Optimize Gradle Task Management with Kotlin DSL and buildSrc

// build.gradle.kts (projet racine)
plugins {
    base // Appliqué au projet racine
}

allprojects {
    group = "com.example"
    version = "1.0.0"

    repositories {
        mavenCentral()
    }

    tasks.withType<org.gradle.api.tasks.testing.Test> {
        useJUnitPlatform() // Configuration commune des tests pour tous les projets
    }
}

subprojects {
    apply(plugin = "java")
    apply(plugin = "org.jetbrains.kotlin.jvm")

    dependencies {
        implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
    }

}

----
----
init {
    group = "verification"
    description = "Opens a test report in Firefox."
    dependsOn("check") // Assure que les rapports sont générés
}

@get:Input
abstract var reportPath: String

@TaskAction
fun openReport() {
    val separator = File.separator
    val reportFile = project.layout.projectDirectory.asFile.toPath()
        .resolve(reportPath.replace("/", separator))
        .toAbsolutePath()
        .toFile()

    if (!reportFile.exists()) {
        logger.warn("Report file does not exist: $reportFile. Ensure 'check' ran.")
        return
    }

    project.exec {
        commandLine("firefox", "--new-tab", reportFile.absolutePath)
    }
    logger.lifecycle("Opened test report: ${reportFile.absolutePath}")
}
----

## }

\=== Concrete Implementations

These classes inherit from the abstract task and define the specific report path.

## [source,kotlin]

package com.yourpackage

abstract class ReportUnitTestsTask : OpenTestReportTask() init { description = "Opens the unit test report in Firefox. reportPath = "build/reports/tests/test/index.html } }

package com.yourpackage

## abstract class ReportFunctionalTestsTask : OpenTestReportTask() { init { description = "Opens the functional test report in Firefox." reportPath = "build/reports/tests/functionalTest/index.html" } }

\=== Recording of Tasks

In the`build.gradle.kts`of your root project :

## [source,kotlin]

## tasks.register\<com.yourpackage.ReportUnitTestsTask\>("reportTests") {} tasks.register\<com.yourpackage.ReportFunctionalTestsTask\>("reportFunctionalTests") {}

\=== UML Diagram of Reporting Tasks (PlantUML Code)

Copy the code below and paste it into a tool that supports PlantUML.

## [source,plantuml]

@startuml skinparam handwritten true skinparam monochrome true

abstract class DefaultTask { }

abstract class Exec { \+ commandLine(args: String...) \+ exec() }

abstract class OpenTestReportTask extends DefaultTask { \+ group: String = "verification \+ description: String \+ dependsOn("check") \+ abstract reportPath: String \+ openReport() : void }

abstract class AbstractJbakeExecTask extends Exec { \+ group: String = "verification \+ description: String \+ dependsOn("check") \+ abstract reportRelativePath: String \+ exec() : void }

class ReportUnitTestsTask extends OpenTestReportTask { \+ reportPath: String = "build/reports/tests/test/index.html }

class ReportFunctionalTestsTask extends OpenTestReportTask { \+ reportPath: String = "build/reports/tests/functionalTest/index.html }

class ReportJbakeTestsTask extends AbstractJbakeExecTask { \+ reportRelativePath: String = "build/reports/tests/test/index.html }

class ReportJbakeFunctionalTestsTask extends AbstractJbakeExecTask { \+ reportRelativePath: String = "build/reports/tests/functionalTest/index.html }

OpenTestReportTask \<-- ReportUnitTestsTask OpenTestReportTask <-- ReportFunctionalTestsTask

AbstractJbakeExecTask \<-- ReportJbakeTestsTask AbstractJbakeExecTask \<-- ReportJbakeFunctionalTestsTask

DefaultTask \<|-- OpenTestReportTask Execute \<|-- AbstractJbakeExecTask DefaultTask \<|-- Exec

## @enduml

\== Abstract Task`AbstractJbakeExecTask`(inheriting from`Exec`)

If your task mainly consists of executing an external command with variable arguments, inherit directly from**Exec**is more direct.

## [source,kotlin]

package com.yourpackage

import org.gradle.api.tasks.Exec import org.gradle.api.tasks.Input import java.io.File

abstract class AbstractJbakeExecTask : Exec() {

----

init { group = "verification" description = "Opens a Jbake project report in Firefox." dependsOn("check") }

@get:Input abstract var reportRelativePath: String

override fun exec() { val separator = File.separator val reportFile = project.layout.projectDirectory.asFile.toPath() .resolve(reportRelativePath.replace("/", separator)) .toAbsolutePath() .toFile()

if (!reportFile.exists()) { logger.warn("Report file does not exist: $reportFile. Ensure 'check' ran.") return }

commandLine("firefox", "--new-tab", reportFile.absolutePath) logger.lifecycle("Attempting to open report: ${reportFile.absolutePath}") super.exec() // Appelle la méthode exec() de la super-classe Exec }

## }

Concrete Implementations for`Exec`

## [source,kotlin]

package com.yourpackage

abstract class ReportJbakeTestsTask : AbstractJbakeExecTask() {} init { description = "Opens the Jbake unit test report in Firefox. reportRelativePath = "build/reports/tests/test/index.html } }

package com.yourpackage

abstract class ReportJbakeFunctionalTestsTask : AbstractJbakeExecTask() { init { description = "Opens the functional test report in Firefox." reportRelativePath = "build/reports/tests/functionalTest/index.html" } }

\== Visibility of Tasks`buildSrc`

The tasks and classes you define in**buildSrc**are :

***Visible and usable**for all the projects in your main build (root and subprojects). That's why you can use`com.yourpackage.ReportUnitTestsTask`in`allprojects { ... }`. ***Non-executable**directly as buildSrc tasks (for example,`gradle :buildSrc:reportTests`it would not work if the task is not specifically recorded in`buildSrc/build.gradle.kts`).`buildSrc`is a compilation module, not an executable application module for these main build tasks.

\=== Run a report for tests of`buildSrc`himself

Si `buildSrc`has its own tests and generates reports, you can record a reporting task directly in`buildSrc/build.gradle.kts`:

python import sys

def main(): data = sys.stdin.read() sys.stdout.write(data)

if __name__ == '__main__': main()

plugins { `kotlin-jvm` }

repositories { mavenCentral() }

tasks.withType<Test> { useJUnitPlatform() reports.html.outputLocation.set(layout.buildDirectory.dir("reports/tests")) }

import com.yourpackage.ReportJbakeTestsTask // Import your task class

## tasks.register<ReportJbakeTestsTask>("reportBuildSrcTests") { // The path is already defined in the class, it will point to the buildSrc reports }

You will then be able to run:`./gradlew :buildSrc:test`followed by`./gradlew :buildSrc:reportBuildSrcTests`.

By adopting these practices, you will build Gradle build systems in Kotlin DSL that are not only powerful, but also incredibly modular, maintainable, and easy to understand.