Use Gradle KTS in new Android app projects by default (#154061)

This PR resolves #151166

dev/devicelab/bin/tasks/engine_dependency_proxy_test.dart

@@ -29,14 +29,17 @@ Future<void> main() async {
     await runProjectTest((FlutterProject flutterProject) async {
       await inDirectory(path.join(flutterProject.rootPath, 'android'), () async {
         section('Insert gradle testing script');
-        final File build = File(path.join(
+        final File buildFile = getAndroidBuildFile(path.join(flutterProject.rootPath, 'android'));
-          flutterProject.rootPath, 'android', 'app', 'build.gradle',
+        buildFile.writeAsStringSync(
-        ));
-        build.writeAsStringSync(
           '''
-task printEngineMavenUrl() {
+tasks.register("printEngineMavenUrl") {
     doLast {
-        println project.repositories.find { it.name == 'maven' }.url
+        project.repositories.forEach { repo ->
+            if (repo.name == "maven") {
+                repo as MavenArtifactRepository
+                logger.quiet(repo.url.toString())
+            }
+        }
     }
 }
           ''',

dev/devicelab/lib/framework/apk_utils.dart

@@ -256,18 +256,17 @@ class FlutterProject {
   String get rootPath => path.join(parent.path, name);
   String get androidPath => path.join(rootPath, 'android');
   String get iosPath => path.join(rootPath, 'ios');
+  File get appBuildFile => getAndroidBuildFile(androidPath);
 
   Future<void> addCustomBuildType(String name, {required String initWith}) async {
-    final File buildScript = File(
+    final File buildScript = appBuildFile;
-      path.join(androidPath, 'app', 'build.gradle'),
-    );
 
     buildScript.openWrite(mode: FileMode.append).write('''
 
 android {
     buildTypes {
-        $name {
+        create("$name") {
-            initWith $initWith
+            initWith(getByName("$initWith"))
         }
     }
 }
@@ -288,14 +287,12 @@ android {
   }
 
   Future<void> setMinSdkVersion(int sdkVersion) async {
-    final File buildScript = File(
+    final File buildScript = appBuildFile;
-      path.join(androidPath, 'app', 'build.gradle'),
-    );
 
     buildScript.openWrite(mode: FileMode.append).write('''
 android {
     defaultConfig {
-        minSdkVersion $sdkVersion
+        minSdk = $sdkVersion
     }
 }
     ''');
@@ -308,22 +305,20 @@ android {
   }
 
   Future<void> addProductFlavors(Iterable<String> flavors) async {
-    final File buildScript = File(
+    final File buildScript = appBuildFile;
-      path.join(androidPath, 'app', 'build.gradle'),
-    );
 
     final String flavorConfig = flavors.map((String name) {
       return '''
-$name {
+create("$name") {
-    applicationIdSuffix ".$name"
+    applicationIdSuffix = ".$name"
-    versionNameSuffix "-$name"
+    versionNameSuffix = "-$name"
 }
       ''';
     }).join('\n');
 
     buildScript.openWrite(mode: FileMode.append).write('''
 android {
-    flavorDimensions "mode"
+    flavorDimensions.add("mode")
     productFlavors {
         $flavorConfig
     }
@@ -332,9 +327,7 @@ android {
   }
 
   Future<void> introduceError() async {
-    final File buildScript = File(
+    final File buildScript = appBuildFile;
-      path.join(androidPath, 'app', 'build.gradle'),
-    );
     await buildScript.writeAsString((await buildScript.readAsString()).replaceAll('buildTypes', 'builTypes'));
   }
 
@@ -477,3 +470,14 @@ String? validateSnapshotDependency(FlutterProject project, String expectedTarget
   return contentSnapshot.contains('$expectedTarget ')
     ? null : 'Dependency file should have $expectedTarget as target. Instead found $contentSnapshot';
 }
+
+File getAndroidBuildFile(String androidPath) {
+  final File groovyFile = File(path.join(androidPath, 'app', 'build.gradle'));
+  final File kotlinFile = File(path.join(androidPath, 'app', 'build.gradle.kts'));
+
+  if (groovyFile.existsSync()) {
+    return groovyFile;
+  }
+
+  return kotlinFile;
+}

packages/flutter_tools/lib/src/project.dart

@@ -467,7 +467,19 @@ class AndroidProject extends FlutterProjectPlatform {
   static final RegExp _androidNamespacePattern = RegExp('android {[\\S\\s]+namespace\\s*=?\\s*[\'"](.+)[\'"]');
   static final RegExp _applicationIdPattern = RegExp('^\\s*applicationId\\s*=?\\s*[\'"](.*)[\'"]\\s*\$');
   static final RegExp _imperativeKotlinPluginPattern = RegExp('^\\s*apply plugin\\:\\s+[\'"]kotlin-android[\'"]\\s*\$');
-  static final RegExp _declarativeKotlinPluginPattern = RegExp('^\\s*id\\s+[\'"]kotlin-android[\'"]\\s*\$');
+
+  /// Examples of strings that this regex matches:
+  /// - `id "kotlin-android"`
+  /// - `id("kotlin-android")`
+  /// - `id ( "kotlin-android" ) `
+  /// - `id "org.jetbrains.kotlin.android"`
+  /// - `id("org.jetbrains.kotlin.android")`
+  /// - `id ( "org.jetbrains.kotlin.android" )`
+  static final List<RegExp> _declarativeKotlinPluginPatterns = <RegExp>[
+      RegExp('^\\s*id\\s*\\(?\\s*[\'"]kotlin-android[\'"]\\s*\\)?\\s*\$'),
+      RegExp('^\\s*id\\s*\\(?\\s*[\'"]org.jetbrains.kotlin.android[\'"]\\s*\\)?\\s*\$'),
+  ];
+
 
   /// Pattern used to find the assignment of the "group" property in Gradle.
   /// Expected example: `group "dev.flutter.plugin"`
@@ -563,7 +575,9 @@ class AndroidProject extends FlutterProjectPlatform {
   /// True, if the app project is using Kotlin.
   bool get isKotlin {
     final bool imperativeMatch = firstMatchInFile(appGradleFile, _imperativeKotlinPluginPattern) != null;
-    final bool declarativeMatch = firstMatchInFile(appGradleFile, _declarativeKotlinPluginPattern) != null;
+    final bool declarativeMatch = _declarativeKotlinPluginPatterns.any((RegExp pattern) {
+      return (firstMatchInFile(appGradleFile, pattern) != null);
+    });
     return imperativeMatch || declarativeMatch;
   }
 

packages/flutter_tools/templates/app_shared/android-java.tmpl/app/build.gradle.kts.tmpl

@@ -1,8 +1,8 @@
 plugins {
-    id "com.android.application"
+    id("com.android.application")
-    id "kotlin-android"
+    id("kotlin-android")
     // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
-    id "dev.flutter.flutter-gradle-plugin"
+    id("dev.flutter.flutter-gradle-plugin")
 }
 
 android {
@@ -16,7 +16,7 @@ android {
     }
 
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_1_8
+        jvmTarget = JavaVersion.VERSION_1_8.toString()
     }
 
     defaultConfig {
@@ -34,7 +34,7 @@ android {
         release {
             // TODO: Add your own signing config for the release build.
             // Signing with the debug keys for now, so `flutter run --release` works.
-            signingConfig = signingConfigs.debug
+            signingConfig = signingConfigs.getByName("debug")
         }
     }
 }

packages/flutter_tools/templates/app_shared/android-java.tmpl/build.gradle.kts.tmpl

@@ -0,0 +1,18 @@
+allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.buildDir = file("../build")
+subprojects {
+    project.buildDir = file("${rootProject.buildDir}/${project.name}")
+}
+subprojects {
+    project.evaluationDependsOn(":app")
+}
+
+tasks.register<Delete>("clean") {
+    delete(rootProject.buildDir)
+}

packages/flutter_tools/templates/app_shared/android-java.tmpl/build.gradle.tmpl

@@ -1,18 +0,0 @@
-allprojects {
-    repositories {
-        google()
-        mavenCentral()
-    }
-}
-
-rootProject.buildDir = "../build"
-subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
-}
-subprojects {
-    project.evaluationDependsOn(":app")
-}
-
-tasks.register("clean", Delete) {
-    delete rootProject.buildDir
-}

packages/flutter_tools/templates/app_shared/android-kotlin.tmpl/app/build.gradle.kts.tmpl

@@ -1,8 +1,8 @@
 plugins {
-    id "com.android.application"
+    id("com.android.application")
-    id "kotlin-android"
+    id("kotlin-android")
     // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
-    id "dev.flutter.flutter-gradle-plugin"
+    id("dev.flutter.flutter-gradle-plugin")
 }
 
 android {
@@ -16,7 +16,7 @@ android {
     }
 
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_1_8
+        jvmTarget = JavaVersion.VERSION_1_8.toString()
     }
 
     defaultConfig {
@@ -34,7 +34,7 @@ android {
         release {
             // TODO: Add your own signing config for the release build.
             // Signing with the debug keys for now, so `flutter run --release` works.
-            signingConfig = signingConfigs.debug
+            signingConfig = signingConfigs.getByName("debug")
         }
     }
 }

packages/flutter_tools/templates/app_shared/android-kotlin.tmpl/build.gradle.kts.tmpl

@@ -0,0 +1,18 @@
+allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.buildDir = file("../build")
+subprojects {
+    project.buildDir = file("${rootProject.buildDir}/${project.name}")
+}
+subprojects {
+    project.evaluationDependsOn(":app")
+}
+
+tasks.register<Delete>("clean") {
+    delete(rootProject.buildDir)
+}

packages/flutter_tools/templates/app_shared/android-kotlin.tmpl/build.gradle.tmpl

@@ -1,18 +0,0 @@
-allprojects {
-    repositories {
-        google()
-        mavenCentral()
-    }
-}
-
-rootProject.buildDir = "../build"
-subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
-}
-subprojects {
-    project.evaluationDependsOn(":app")
-}
-
-tasks.register("clean", Delete) {
-    delete rootProject.buildDir
-}

packages/flutter_tools/templates/app_shared/android.tmpl/settings.gradle.kts.tmpl

@@ -0,0 +1,25 @@
+pluginManagement {
+    val flutterSdkPath = run {
+        val properties = java.util.Properties()
+        file("local.properties").inputStream().use { properties.load(it) }
+        val flutterSdkPath = properties.getProperty("flutter.sdk")
+        require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
+        flutterSdkPath
+    }
+
+    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
+
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id("dev.flutter.flutter-plugin-loader") version "1.0.0"
+    id("com.android.application") version "{{agpVersion}}" apply false
+    id("org.jetbrains.kotlin.android") version "{{kotlinVersion}}" apply false
+}
+
+include(":app")

packages/flutter_tools/templates/app_shared/android.tmpl/settings.gradle.tmpl

@@ -1,25 +0,0 @@
-pluginManagement {
-    def flutterSdkPath = {
-        def properties = new Properties()
-        file("local.properties").withInputStream { properties.load(it) }
-        def flutterSdkPath = properties.getProperty("flutter.sdk")
-        assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
-        return flutterSdkPath
-    }()
-
-    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
-
-    repositories {
-        google()
-        mavenCentral()
-        gradlePluginPortal()
-    }
-}
-
-plugins {
-    id "dev.flutter.flutter-plugin-loader" version "1.0.0"
-    id "com.android.application" version "{{agpVersion}}" apply false
-    id "org.jetbrains.kotlin.android" version "{{kotlinVersion}}" apply false
-}
-
-include ":app"

packages/flutter_tools/templates/template_manifest.json

@@ -14,13 +14,13 @@
         "templates/app_shared/.idea/workspace.xml.tmpl",
         "templates/app_shared/.metadata.tmpl",
         "templates/app_shared/analysis_options.yaml.tmpl",
-        "templates/app_shared/android-java.tmpl/app/build.gradle.tmpl",
+        "templates/app_shared/android-java.tmpl/app/build.gradle.kts.tmpl",
         "templates/app_shared/android-java.tmpl/app/src/main/java/androidIdentifier/MainActivity.java.tmpl",
-        "templates/app_shared/android-java.tmpl/build.gradle.tmpl",
+        "templates/app_shared/android-java.tmpl/build.gradle.kts.tmpl",
         "templates/app_shared/android-java.tmpl/projectName_android.iml.tmpl",
-        "templates/app_shared/android-kotlin.tmpl/app/build.gradle.tmpl",
+        "templates/app_shared/android-kotlin.tmpl/app/build.gradle.kts.tmpl",
         "templates/app_shared/android-kotlin.tmpl/app/src/main/kotlin/androidIdentifier/MainActivity.kt.tmpl",
-        "templates/app_shared/android-kotlin.tmpl/build.gradle.tmpl",
+        "templates/app_shared/android-kotlin.tmpl/build.gradle.kts.tmpl",
         "templates/app_shared/android-kotlin.tmpl/projectName_android.iml.tmpl",
         "templates/app_shared/android.tmpl/.gitignore",
         "templates/app_shared/android.tmpl/app/src/debug/AndroidManifest.xml.tmpl",
@@ -36,7 +36,7 @@
         "templates/app_shared/android.tmpl/app/src/main/res/values/styles.xml",
         "templates/app_shared/android.tmpl/app/src/profile/AndroidManifest.xml.tmpl",
         "templates/app_shared/android.tmpl/gradle.properties.tmpl",
-        "templates/app_shared/android.tmpl/settings.gradle.tmpl",
+        "templates/app_shared/android.tmpl/settings.gradle.kts.tmpl",
         "templates/app_shared/android.tmpl/gradle/wrapper/gradle-wrapper.properties.tmpl",
         "templates/app_shared/android.tmpl/settings.gradle",
         "templates/app_shared/ios-objc.tmpl/Runner.xcodeproj/project.pbxproj.tmpl",

packages/flutter_tools/test/android_preview_integration.shard/flutter_build_preview_sdk_test.dart

@@ -44,7 +44,7 @@ void main() {
   test(
     'build succeeds targeting string compileSdkVersion',
     () async {
-      final File buildGradleFile = exampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle');
+      final File buildGradleFile = exampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle.kts');
       // write a build.gradle with compileSdkVersion as `android-UpsideDownCake` which is a string preview version
       buildGradleFile.writeAsStringSync(
         buildGradleFile.readAsStringSync().replaceFirst(compileSdkVersionMatch, 'compileSdkVersion = "android-UpsideDownCake"'),
@@ -72,7 +72,7 @@ void main() {
   test(
     'build succeeds targeting string compileSdkPreview',
     () async {
-      final File buildGradleFile = exampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle');
+      final File buildGradleFile = exampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle.kts');
       // write a build.gradle with compileSdkPreview as `UpsideDownCake` which is a string preview version
       buildGradleFile.writeAsStringSync(
         buildGradleFile.readAsStringSync().replaceFirst(compileSdkVersionMatch, 'compileSdkPreview = "UpsideDownCake"'),
@@ -100,7 +100,7 @@ void main() {
   test(
     'build succeeds when both example app and plugin target compileSdkPreview',
         () async {
-      final File appBuildGradleFile = exampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle');
+      final File appBuildGradleFile = exampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle.kts');
       // write a build.gradle with compileSdkPreview as `UpsideDownCake` which is a string preview version
       appBuildGradleFile.writeAsStringSync(
           appBuildGradleFile.readAsStringSync().replaceFirst(compileSdkVersionMatch, 'compileSdkPreview = "UpsideDownCake"'),

packages/flutter_tools/test/commands.shard/permeable/create_test.dart

@@ -3126,9 +3126,9 @@ void main() {
 
     await runner.run(<String>['create', '--no-pub', projectDir.path]);
 
-    expect(globals.fs.isFileSync('${projectDir.path}/android/app/build.gradle'), true);
+    expect(globals.fs.isFileSync('${projectDir.path}/android/app/build.gradle.kts'), true);
 
-    final String buildContent = await globals.fs.file('${projectDir.path}/android/app/build.gradle').readAsString();
+    final String buildContent = await globals.fs.file('${projectDir.path}/android/app/build.gradle.kts').readAsString();
 
     expect(buildContent.contains('compileSdk = flutter.compileSdkVersion'), true);
     expect(buildContent.contains('ndkVersion = flutter.ndkVersion'), true);

packages/flutter_tools/test/integration.shard/android_plugin_compilesdkversion_mismatch_test.dart

@@ -54,7 +54,7 @@ void main() {
 
     final Directory pluginExampleAppDir = pluginAppDir.childDirectory('example');
 
-    final File projectGradleFile = pluginExampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle');
+    final File projectGradleFile = pluginExampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle.kts');
     expect(projectGradleFile, exists);
 
     final String projectBuildGradle = projectGradleFile.readAsStringSync();

packages/flutter_tools/test/integration.shard/android_plugin_example_app_build_test.dart

@@ -51,7 +51,7 @@ void main() {
     final Directory exampleAppDir =
         tempDir.childDirectory(testName).childDirectory('example');
 
-    final File buildGradleFile = exampleAppDir.childDirectory('android').childFile('build.gradle');
+    final File buildGradleFile = exampleAppDir.childDirectory('android').childFile('build.gradle.kts');
     expect(buildGradleFile, exists);
 
     final String buildGradle = buildGradleFile.readAsStringSync();

packages/flutter_tools/test/integration.shard/android_plugin_ndkversion_mismatch_test.dart

@@ -53,7 +53,7 @@ void main() {
 
     final Directory pluginExampleAppDir = pluginAppDir.childDirectory('example');
 
-    final File projectGradleFile = pluginExampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle');
+    final File projectGradleFile = pluginExampleAppDir.childDirectory('android').childDirectory('app').childFile('build.gradle.kts');
     expect(projectGradleFile, exists);
 
     final String projectBuildGradle = projectGradleFile.readAsStringSync();

packages/flutter_tools/test/src/android_common.dart

@@ -160,7 +160,7 @@ Future<ProcessResult> buildFlutterApkWithSpecifiedDependencyVersions({
 
   if (versions.compileSdkVersion != null) {
     final File appGradleBuild = File(fileSystem.path.join(
-        app.path, 'android', 'app', 'build.gradle'));
+        app.path, 'android', 'app', 'build.gradle.kts'));
     final String appBuildContent = appGradleBuild.readAsStringSync()
         .replaceFirst(flutterCompileSdkString, versions.compileSdkVersion!);
     appGradleBuild.writeAsStringSync(appBuildContent);