Move Flipper integration to a separate Gradle module inside ReactAndroid (#37688)

Summary:
Pull Request resolved: #37688

This moves the `ReactNativeFlipper` classes used to configure Flipper on Android from the template to
a separate Gradle artifact that will be published under the coordinates:
```
com.facebook.react:flipper-integration:0.73.x
```

This reduces the footprint of Flipper on the app template and makes easier for user on 0.73 to migrate
to Kotlin (as they will now have to migrate only 2 files rather than 4).

Changelog:
[Android] [Changed] - Move Flipper integration to a separate Gradle module inside `ReactAndroid`

Reviewed By: huntie

Differential Revision: D46441588

fbshipit-source-id: e197f29b7386b52091b8d38ed09bbd8f74a997df

Author: cortinico

.gitignore

@@ -39,6 +39,7 @@ project.xcworkspace
 /packages/react-native/ReactAndroid/gradlew.bat
 /packages/react-native/ReactAndroid/external-artifacts/build/
 /packages/react-native/ReactAndroid/external-artifacts/artifacts/
+/packages/react-native/ReactAndroid/flipper-integration/build/
 /packages/react-native/ReactAndroid/hermes-engine/build/
 /packages/react-native/ReactAndroid/hermes-engine/.cxx/
 /packages/react-native/template/android/app/build/

build.gradle.kts

@@ -99,6 +99,8 @@ tasks.register("publishAllToMavenTempLocal") {
   description = "Publish all the artifacts to be available inside a Maven Local repository on /tmp."
   dependsOn(":packages:react-native:ReactAndroid:publishAllPublicationsToMavenTempLocalRepository")
   // We don't publish the external-artifacts to Maven Local as CircleCI is using it via workspace.
+  dependsOn(
+      ":packages:react-native:ReactAndroid:flipper-integration:publishAllPublicationsToMavenTempLocalRepository")
   dependsOn(
       ":packages:react-native:ReactAndroid:hermes-engine:publishAllPublicationsToMavenTempLocalRepository")
 }
@@ -107,5 +109,6 @@ tasks.register("publishAllToSonatype") {
   description = "Publish all the artifacts to Sonatype (Maven Central or Snapshot repository)"
   dependsOn(":packages:react-native:ReactAndroid:publishToSonatype")
   dependsOn(":packages:react-native:ReactAndroid:external-artifacts:publishToSonatype")
+  dependsOn(":packages:react-native:ReactAndroid:flipper-integration:publishToSonatype")
   dependsOn(":packages:react-native:ReactAndroid:hermes-engine:publishToSonatype")
 }

packages/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/utils/DependencyUtils.kt

@@ -45,7 +45,8 @@ internal object DependencyUtils {
   /**
    * This method takes care of configuring the resolution strategy for both the app and all the 3rd
    * party libraries which are auto-linked. Specifically it takes care of:
-   * - Forcing the react-android/hermes-android version to the one specified in the package.json
+   * - Forcing the react-android/hermes-android/flipper-integration version to the one specified in
+   *   the package.json
    * - Substituting `react-native` with `react-android` and `hermes-engine` with `hermes-android`.
    */
   fun configureDependencies(
@@ -68,6 +69,7 @@ internal object DependencyUtils {
         configuration.resolutionStrategy.force(
             "${groupString}:react-android:${versionString}",
             "${groupString}:hermes-android:${versionString}",
+            "${groupString}:flipper-integration:${versionString}",
         )
       }
     }

packages/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/utils/NdkConfiguratorUtils.kt

@@ -78,7 +78,7 @@ internal object NdkConfiguratorUtils {
   ) {
     if (!project.isNewArchEnabled) {
       // For Old Arch, we set a pickFirst only on libraries that we know are
-      // clashing with our direct dependencies (FBJNI, Flipper and Hermes).
+      // clashing with our direct dependencies (mainly FBJNI and Hermes).
       variant.packaging.jniLibs.pickFirsts.addAll(
           listOf(
               "**/libfbjni.so",

packages/react-native/ReactAndroid/flipper-integration/.npmignore

@@ -0,0 +1,2 @@
+# Make sure we never publish the build folders to npm.
+build/

packages/react-native/ReactAndroid/flipper-integration/build.gradle

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+plugins {
+    id("com.android.library")
+    id("maven-publish")
+    id("signing")
+    id("org.jetbrains.kotlin.android")
+}
+
+group = "com.facebook.react"
+version = parent.publishing_version
+
+repositories {
+    // Normally RNGP will set repositories for all modules,
+    // but when consumed from source, we need to re-declare
+    // those repositories as there is no app module there.
+    mavenCentral()
+    google()
+}
+
+android {
+    compileSdk 33
+    buildToolsVersion = "33.0.0"
+    namespace "com.facebook.react.flipper"
+
+    defaultConfig {
+        minSdk = 21
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
+
+    kotlin {
+        jvmToolchain(11)
+    }
+
+    dependencies {
+        implementation project(':packages:react-native:ReactAndroid')
+        debugImplementation("com.facebook.flipper:flipper:${FLIPPER_VERSION}")
+        debugImplementation("com.facebook.flipper:flipper-network-plugin:${FLIPPER_VERSION}") {
+            exclude group:'com.squareup.okhttp3', module:'okhttp'
+        }
+        debugImplementation("com.facebook.flipper:flipper-fresco-plugin:${FLIPPER_VERSION}")
+    }
+
+    publishing {
+        multipleVariants {
+            withSourcesJar()
+            allVariants()
+        }
+    }
+}
+
+apply from: "../publish.gradle"

packages/react-native/ReactAndroid/flipper-integration/gradle.properties

@@ -0,0 +1,2 @@
+# Version of flipper SDK to use for this integration
+FLIPPER_VERSION=0.182.0

packages/react-native/template/android/app/src/debug/java/com/helloworld/ReactNativeFlipper.kt renamed to packages/react-native/ReactAndroid/flipper-integration/src/debug/java/com/facebook/react/flipper/ReactNativeFlipper.kt

@@ -1,4 +1,11 @@
-package com.helloworld
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.flipper
 
 import android.content.Context
 import com.facebook.flipper.android.AndroidFlipperClient
@@ -21,6 +28,7 @@ import com.facebook.react.modules.network.NetworkingModule
  * flavor of it. Here you can add your own plugins and customize the Flipper setup.
  */
 object ReactNativeFlipper {
+  @JvmStatic
   fun initializeFlipper(context: Context, reactInstanceManager: ReactInstanceManager) {
     if (FlipperUtils.shouldEnableFlipper(context)) {
       val client = AndroidFlipperClient.getInstance(context)

packages/react-native/template/android/app/src/release/java/com/helloworld/ReactNativeFlipper.kt renamed to packages/react-native/ReactAndroid/flipper-integration/src/release/java/com/facebook/react/flipper/ReactNativeFlipper.kt

@@ -1,4 +1,11 @@
-package com.helloworld
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.flipper
 
 import android.content.Context
 import com.facebook.react.ReactInstanceManager
@@ -9,6 +16,7 @@ import com.facebook.react.ReactInstanceManager
  */
 object ReactNativeFlipper {
   @Suppress("UNUSED_PARAMETER")
+  @JvmStatic
   fun initializeFlipper(context: Context, reactInstanceManager: ReactInstanceManager) {
     // Do nothing as we don't want to initialize Flipper on Release.
   }

packages/react-native/settings.gradle.kts

@@ -29,3 +29,8 @@ include(":packages:react-native:ReactAndroid:hermes-engine")
 
 project(":packages:react-native:ReactAndroid:hermes-engine").projectDir =
     file("ReactAndroid/hermes-engine/")
+
+include(":packages:react-native:ReactAndroid:flipper-integration")
+
+project(":packages:react-native:ReactAndroid:flipper-integration").projectDir =
+    file("ReactAndroid/flipper-integration/")