expo-modules-gradle8-migration.md

Gradle 8 Migration for Custom Expo Modules

Starting from Expo SDK 49 (React Native 0.72), the React Native Android project uses Gradle 8 as the default version. If your project includes custom Expo Modules, you might encounter build errors or warnings related to this change. This migration guide provides step-by-step instructions to resolve any issues and ensure Gradle 8 compatibility.

Error: Unknown property classifier

If you encounter an error similar to the following:

* What went wrong:
A problem occurred evaluating project ':tester'.
> Could not set unknown property 'classifier' for task ':tester:androidSourcesJar' of type org.gradle.api.tasks.bundling.Jar.

You can apply the following patch to your module's build.gradle file to resolve the issue:

--- a/modules/tester/android/build.gradle
+++ b/modules/tester/android/build.gradle
@@ -35,19 +35,11 @@ buildscript {
   }
 }

-// Creating sources with comments
-task androidSourcesJar(type: Jar) {
-  classifier = 'sources'
-  from android.sourceSets.main.java.srcDirs
-}
-
 afterEvaluate {
   publishing {
     publications {
       release(MavenPublication) {
         from components.release
-        // Add additional sourcesJar to artifacts
-        artifact(androidSourcesJar)
       }
     }
   }
 }
 
 android {
   lintOptions {
     abortOnError false
   }
+  publishing {
+    singleVariant("release") {
+      withSourcesJar()
+    }
+  }
 }

 repositories {

Error: task (current target is 17) and 'compileReleaseKotlin' task (current target is 11) jvm target compatibility should be set to the same Java version.

When upgrading Expo SDK 50 from your existing Android project, you may get a similar error:

> 'compileReleaseJavaWithJavac' task (current target is 17) and 'compileReleaseKotlin' task (current target is 11) jvm target compatibility should be set to the same Java version.
  Consider using JVM toolchain: https://kotl.in/gradle/jvm/toolchain

Since Expo SDK 50 or React Native 0.73, the JVM target version will be setup by @react-native/gradle-plugin and JVM toolchain. You can remove the previous JVM target version in your library's build.gradle:

--- a/android/build.gradle
+++ b/android/build.gradle
@@ -53,13 +53,16 @@ afterEvaluate {
 android {
   compileSdkVersion safeExtGet("compileSdkVersion", 34)
 
-  compileOptions {
-    sourceCompatibility JavaVersion.VERSION_11
-    targetCompatibility JavaVersion.VERSION_11
-  }
+  def agpVersion = com.android.Version.ANDROID_GRADLE_PLUGIN_VERSION
+  if (agpVersion.tokenize('.')[0].toInteger() < 8) {
+    compileOptions {
+      sourceCompatibility JavaVersion.VERSION_11
+      targetCompatibility JavaVersion.VERSION_11
+    }
 
-  kotlinOptions {
-    jvmTarget = JavaVersion.VERSION_11.majorVersion
+    kotlinOptions {
+      jvmTarget = JavaVersion.VERSION_11.majorVersion
+    }
   }

Warning: Setting the namespace via a source AndroidManifest.xml's package attribute is deprecated.

If you see a warning similar to the following:

package="com.tester" found in source AndroidManifest.xml: /path/to/modules/tester/android/src/main/AndroidManifest.xml.
Setting the namespace via a source AndroidManifest.xml's package attribute is deprecated.
Please instead set the namespace (or testNamespace) in the module's build.gradle file, as described here: https://developer.android.com/studio/build/configure-app-module#set-namespace
This migration can be done automatically using the AGP Upgrade Assistant, please refer to https://developer.android.com/studio/build/agp-upgrade-assistant for more information.

Please note that this warning will become an error starting from React Native 0.73. To address the issue in advance, you can follow these steps:

1. Open your module's build.gradle file.

2. Locate the android block and add the following line:

   --- a/modules/tester/android/build.gradle
   +++ b/modules/tester/android/build.gradle
   @@ -59,6 +51,7 @@ afterEvaluate {
   }
   
   android {
   +  namespace = "com.tester"
      compileSdkVersion safeExtGet("compileSdkVersion", 33)
   
      compileOptions {

3. Open your module's AndroidManifest.xml file.

4. Replace the package attribute with namespace, as shown in the following patch:

   --- a/modules/tester/android/src/main/AndroidManifest.xml
   +++ b/modules/tester/android/src/main/AndroidManifest.xml
   @@ -1,2 +1,2 @@
   -<manifest package="com.tester">
   +<manifest>
    </manifest>

By following these steps, you will address the deprecation warning and ensure compatibility with Gradle 8.