gradle

Gradle Build System

Rule 1: Version Catalog is the only place for versions

# gradle/libs.versions.toml — single source of truth
[versions]
agp = "8.5.2"
kotlin = "2.0.21"
ksp = "2.0.21-1.0.25"

[libraries]
androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }

[plugins]
android-application = { id = "com.android.application", version.ref = "agp" }
kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }

// ✅ Use catalog aliases everywhere — never hardcode versions
implementation(libs.androidx.core.ktx)
plugins { alias(libs.plugins.android.application) }

// ❌ Hardcoded versions anywhere in build files
implementation("androidx.core:core-ktx:1.13.1")

Rule 2: Convention Plugins for multi-module consistency

// buildSrc/src/main/kotlin/AndroidLibraryConventionPlugin.kt
class AndroidLibraryConventionPlugin : Plugin<Project> {
    override fun apply(target: Project) = with(target) {
        pluginManager.apply("com.android.library")
        pluginManager.apply("org.jetbrains.kotlin.android")

        extensions.configure<LibraryExtension> {
            compileSdk = 35
            defaultConfig.minSdk = 24
            compileOptions {
                sourceCompatibility = JavaVersion.VERSION_17
                targetCompatibility = JavaVersion.VERSION_17
            }
        }
    }
}

// buildSrc/build.gradle.kts
plugins { `kotlin-dsl` }
dependencies {
    implementation(libs.android.gradlePlugin)
    implementation(libs.kotlin.gradlePlugin)
}

// Any feature module build.gradle.kts
plugins {
    id("convention.android.library")   // one line instead of 20
}

Rule 3: Build variants for environments

// ✅ Product flavors for different environments
android {
    flavorDimensions += "environment"

    productFlavors {
        create("dev") {
            dimension = "environment"
            applicationIdSuffix = ".dev"
            versionNameSuffix = "-dev"
            buildConfigField("String", "BASE_URL", "\"https://dev-api.myapp.com/\"")
        }
        create("staging") {
            dimension = "environment"
            applicationIdSuffix = ".staging"
            versionNameSuffix = "-staging"
            buildConfigField("String", "BASE_URL", "\"https://staging-api.myapp.com/\"")
        }
        create("prod") {
            dimension = "environment"
            buildConfigField("String", "BASE_URL", "\"https://api.myapp.com/\"")
        }
    }
}
// Results in: devDebug, devRelease, stagingDebug, stagingRelease, prodDebug, prodRelease