You do this similar to how you turn your main sources into a module:
by adding a `module-info.java` file to the corresponding source set (e.g. `integrationTests/java/module-info.java`).

You can find a full example that includes blackbox integration tests link:../samples/sample_java_modules_multi_project_with_integration_tests.html[here].

plugins {
    id 'java'
}

version = '1.0.2'
group = 'org.gradle.sample'

repositories {
    mavenCentral()
}

def integrationTest = sourceSets.create('integrationTest')

configurations[integrationTest.implementationConfigurationName].extendsFrom(configurations.testImplementation)
configurations[integrationTest.runtimeOnlyConfigurationName].extendsFrom(configurations.testRuntimeOnly)

tasks.named("test") {
    useJUnitPlatform()
}

    id 'com.myorg.java-conventions'
}
// end::plugins[]

def integrationTest = sourceSets.create('integrationTest')

configurations[integrationTest.implementationConfigurationName].extendsFrom(configurations.testImplementation)
configurations[integrationTest.runtimeOnlyConfigurationName].extendsFrom(configurations.testRuntimeOnly)

def integrationTestTask = tasks.register('integrationTest', Test) {
    testClassesDirs = integrationTest.output.classesDirs

}
// end::plugins[]

val integrationTest by sourceSets.creating

configurations[integrationTest.implementationConfigurationName].extendsFrom(configurations.testImplementation.get())
configurations[integrationTest.runtimeOnlyConfigurationName].extendsFrom(configurations.testRuntimeOnly.get())

val integrationTestTask = tasks.register<Test>("integrationTest") {
    testClassesDirs = integrationTest.output.classesDirs

    }

    @Test
    fun `can use integrationTest configuration to define dependencies`() {
        buildFile.appendText("""
            dependencies {
                integrationTestImplementation("junit:junit:4.13")
            }
        """)

        testProjectDir.newFolder("src", "integrationTest", "java", "com", "myorg")
        testProjectDir.newFile("src/integrationTest/java/com/myorg/SomeIntegrationTest.java").writeText("""

                classpath = sourceSets.integrationTest.runtimeClasspath
            }

            task jacocoIntegrationTestReport(type: JacocoReport) {
                executionData integrationTest
                sourceSets sourceSets.main
            }

            task jacocoIntegrationTestCoverageVerification(type: JacocoCoverageVerification) {
                executionData integrationTest

        outputContains("""
--------------------------------------------------
Variant testResultsElementsForIntegrationTest (i)
--------------------------------------------------
Directory containing binary results of running tests for the integrationTest Test Suite's integrationTest target.

Capabilities

plugins {
    id 'java'
}

version = '1.0.2'
group = 'org.gradle.sample'

repositories {
    mavenCentral()
}

def integrationTest = sourceSets.create('integrationTest')

configurations[integrationTest.implementationConfigurationName].extendsFrom(configurations.testImplementation)
configurations[integrationTest.runtimeOnlyConfigurationName].extendsFrom(configurations.testRuntimeOnly)

tasks.named('test') {
    useJUnitPlatform()
}

    archiveClassifier = "integration-tests"
    from(integrationTest.output)
}

val integrationTestTask = tasks.register<Test>("integrationTest") {
    description = "Runs integration tests."
    group = "verification"
    useJUnitPlatform()

    testClassesDirs = integrationTest.output.classesDirs

    description = "Runs integration tests."
    group = "verification"
    useJUnitPlatform()

    testClassesDirs = integrationTest.output.classesDirs
    classpath = configurations[integrationTest.runtimeClasspathConfigurationName] + integrationTest.output

    shouldRunAfter(tasks.test)
}

tasks.check {
    dependsOn(integrationTestTask)
}

dependencies {