# Aggregating code coverage with JaCoCo from an application/distribution (Incubating) Sample

version 9.0.0

- Groovy DSL

- Kotlin DSL

| You can open this sample in an IDE that supports Gradle.

This sample shows how to aggregate code coverage across multiple Java subprojects using JaCoCo. The jacoco-report-aggregation plugin provides this ability when applied to the distribution project, such as an Android application or WAR subproject.

The project in this example contains three projects: `application`, `list` and `utilities`. All three projects apply the `jacoco` plugin, and `application` consumes both `list` and `utilities` on its implementation configuration. The `application` subproject is the final distribution of this software project, and applies `jacoco-report-aggregation` to perform the code coverage aggregation.

| The Test Report Aggregation plugin does not currently work with the `com.android.application` plugin.

application/build.gradle.kts

    plugins {
        id("myproject.java-conventions")
        application
        id("jacoco-report-aggregation") (1)
    }

    dependencies {
        implementation(project(":list"))
        implementation(project(":utilities"))
    }

    application {
        mainClass = "org.gradle.sample.Main"
    }

    tasks.check {
        dependsOn(tasks.named<JacocoReport>("testCodeCoverageReport")) (2)
    }

application/build.gradle

    plugins {
        id 'myproject.java-conventions'
        id 'application'
        id 'jacoco-report-aggregation' (1)
    }

    dependencies {
        implementation project(':list')
        implementation project(':utilities')
    }

    application {
        mainClass = 'org.gradle.sample.Main'
    }

    tasks.named('check') {
        dependsOn tasks.named('testCodeCoverageReport', JacocoReport) (2)
    }

The `application` project requires no additional configuration if the `jvm-test-suite` plugin is present.

1 | Apply the `jacoco-report-aggregation` plugin
2 | Optional: make JaCoCo aggregate report generation part of the 'check' lifecycle phase

The report aggregation logic does not automatically inspect all subprojects for coverage data to aggregate. Instead, the direct and transitive project dependencies of the distribution project’s runtime classpath are selected for potential aggregation.

For the default test suite named 'test', no additional configuration is necessary. The aggregated reports and their backing tasks of type `JacocoReport` are synthesized based on the test suites existing in the `application` project. Test suites having identical `testType` properties will be aggregated.

Running the tests and generate the report:

    $ ./gradlew testCodeCoverageReport

    BUILD SUCCESSFUL
    25 actionable tasks: 25 executed

XML and HTML reports can now be found under `application/build/reports/jacoco/testCodeCoverageReport`.

For more information, see Testing in Java project chapter.