Migration from Groovy to Kotlin DSL Gradle (Part 1)

For this article we will see the migration from the Groovy to the new Kotlin DSL Gradle file. I decided to write this article because when I try to migrate my projects Gradle files, I spent a lot of time to find all the correct codes from my personal projects, from different sources, from official Android developer sites, tutorials, forums etc. So, we will see the migration step by step. The article will be in two parts.

Note: In this article I will show some basics and common codes for Gradle files, that developers usually have in their Gradle files.

Migrations

First of all rename the Gradle file from build.gradle to build.gradle.kts. We can start the migration.

Groovy

plugins {
    id 'com.android.application'
    id 'kotlin-android'
}

Kotlin

plugins {
    id("com.android.application")
    id("kotlin-android")
}

Groovy

android {
    signingConfigs {
        release {
            storeFile file(".../app/keystoreFileName.keystore or keystoreFileName.jks")
            storePassword "storePassword"
            keyAlias "keyAlias"
            keyPassword "keyPassword"
        }
    }
    //...
}

Kotlin

android {
     signingConfigs {
        create("config") {
            keyAlias = "keyAlias"
            keyPassword = "keyPassword"
            storeFile = file(".../app/keystoreFileName.keystore or keystoreFileName.jks""")
            storePassword = "storePassword"
        }
    }
    //...
}

Groovy

android {
  //...
    buildToolsVersion '34.0.0'
    compileSdkVersion 34
    namespace 'com.myproject.myproject'
  //...
}

Kotlin

android {
  //...
    buildToolsVersion = "34.0.0"
    compileSdk = 34
    namespace = "com.myproject.myproject"
  //...
}

Groovy

defaultConfig {
        applicationId "com.myproject.myproject"
        minSdkVersion 27
        targetSdkVersion 34
        versionCode 1
        versionName "1.0.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        multiDexEnabled true

        buildFeatures {
            dataBinding true
            viewBinding true
            compose true
        }

        javaCompileOptions {
            annotationProcessorOptions {
                arguments += [
                        "room.incremental":"true"]
            }
        }

        vectorDrawables {
            useSupportLibrary true
        }

        buildTypes {
            release {
                shrinkResources true
                minifyEnabled true
                proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
            }
            debug {
                shrinkResources true
                minifyEnabled true
                proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
            }
        }

        ndk {
            abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
        }
        externalNativeBuild {
            cmake {
                cppFlags "-std=c++11 -fexceptions"
            }
        }
    }

Kotlin

defaultConfig {
        applicationId = "com.myproject.myproject"
        minSdk = 27
        targetSdk = 34
        versionCode = 1
        versionName = "1.0.0"
        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
        multiDexEnabled = true

        buildFeatures {
            dataBinding = true
            viewBinding = true
            compose = true
        }

        javaCompileOptions {
            annotationProcessorOptions {
                arguments += mapOf(
                    "room.incremental" to "true"
                )
            }
        }

        vectorDrawables {
            useSupportLibrary = true
        }

        buildTypes {
            release {
                isShrinkResources = true
                isMinifyEnabled = true
                proguardFiles(
                    getDefaultProguardFile("proguard-android-optimize.txt"),
                    "proguard-rules.pro"
                )
            }
            debug {
                isShrinkResources = true
                isMinifyEnabled = true
                proguardFiles(
                    getDefaultProguardFile("proguard-android-optimize.txt"),
                    "proguard-rules.pro"
                )
            }
        }

        ndk {
            abiFilters.add("armeabi-v7a")
            abiFilters.add("arm64-v8a")
            abiFilters.add("x86")
            abiFilters.add("x86_64")
        }
        externalNativeBuild {
            cmake {
                cppFlags("-std=c++11 -fexceptions")
            }
        }
    }

Groovy

externalNativeBuild {
        cmake {
            path "src/main/cpp/CMakeLists.txt"
            version "3.22.1"
        }
    }
ndkVersion '26.1.10909125'

Kotlin

externalNativeBuild {
        cmake {
            path = file("src/main/cpp/CMakeLists.txt")
            version = "3.22.1"
        }
    }
ndkVersion = "26.1.10909125"

Groovy

compileOptions {
   sourceCompatibility = JavaVersion.VERSION_17
   targetCompatibility = JavaVersion.VERSION_17
}

kotlinOptions {
   jvmTarget = JavaVersion.VERSION_17.toString()
}

Kotlin

compileOptions {
   sourceCompatibility = JavaVersion.VERSION_17
   targetCompatibility = JavaVersion.VERSION_17
}

kotlinOptions {
   jvmTarget = JavaVersion.VERSION_17.toString()
}

Groovy

composeOptions {
     kotlinCompilerExtensionVersion = '1.5.4'
}

packagingOptions {
    resources {
        excludes += '/META-INF/{AL2.0,LGPL2.1}' //for compose
    }
}

Kotlin

composeOptions {
     kotlinCompilerExtensionVersion = "1.5.4"
}

packaging {
    resources {
            excludes += "/META-INF/{AL2.0,LGPL2.1}" //for compose
    }
}

Groovy

flavorDimensions "version"
productFlavors {
   dev{
       applicationId "com.myproject.myproject.dev"
       minSdkVersion 27
       targetSdkVersion 37
       versionCode 1
       versionName "1.0.0"
       flavorDimensions "version"
       resValue "string", "app_name", "App Name dev"
       buildConfigField "String", "url", "\"https://testServer.com\""
  }
  pro{
      applicationId "com.myproject.myproject"
      minSdkVersion 27
      targetSdkVersion 34
      versionCode 1
      versionName "1.0.0"
      flavorDimensions "version"
      resValue "string", "app_name", "App Name"
      buildConfigField "String", "url", "\"https://liveServer.com\""
      signingConfig signingConfigs.release
  }
 }

Kotlin

flavorDimensions += "version"
productFlavors {
    create("dev") {
      applicationId = "com.myproject.myproject.dev"
      minSdk = 27
      targetSdk = 34
      versionCode = 1
      versionName = "1.0.0"
      dimension = "version"
      resValue("string", "app_name", "App Name dev")
      buildConfigField("String", "url", "\"https://testServer.com\"")
    }
    create("pro") {
      applicationId = "com.myproject.myproject"
      minSdk = 27
      targetSdk = 34
      versionCode = 1
      versionName = "1.0.0"
      dimension = "version"
      resValue("string", "app_name", "App Name")
      buildConfigField("String", "url", "\"https://liveServer.com\"")
      signingConfig = signingConfigs.getByName("config")
    }
   }

Groovy

ext {
  activityVersion = '1.8.1'
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "androidx.activity:activity-ktx:$activityVersion"
}

Kotlin

val activityVersion by extra("1.8.1")

dependencies {
    implementation(fileTree(mapOf("dir" to "libs", "include" to listOf("*.jar"))))
    implementation("androidx.activity:activity-ktx:$activityVersion")
}

I hope you find the article useful. I hope that I helped you to find the basic code for the Gradle in one place, and don’t spend time for searching them. Let me know your opinion under the comments, feel free to report any issue. I will appreciate it if you let a clap, so, if I have your support to continue writing.

Next, you can check the Part 2 for this article that it shows the other Gradle files and Part 3, the new initialization way with Version Catalogs.

Migration from Groovy to Kotlin DSL Gradle (Part 2)

Migration Gradle Dependencies to Version Catalogs — libs.versions.toms (Part 3)

References:

Migrate your build configuration from Groovy to Kotlin | Android Studio | Android Developers

Kotlin DSL is Now the Default for New Gradle Builds

Gradle Kotlin DSL Primer

Kotlin DSL is Now the Default for New Gradle Builds