Run detekt using the Detekt Gradle Plugin

Detekt requires Gradle 6.7.1 or higher. We, however, recommend using the version of Gradle that is listed in this table.

Available plugin tasks

The Detekt Gradle Plugin will generate multiple tasks:

• detekt - Runs a detekt analysis and complexity report on your source files. Configure the analysis inside the detekt closure.
  • By default, the standard rule set without any ignore list is executed on sources files located in src/main/java, src/test/java, src/main/kotlin and src/test/kotlin.
  • Reports are automatically generated in xml, html, txt, md, and sarif format and can be found in build/reports/detekt/detekt.[xml|html|txt|md|sarif] respectively.
  • Please note that the detekt task is automatically run when executing gradle check.
  • You may specify Gradle task CLI option for auto correction, such as gradle detekt --auto-correct.
• detektGenerateConfig - Generates a default detekt configuration file into your project directory.
• detektBaseline - Similar to detekt, but creates a code smell baseline. Further detekt runs will only feature new smells not in this list.

In addition to these standard tasks, the plugin will also generate a set of experimental tasks that have type resolution enabled. This happens for both, pure JVM projects and Android projects that have the Android Gradle Plugin applied:

• detektMain - Similar to detekt, but runs only on the main source set (Android: all production source sets)
• detektTest - Similar to detekt, but runs only on the test source set (Android: all JVM and Android Test source sets)
• detektBaselineMain - Similar to detektBaseline, but creates a baseline only for the main source set (Android: multiple baselines for all production source sets)
• detektBaselineTest - Similar to detektBaseline, but creates a baseline only for the test source set (Android: multiple baselines for all JVM and Android Test source sets)
• Android-only: detekt<Variant> - Similar to detekt, but runs only on the specific (test) build variant
• Android-only: detektBaseline<Variant> - Similar to detektBaseline, but creates a baseline only for the specific (test) build variant

Baseline files that are generated for these specific source sets / build variants contain the name of the source set / the name of the build variant in their name, unless otherwise configured, such as detekt-main.xml or detekt-productionDebug.xml.

If both, a detekt-main.xml and a detekt.xml baseline file exists in place, the more specific one - detekt-main.xml - takes precedence when the detektMain task is executed, likewise for Android variant-specific baseline files.

NOTE: When analyzing Android projects that make use of specific code generators, such as Data Binding, Kotlin synthetic view accessors or else, you might see warnings output while Detekt runs. This is due to the inability to gather the complete compile classpath from the Android Gradle Plugin (upstream ticket) and can safely be ignored.

Use the Groovy or Kotlin DSL of Gradle to apply the Detekt Gradle Plugin. You can further configure the Plugin using the detekt closure as described here.

Configuration

Using the plugins DSL:

Groovy DSL

plugins {
    id "io.gitlab.arturbosch.detekt" version "1.23.3"
}

repositories {
    mavenCentral()
}

Kotlin DSL

plugins {
    id("io.gitlab.arturbosch.detekt") version "1.23.3"
}

repositories {
    mavenCentral()
}

Using legacy plugin application (buildscript{}):

Groovy DSL

buildscript {
    repositories {
        gradlePluginPortal()
    }
    dependencies {
        classpath "io.gitlab.arturbosch.detekt:detekt-gradle-plugin:1.23.3"
    }
}

apply plugin: "io.gitlab.arturbosch.detekt"

repositories {
    mavenCentral()
}

Kotlin DSL

buildscript {
    repositories {
        gradlePluginPortal()
    }
    dependencies {
        classpath("io.gitlab.arturbosch.detekt:detekt-gradle-plugin:1.23.3")
    }
}

apply(plugin = "io.gitlab.arturbosch.detekt")

repositories {
    mavenCentral()
}

Configuration for Android projects

When using Android make sure to have detekt configured in the app/module level build.gradle file.

You can configure the plugin in the same way as indicated above.

Groovy DSL

buildscript {
    repositories {
        google()
        mavenCentral()
        gradlePluginPortal()
    }
    dependencies {
        classpath "com.android.tools.build:gradle:<agp_version>"
    }
}

plugins {
    id "com.android.application"
    id "org.jetbrains.kotlin.android" version "<kotlin_version>"
    id "io.gitlab.arturbosch.detekt" version "1.23.3"
}

repositories {
    mavenCentral()
}

Kotlin DSL

buildscript {
    repositories {
        google()
        mavenCentral()
        gradlePluginPortal()
    }
    dependencies {
        classpath("com.android.tools.build:gradle:<agp_version>")
    }
}

plugins {
    id("com.android.application")
    kotlin("android") version "<kotlin_version>"
    id("io.gitlab.arturbosch.detekt") version "1.23.3"
}

repositories {
    mavenCentral()
}

Options for detekt configuration closure

Groovy DSL

detekt {
    // Version of Detekt that will be used. When unspecified the latest detekt
    // version found will be used. Override to stay on the same version.
    toolVersion = "1.23.3"
    
    // The directories where detekt looks for source files. 
    // Defaults to `files("src/main/java", "src/test/java", "src/main/kotlin", "src/test/kotlin")`.
    source = files(
        "src/main/kotlin",
        "gensrc/main/kotlin"
    )
    
    // Builds the AST in parallel. Rules are always executed in parallel. 
    // Can lead to speedups in larger projects. `false` by default.
    parallel = false
    
    // Define the detekt configuration(s) you want to use. 
    // Defaults to the default detekt configuration.
    config = files("path/to/config.yml")
    
    // Applies the config files on top of detekt's default config file. `false` by default.
    buildUponDefaultConfig = false
    
    // Turns on all the rules. `false` by default.
    allRules = false
    
    // Specifying a baseline file. All findings stored in this file in subsequent runs of detekt.
    baseline = file("path/to/baseline.xml")
    
    // Disables all default detekt rulesets and will only run detekt with custom rules
    // defined in plugins passed in with `detektPlugins` configuration. `false` by default.
    disableDefaultRuleSets = false
    
    // Adds debug output during task execution. `false` by default.
    debug = false                                         
    
    // If set to `true` the build does not fail when the
    // maxIssues count was reached. Defaults to `false`.
    ignoreFailures = false
    
    // Android: Don't create tasks for the specified build types (e.g. "release")
    ignoredBuildTypes = ["release"]
    
    // Android: Don't create tasks for the specified build flavor (e.g. "production")
    ignoredFlavors = ["production"]
    
    // Android: Don't create tasks for the specified build variants (e.g. "productionRelease")
    ignoredVariants = ["productionRelease"]
    
    // Specify the base path for file paths in the formatted reports. 
    // If not set, all file paths reported will be absolute file path.
    basePath = projectDir
}

Kotlin DSL

detekt {
    // Version of Detekt that will be used. When unspecified the latest detekt
    // version found will be used. Override to stay on the same version.
    toolVersion = "1.23.3"
    
    // The directories where detekt looks for source files. 
    // Defaults to `files("src/main/java", "src/test/java", "src/main/kotlin", "src/test/kotlin")`.
    source = files("src/main/java", "src/main/kotlin")     
    
    // Builds the AST in parallel. Rules are always executed in parallel. 
    // Can lead to speedups in larger projects. `false` by default.
    parallel = false
    
    // Define the detekt configuration(s) you want to use. 
    // Defaults to the default detekt configuration.
    config = files("path/to/config.yml")
    
    // Applies the config files on top of detekt's default config file. `false` by default.
    buildUponDefaultConfig = false
    
    // Turns on all the rules. `false` by default.
    allRules = false
    
    // Specifying a baseline file. All findings stored in this file in subsequent runs of detekt.
    baseline = file("path/to/baseline.xml")
    
    // Disables all default detekt rulesets and will only run detekt with custom rules
    // defined in plugins passed in with `detektPlugins` configuration. `false` by default.
    disableDefaultRuleSets = false
    
    // Adds debug output during task execution. `false` by default.
    debug = false                                         
    
    // If set to `true` the build does not fail when the
    // maxIssues count was reached. Defaults to `false`.
    ignoreFailures = false
    
    // Android: Don't create tasks for the specified build types (e.g. "release")
    ignoredBuildTypes = listOf("release")
    
    // Android: Don't create tasks for the specified build flavor (e.g. "production")
    ignoredFlavors = listOf("production")
    
    // Android: Don't create tasks for the specified build variants (e.g. "productionRelease")
    ignoredVariants = listOf("productionRelease")
    
    // Specify the base path for file paths in the formatted reports. 
    // If not set, all file paths reported will be absolute file path.
    basePath = projectDir
}

Reports

Report output can be customized for each task. The DSL is the same in both Groovy and Kotlin:

tasks.named("detekt").configure {
    reports {
        // Enable/Disable XML report (default: true)
        xml.required.set(true)
        xml.outputLocation.set(file("build/reports/detekt.xml"))
        // Enable/Disable HTML report (default: true)
        html.required.set(true)
        html.outputLocation.set(file("build/reports/detekt.html"))
        // Enable/Disable TXT report (default: true)
        txt.required.set(true)
        txt.outputLocation.set(file("build/reports/detekt.txt"))
        // Enable/Disable SARIF report (default: false)
        sarif.required.set(true)
        sarif.outputLocation.set(file("build/reports/detekt.sarif"))
        // Enable/Disable MD report (default: false)
        md.required.set(true)
        md.outputLocation.set(file("build/reports/detekt.md"))
        custom {
            // The simple class name of your custom report.
            reportId = "CustomJsonReport"
            outputLocation.set(file("build/reports/detekt.json"))
        }
    }
}

Using Type Resolution

Type resolution is experimental and works only for predefined tasks listed above or when implementing a custom detekt task with the classpath and jvmTarget properties present.

jdkHome is also available as an input. When this is unset, analysis is performed using the JDK classes of the JDK that Gradle is running with (shown by the ./gradlew --version command). This can be an issue if the Gradle JDK and the project JDK doesn't match e.g. if Gradle runs under Java 8 but the project uses classes only available in Java 9 or higher. Setting jdkHome to the Java 9 JDK path will allow for more correct analysis.

jdkHome and jvmTarget are set automatically when applying a toolchain using either java or kotlin.

More information on type resolution are available on the type resolution page.

Groovy DSL

tasks.withType(io.gitlab.arturbosch.detekt.Detekt).configureEach {
    jvmTarget = '1.8'
    jdkHome.set(file('path/to/jdkHome'))
}
tasks.withType(io.gitlab.arturbosch.detekt.DetektCreateBaselineTask).configureEach {
    jvmTarget = '1.8'
    jdkHome.set(file('path/to/jdkHome'))
}

Kotlin DSL

tasks.withType<io.gitlab.arturbosch.detekt.Detekt>().configureEach {
    this.jvmTarget = "1.8"
    jdkHome.set(file("path/to/jdkHome"))
}
tasks.withType<io.gitlab.arturbosch.detekt.DetektCreateBaselineTask>().configureEach {
    this.jvmTarget = "1.8"
    jdkHome.set(file("path/to/jdkHome"))
}

Leveraging Gradle's SourceTask - Excluding and including source files

A detekt task extends the Gradle SourceTask to be only scheduled when watched source files are changed. It also allows to match files that should be excluded from the analysis. To do this introduce a query on detekt tasks and define include and exclude patterns outside the detekt closure:

Groovy DSL

detekt {
    ...
}

tasks.withType(io.gitlab.arturbosch.detekt.Detekt).configureEach {
    // include("**/special/package/**") // only analyze a sub package inside src/main/kotlin
    exclude("**/special/package/internal/**") // but exclude our legacy internal package
}

tasks.withType(io.gitlab.arturbosch.detekt.DetektCreateBaselineTask).configureEach {
    // include("**/special/package/**") // only analyze a sub package inside src/main/kotlin
    exclude("**/special/package/internal/**") // but exclude our legacy internal package
}

Kotlin DSL

detekt {
    ...
}

tasks.withType<io.gitlab.arturbosch.detekt.Detekt>().configureEach {
    // include("**/special/package/**") // only analyze a sub package inside src/main/kotlin
    exclude("**/special/package/internal/**") // but exclude our legacy internal package
}

tasks.withType<io.gitlab.arturbosch.detekt.DetektCreateBaselineTask>().configureEach {
    // include("**/special/package/**") // only analyze a sub package inside src/main/kotlin
    exclude("**/special/package/internal/**") // but exclude our legacy internal package
}

Defining custom detekt task

Custom tasks for alternative configurations or different source sets can be defined by creating a custom task that uses the type Detekt.

Groovy DSL

tasks.register(name: myDetekt, type: io.gitlab.arturbosch.detekt.Detekt) {
    description = "Runs a custom detekt build."
    setSource(files("src/main/kotlin", "src/test/kotlin"))
    config.setFrom(files("$rootDir/config.yml"))
    debug = true
    reports {
        xml {
            destination = file("build/reports/mydetekt.xml")
        }
        html.destination = file("build/reports/mydetekt.html")
    }
    include '**/*.kt'
    include '**/*.kts'
    exclude 'resources/'
    exclude 'build/'
}

Kotlin DSL

tasks.register<io.gitlab.arturbosch.detekt.Detekt>("myDetekt") {
    description = "Runs a custom detekt build."
    setSource(files("src/main/kotlin", "src/test/kotlin"))
    config.setFrom(files("$rootDir/config.yml"))
    debug = true
    reports {
        xml {
            destination = file("build/reports/mydetekt.xml")
        }
        html.destination = file("build/reports/mydetekt.html")
    }
    include("**/*.kt")
    include("**/*.kts")
    exclude("resources/")
    exclude("build/")
}

Disabling detekt from the check task

Detekt tasks by default are verification tasks. They get executed whenever the Gradle check task gets executed. This aligns with the behavior of other code analysis plugins for Gradle.

If you are adding detekt to an already long running project you may want to increase the code quality incrementally and therefore exclude detekt from the check task.

Groovy DSL

check.configure {
    dependsOn = dependsOn.findAll { it.name != 'detekt' }
}

Kotlin DSL

tasks.named("check").configure {
    this.setDependsOn(this.dependsOn.filterNot {
        it is TaskProvider<*> && it.name == "detekt"
    })
}

Instead of disabling detekt for the check task, you may want to increase the build failure threshold in the configuration file.

Integrating detekt inside your IntelliJ IDEA

detekt comes with an IntelliJ Plugin that you can install directly from the IDE. The plugin offers warning highlight directly inside the IDE as well as support for code formatting.

The source code of the plugin is available here: detekt/detekt-intellij-plugin