Migrating Build Configuration From Groovy to Kotlin for an Android Project

Domain-specific languages, or DSLs, are languages specialized for a specific part of an app. It is used to extract a part of the code to make it reusable and more understandable. As opposed to a function or a method, DSLs also change the way you use and write code.

To make a DSL means to change the syntax of that specific part of the code. In Kotlin, this is achieved by using lambda and extension functions, and expressions, to remove a lot of boilerplate code and hide the internal implementation from the user.

For example, I will take a newly created project and I will use the example to translate it from Groovy to Kotlin step by step.

1. The first thing we will do is change the file extension from .gradle to .gradle.kts

2. Changing plugins

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

3. Let's go to the android block and change the fields namespace и compileSdk:

namespace = "kz.azamat.androidlessoncoroutines"  
compileSdk = 33

4. Changing defaultConfig block:

defaultConfig {  
    applicationId = "kz.azamat.androidlessoncoroutines"  
    minSdk = 23  
    targetSdk = 33  
    versionCode = 1  
    versionName = "1.0"  
    testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"  
}

5. Changing for buildTypes block:

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

6. compileOptions will be changed to java and make a change for sourceCompatibility, targetCompatibility and for kotlinOptions:

java {  
    sourceCompatibility = JavaVersion.VERSION_1_8  
    targetCompatibility = JavaVersion.VERSION_1_8  
}  

kotlinOptions {  
    jvmTarget = "1.8"  
}

7. Finally change the dependency section:

dependencies {  
    implementation("androidx.core:core-ktx:1.7.0")  
    implementation("androidx.appcompat:appcompat:1.6.1")  
    implementation("com.google.android.material:material:1.9.0")  
    implementation("androidx.constraintlayout:constraintlayout:2.1.4")  
    testImplementation("junit:junit:4.13.2")  
    androidTestImplementation("androidx.test.ext:junit:1.1.5")  
    androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")  
}

Eventually, our code looks like this: