Bundle();
-          launchOptions.putBoolean("concurrentRoot", true);
-
           ReactSurfaceImpl reactSurface =
-              ReactSurfaceImpl.createWithView(currentActivity, appKey, launchOptions);
+              ReactSurfaceImpl.createWithView(currentActivity, appKey, new Bundle());
           reactSurface.attach(reactHost);
           reactSurface.start();
 

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/ReactActivityDelegateTest.kt

@@ -29,8 +29,8 @@ class ReactActivityDelegateTest {
         }
 
     assertNotNull(delegate.inspectLaunchOptions)
-    assertTrue(delegate.inspectLaunchOptions!!.containsKey("concurrentRoot"))
-    assertTrue(delegate.inspectLaunchOptions!!.getBoolean("concurrentRoot"))
+    // False because oncurrentRoot is hardcoded to true for Fabric inside renderApplication
+    assertFalse(delegate.inspectLaunchOptions!!.containsKey("concurrentRoot"))
   }
 
   @Test
@@ -60,8 +60,8 @@ class ReactActivityDelegateTest {
         }
 
     assertNotNull(delegate.inspectLaunchOptions)
-    assertTrue(delegate.inspectLaunchOptions!!.containsKey("concurrentRoot"))
-    assertTrue(delegate.inspectLaunchOptions!!.getBoolean("concurrentRoot"))
+    // False because oncurrentRoot is hardcoded to true for Fabric inside renderApplication
+    assertFalse(delegate.inspectLaunchOptions!!.containsKey("concurrentRoot"))
     assertTrue(delegate.inspectLaunchOptions!!.containsKey("test-property"))
     assertEquals("test-value", delegate.inspectLaunchOptions!!.getString("test-property"))
   }