Gradle - add dependency to tests of another module

Following the approach from sakis, this should be the configuration you need to get the tests available from another project in the Android platform (done for debug variant). Shared module:

task jarTests(type: Jar, dependsOn: "assembleDebugUnitTest") {
    classifier = 'tests'
    from "$buildDir/intermediates/classes/test/debug"
}
configurations {
    unitTestArtifact
}
artifacts {
    unitTestArtifact jarTests
}

Your module:

dependencies {
    testCompile project(path: ":libName", configuration: "unitTestArtifact")
}

I know it's kinda an old question but the solution mentioned in the following blog solves the problem very nicely and is not a sort of hack or a temporary workaround: Shared test sources in Gradle multi-module project

It works something like this:

// in your module's build.gradle file that needs tests from another module
dependencies {
    testCompile project(path: ':path.to.project', configuration: 'test')
}

Also you should note that in the very last paragraph he mentioned that you need to enable Create separate module per source set in IntelliJ settings. But it works fine without using that option too. Probably due to changes in the recent IntelliJ versions.

EDIT: IntelliJ recognizes this fine as of 2020.x versions.

There's a couple of approaches solving the problem of importing test classes in this article. https://softnoise.wordpress.com/2014/09/07/gradle-sub-project-test-dependencies-in-multi-project-builds/ The one I used is:

code in shared module:

task jarTest (type: Jar) {
    from sourceSets.test.output
    classifier = 'test'
}

configurations {
    testOutput
}

artifacts {
    testOutput jarTest
}

code in module depending on the shared module: dependencies{ testCompile project(path: ':common', configuration: 'testOutput') }

And there seems to be a plugin for it as well! https://plugins.gradle.org/plugin/com.github.hauner.jarTest/1.0

The solution mentioned by droidpl for Android + Kotlin looks like this:

task jarTests(type: Jar, dependsOn: "assembleDebugUnitTest") {
    getArchiveClassifier().set('tests')
    from "$buildDir/tmp/kotlin-classes/debugUnitTest"
}

configurations {
    unitTestArtifact
}

artifacts {
    unitTestArtifact jarTests
}

Gradle for project that is going to use dependencies:

testImplementation project(path: ':shared', configuration: 'unitTestArtifact')