If you’re using a Kotlin as your Gradle DSL and wish to use spotless in your project, you can take the following steps. You’re using Kotlin as your Gradle DSL if your build file is build.gradle.kts.

Add Spotless Plugin

Most recent version can be found here.

plugins {
    kotlin("jvm") version "1.7.10"
    id("com.diffplug.spotless") version "6.7.2"
}

Configure Spotless + Plugin of Choice

When using Kotlin as your DSL, you need to change the documentation on GitHub to use method calls and double-quoted strings.

configure<com.diffplug.gradle.spotless.SpotlessExtension> {
    kotlin { ktlint() }
    kotlinGradle {
        target("*.gradle.kts")
        ktlint()
    }
}

Example build.gradle.kts

import org.jetbrains.kotlin.gradle.tasks.KotlinCompile

plugins {
    kotlin("jvm") version "1.7.10"
    id("com.diffplug.spotless") version "6.7.2"
}

group = "your.group.id"

version = "1.0-SNAPSHOT"

repositories { mavenCentral() }

dependencies {
    testImplementation(kotlin("test"))
}

configure<com.diffplug.gradle.spotless.SpotlessExtension> {
    kotlin { ktlint() }
    kotlinGradle {
        target("*.gradle.kts")
        ktlint()
    }
}

tasks.test { useJUnitPlatform() }

tasks.withType<KotlinCompile> { kotlinOptions.jvmTarget = "1.8" }

In this example, I use ktlint. You can view supported plugins here.

That’s it!