How to configure gradle sourcesets so that .groovy and .java files can be in one directory

This small snippet below makes it possible to have .groovy and .java files both in /src/main/java or /src/test/java:

sourceSets {
 //override default project structure to make it possible to have .groovy files in src/*/java
 main {
  groovy { srcDir 'src/main/java' }
  java { srcDirs = []}
 }
 test {
  groovy { srcDir 'src/test/java' }
  java { srcDirs = []}
 }
}