improve test-only-groovy to not rely on an existing outer module

Author: lostiniceland

libs/groovylib/src/mill/groovylib/JavaMavenModuleWithGroovyTests.scala

@@ -0,0 +1,16 @@
+package mill.groovylib
+
+import mill.*
+import mill.javalib.{JavaModule, MavenModule}
+
+/**
+ * Convenience trait for projects using Java for production and Groovy for tests in a Maven setup
+ */
+trait JavaMavenModuleWithGroovyTests extends JavaModule with MavenModule {
+
+  trait GroovyMavenTests extends JavaTests with MavenTests with GroovyModule {
+    private def groovyTestSources = Task.Sources(moduleDir / "src" / testModuleName / "groovy")
+    override def sources: T[Seq[PathRef]] = super[MavenTests].sources() ++ groovyTestSources()
+    override def resources: T[Seq[PathRef]] = super[MavenTests].resources()
+  }
+}

libs/groovylib/src/mill/groovylib/TestGroovyMavenModule.scala

@@ -4,6 +4,10 @@ export mill.javalib.DepSyntax
 
 export mill.javalib.Dep
 
+export mill.javalib.JavaModule
+
+export mill.javalib.MavenModule
+
 export mill.javalib.TestModule
 
 export mill.javalib.PublishModule

libs/groovylib/src/mill/groovylib/exports.scala

@@ -1,7 +1,5 @@
 package jointcompile
 
-import jointCompile.JavaPrinter
-
 class GroovyGreeter{
 
     private final String toGreet;

libs/groovylib/test/resources/hello-groovy/joint-compile/src/GroovyGreeter.groovy

@@ -1,8 +1,5 @@
 package jointcompile;
 
-import jointcompile.GroovyGreeter;
-
-
 public class JavaMain {
 
   public static void main(String[] args) {