Integrations

Maven integration

By adding the plugin definition below to the <plugins> section in the pom.xml:

• The ktlint task is bound to the Maven verify lifecycle and will be executed each time the mvn verify is executed. It can also be executed with command mvn antrun:run@ktlint.
• The ktlint-format task is not bound to any other maven lifecycle. It can be executed with command mvn antrun:run@ktlint-format.

See cli usage for arguments that can be supplied to ktlint.

Adding plugin to pom.xml

...
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-antrun-plugin</artifactId>
    <version>3.1.0</version>
    <executions>
        <execution>
            <id>ktlint</id>
            <phase>verify</phase>
            <configuration>
            <target name="ktlint">
                <java taskname="ktlint" dir="${basedir}" fork="true" failonerror="true"
                    classpathref="maven.plugin.classpath" classname="com.pinterest.ktlint.Main">
                  <!-- Note: the JVM arg below is only required when running ktlint with Java 16+ in format mode.
                  <jvmarg value="--add-opens=java.base/java.lang=ALL-UNNAMED"/>
                  -->
                  <!-- see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information -->
                  <arg value="src/**/*.kt"/>
                </java>
            </target>
            </configuration>
            <goals>
                <goal>run</goal>
            </goals>
        </execution>
        <execution>
            <id>ktlint-format</id>
            <configuration>
            <target name="ktlint">
                <java taskname="ktlint" dir="${basedir}" fork="true" failonerror="true"
                    classpathref="maven.plugin.classpath" classname="com.pinterest.ktlint.Main">
                    <!-- Note: the JVM args below is only required when running ktlint with Java 16+ in format mode -->
                    <jvmarg value="--add-opens=java.base/java.lang=ALL-UNNAMED"/>
                    <!-- see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information -->
                    <arg value="-F"/>
                    <arg value="src/**/*.kt"/>
                </java>
            </target>
            </configuration>
            <goals>
                <goal>run</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>com.pinterest</groupId>
            <artifactId>ktlint</artifactId>
            <version>0.49.0</version>
        </dependency>
        <!-- additional 3rd party ruleset(s) can be specified here -->
    </dependencies>
</plugin>
...

Tip

If you want ktlint to run before code compilation takes place - change <phase>verify</phase> to <phase>validate</phase> (see Maven Build Lifecycle for more).

ktlint-maven-plugin

You might be interested to use the dedicated gantsign/ktlint-maven-plugin.

Gradle integration

jlleitschuh/ktlint-gradle

The jlleitschuh/ktlint-gradle Gradle plugin automatically creates check and format tasks for project Kotlin sources. It supports different kotlin plugins and Gradle build caching.

jeremymailen/kotlinter-gradle

The jeremymailen/kotlinter-gradle Gradle plugin features incremental build support, file reports, and *.kts source support.

diffplug/spotless

The diffplug/spotless Gradle plugin is a general-purpose formatting plugin which amongst many others also supports ktlint.

autostyle/autostyle

The autostyle/autostyle Gradle plugin is a general-purpose formatting plugin which amongst others also supports ktlint.

Custom Gradle integration

Custom Gradle integration with Groovy

Warning

It is recommended to use one of the Gradle plugins mentioned before.

The configuration below, defines following task:

• The ktlintCheck is bound to the Gradle check task. It can also be executed with command ./gradlew ktlintCheck.
• The ktlintFormat task is not bound to any other task. It can be executed with command ./gradlew ktlintFormat.

build.gradle

// kotlin-gradle-plugin must be applied for configuration below to work
// (see https://kotlinlang.org/docs/reference/using-gradle.html)

plugins {
    id 'java'
}

repositories {
    mavenCentral()
}

configurations {
    ktlint
}

dependencies {
    ktlint("com.pinterest:ktlint:0.49.0") {
        attributes {
            attribute(Bundling.BUNDLING_ATTRIBUTE, getObjects().named(Bundling, Bundling.EXTERNAL))
        }
    }
    // additional 3rd party ruleset(s) can be specified here
    // just add them to the classpath (e.g. ktlint 'groupId:artifactId:version') and 
    // ktlint will pick them up
}

tasks.register("ktlintCheck", JavaExec) {
    group = "verification"
    description = "Check Kotlin code style."
    classpath = configurations.ktlint
    mainClass = "com.pinterest.ktlint.Main"
    // see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information
    args "src/**/*.kt", "**.kts", "!**/build/**"
}

tasks.named("check") {
    dependsOn tasks.named("ktlintCheck")
}

tasks.register("ktlintFormat", JavaExec) {
    group = "formatting"
    description = "Fix Kotlin code style deviations."
    classpath = configurations.ktlint
    mainClass = "com.pinterest.ktlint.Main"
    jvmArgs "--add-opens=java.base/java.lang=ALL-UNNAMED"
    // see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information
    args "-F", "src/**/*.kt", "**.kts", "!**/build/**"
}

See Making your Gradle tasks incremental by Niklas Baudy on how to make tasks above incremental.

Custom Gradle integration with Kotlin DSL

Warning

It is recommended to use one of the Gradle plugins mentioned before.

The configuration below, defines following task:

• The ktlintCheck is bound to the Gradle check task. It can also be executed with command ./gradlew ktlintCheck.
• The ktlintFormat task is not bound to any other task. It can be executed with command ./gradlew ktlintFormat.

build.gradle.kts

val ktlint by configurations.creating

dependencies {
    ktlint("com.pinterest:ktlint:0.49.0") {
        attributes {
            attribute(Bundling.BUNDLING_ATTRIBUTE, objects.named(Bundling.EXTERNAL))
        }
    }
    // ktlint(project(":custom-ktlint-ruleset")) // in case of custom ruleset
}

val ktlintCheck by tasks.registering(JavaExec::class) {
    group = LifecycleBasePlugin.VERIFICATION_GROUP
    description = "Check Kotlin code style"
    classpath = ktlint
    mainClass.set("com.pinterest.ktlint.Main")
    // see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information
    args(
        "**/src/**/*.kt",
        "**.kts",
        "!**/build/**",
    )
}

tasks.check {
    dependsOn(ktlintCheck)
}

tasks.register<JavaExec>("ktlintFormat") {
    group = LifecycleBasePlugin.VERIFICATION_GROUP
    description = "Check Kotlin code style and format"
    classpath = ktlint
    mainClass.set("com.pinterest.ktlint.Main")
    jvmArgs("--add-opens=java.base/java.lang=ALL-UNNAMED")
    // see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information
    args(
        "-F",
        "**/src/**/*.kt",
        "**.kts",
        "!**/build/**",
    )
}

GNU Emacs integration

See whirm/flycheck-kotlin.

Vim integration

See w0rp/ale.

Mega-Linter integration

The Mega-Linter integrates 70+ linters in a single tool for CI, including ktlint activated out of the box

Other integration

Do you know any other integration with ktlint then please create a PR to add this integration to our documentation.