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="${basedir}" fork="true" failonerror="true"
                    classpathref="maven.plugin.classpath" classname="com.pinterest.ktlint.Main">
                    <arg value="src/**/*.kt"/>
                    <!-- see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information -->
                </java>
            </target>
            </configuration>
            <goals>
                <goal>run</goal>
            </goals>
        </execution>
        <execution>
            <id>ktlint-format</id>
            <configuration>
            <target name="ktlint">
                <java taskname="ktlint" dir="${basedir}" fork="true" failonerror="true"
                    classpathref="maven.plugin.classpath" classname="com.pinterest.ktlint.Main">
                    <arg value="-F"/>
                    <arg value="src/**/*.kt"/>
                    <!-- see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information -->
                </java>
            </target>
            </configuration>
            <goals>
                <goal>run</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>com.pinterest</groupId>
            <artifactId>ktlint</artifactId>
            <version>0.48.0</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 ktlint is bound to the Gradle check task. It can also be executed with command gradle ktlint.
• The ktlint-format task is not bound to any other task. It can be executed with command gradle ktlintFormat.

build.gradle

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

apply plugin: 'java'

repositories {
    mavenCentral()
}

configurations {
    ktlint
}

dependencies {
    ktlint("com.pinterest:ktlint:0.48.0") {
        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
}

task ktlint(type: JavaExec, group: "verification") {
    description = "Check Kotlin code style."
    classpath = configurations.ktlint
    mainClass.set("com.pinterest.ktlint.Main")
    args "src/**/*.kt"
    // see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information
}
check.dependsOn ktlint

task ktlintFormat(type: JavaExec, group: "formatting") {
    description = "Fix Kotlin code style deviations."
    classpath = configurations.ktlint
    mainClass.set("com.pinterest.ktlint.Main")
    args "-F", "src/**/*.kt"
    // see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information
}

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 ktlint is bound to the Gradle check task. It can also be executed with command gradle ktlint.
• The ktlint-format task is not bound to any other task. It can be executed with command gradle ktlintFormat.

build.gradle.kts

val ktlint by configurations.creating

dependencies {
    ktlint("com.pinterest:ktlint:0.48.0") {
        attributes {
            attribute(Bundling.BUNDLING_ATTRIBUTE, objects.named(Bundling.EXTERNAL))
        }
    }
    // ktlint(project(":custom-ktlint-ruleset")) // in case of custom ruleset
}

val outputDir = "${project.buildDir}/reports/ktlint/"
val inputFiles = project.fileTree(mapOf("dir" to "src", "include" to "**/*.kt"))

val ktlintCheck by tasks.creating(JavaExec::class) {
    inputs.files(inputFiles)
    outputs.dir(outputDir)

    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 = listOf("src/**/*.kt")
}

val ktlintFormat by tasks.creating(JavaExec::class) {
    inputs.files(inputFiles)
    outputs.dir(outputDir)

    description = "Fix Kotlin code style deviations."
    classpath = ktlint
    mainClass.set("com.pinterest.ktlint.Main")
    // see https://pinterest.github.io/ktlint/install/cli/#command-line-usage for more information
    args = listOf("-F", "src/**/*.kt")
}

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.