Integrate Fabric into RN tester

Summary:
This diff integrates Fabric into RN Tester

changelog: [internal] internal

Reviewed By: JoshuaGross

Differential Revision: D23012446

fbshipit-source-id: 7a8410b0d73c26c347db17f6ec43663bb22524e3

RNTester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterActivity.java

@@ -7,12 +7,15 @@
 
 package com.facebook.react.uiapp;
 
+import static com.facebook.react.uiapp.RNTesterApplication.IS_FABRIC_ENABLED;
+
 import android.content.res.Configuration;
 import android.os.Bundle;
 import androidx.annotation.Nullable;
 import com.facebook.react.ReactActivity;
 import com.facebook.react.ReactActivityDelegate;
 import com.facebook.react.ReactInstanceManager;
+import com.facebook.react.ReactRootView;
 
 public class RNTesterActivity extends ReactActivity {
   public static class RNTesterActivityDelegate extends ReactActivityDelegate {
@@ -25,6 +28,13 @@ public class RNTesterActivity extends ReactActivity {
       this.mActivity = activity;
     }
 
+    @Override
+    protected ReactRootView createRootView() {
+      ReactRootView reactRootView = new ReactRootView(getContext());
+      reactRootView.setIsFabric(IS_FABRIC_ENABLED);
+      return reactRootView;
+    }
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
       // Get remote param before calling super which uses it

RNTester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterApplication.java

@@ -7,21 +7,39 @@
 
 package com.facebook.react.uiapp;
 
+import static com.facebook.react.uiapp.BuildConfig.FLAVOR;
+
 import android.app.Application;
 import android.content.Context;
+import androidx.annotation.Nullable;
 import com.facebook.react.BuildConfig;
 import com.facebook.react.ReactApplication;
 import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
+import com.facebook.react.bridge.JSIModulePackage;
+import com.facebook.react.bridge.JSIModuleProvider;
+import com.facebook.react.bridge.JSIModuleSpec;
+import com.facebook.react.bridge.JSIModuleType;
+import com.facebook.react.bridge.JavaScriptContextHolder;
+import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.UIManager;
+import com.facebook.react.fabric.ComponentFactory;
+import com.facebook.react.fabric.CoreComponentsRegistry;
+import com.facebook.react.fabric.FabricJSIModuleProvider;
+import com.facebook.react.fabric.ReactNativeConfig;
 import com.facebook.react.shell.MainReactPackage;
 import com.facebook.react.views.text.ReactFontManager;
 import com.facebook.soloader.SoLoader;
 import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 public class RNTesterApplication extends Application implements ReactApplication {
+
+  static final boolean IS_FABRIC_ENABLED = FLAVOR.contains("fabric");
+
   private final ReactNativeHost mReactNativeHost =
       new ReactNativeHost(this) {
         @Override
@@ -43,6 +61,63 @@ public class RNTesterApplication extends Application implements ReactApplication
         public List<ReactPackage> getPackages() {
           return Arrays.<ReactPackage>asList(new MainReactPackage());
         }
+
+        @Nullable
+        @Override
+        protected JSIModulePackage getJSIModulePackage() {
+          if (!IS_FABRIC_ENABLED) {
+            return null;
+          }
+
+          return new JSIModulePackage() {
+            @Override
+            public List<JSIModuleSpec> getJSIModules(
+                final ReactApplicationContext reactApplicationContext,
+                final JavaScriptContextHolder jsContext) {
+              List<JSIModuleSpec> specs = new ArrayList<>();
+              specs.add(
+                  new JSIModuleSpec() {
+                    @Override
+                    public JSIModuleType getJSIModuleType() {
+                      return JSIModuleType.UIManager;
+                    }
+
+                    @Override
+                    public JSIModuleProvider<UIManager> getJSIModuleProvider() {
+                      ComponentFactory ComponentFactory = new ComponentFactory();
+                      CoreComponentsRegistry.register(ComponentFactory);
+                      return new FabricJSIModuleProvider(
+                          reactApplicationContext,
+                          ComponentFactory,
+                          // TODO: T71362667 add ReactNativeConfig's support in RNTester
+                          new ReactNativeConfig() {
+                            @Override
+                            public boolean getBool(String s) {
+                              return true;
+                            }
+
+                            @Override
+                            public int getInt64(String s) {
+                              return 0;
+                            }
+
+                            @Override
+                            public String getString(String s) {
+                              return "";
+                            }
+
+                            @Override
+                            public double getDouble(String s) {
+                              return 0;
+                            }
+                          });
+                    }
+                  });
+
+              return specs;
+            }
+          };
+        }
       };
 
   @Override