Gradle configuration for sharing code between several test source sets of a java project.

testSupport.gradle

configurations {
    // Create the configuration we will use to refer to our sources.
    testSupport.extendsFrom compile
}
 
sourceSets {
    // Creates two configurations (testSupportCompile, testSupportRuntime) we will ignore.
    testSupport {
        // We will at least need access to our main sourceSet and all dependencies that are declared for our configuration.
        compileClasspath += sourceSets.main.output + configurations.testSupport
    }
}
 
// Define a task to create a jar out of our sources.
task testSupportJar(type: Jar) {
    from sourceSets.testSupport.output
    classifier 'testSupport'
}
 
artifacts {
    // Expose the output of our Jar-Task as an artifact so other project can depend on it.
    testSupport testSupportJar
}