IssueTracker

I used to be able to reference java files located in libaray module dependencies in my app tests. However since Android Gradle Plugin 3.1.1 this is causing an error on build.

This error seems to be caused by the Android Gradle plugin 3.1.1 and not Gradle 4.4 as if I use Gradle 4.4 and Android Gradle plugin 3.0.0 it returns to a successful build.

Studio Build:
Version of Gradle Plugin: 3.1.1
Version of Gradle: 4.4
Version of Java: 1.8.0_151-b12
OS:     Mac OS X 10.13.3

Steps to Reproduce:
1. Create a Android app with one library module
2. Add a java class in the tests java directory to the library module
3. Include the library's java class into the app module via sourceSets

sourceSets {
    test {
        java.srcDirs += RELATIVE_PATH_TO_LIBRARY_MODULE_JAVA_FILE
    }
}

4. Build and a build error:

Lint infrastructure error Caused by: java.lang.reflect.InvocationTargetException

Caused by:

Caused by: java.lang.IllegalArgumentException: trying to add non-existing file to classpath: ....java



Link to stackoverflow question:
https://stackoverflow.com/questions/49860981/adding-test-sourcesets-has-stopped-working-in-android-gradle-plugin-3-1-1

Link to Gradle scan from test project described above:
https://scans.gradle.com/s/c7yagwqy45hfs