Add test to validate test resources directory

src/test/java/org/gradle/playframework/plugins/PluginResourceDirectoryTests.java

@@ -0,0 +1,55 @@
+package org.gradle.playframework.plugins;
+
+import org.gradle.api.Project;
+import org.gradle.api.file.SourceDirectorySet;
+import org.gradle.api.tasks.SourceSet;
+import org.gradle.playframework.plugins.internal.PlayPluginHelper;
+import org.gradle.testfixtures.ProjectBuilder;
+import org.junit.Test;
+
+import java.io.File;
+import java.util.Collections;
+
+import static org.junit.Assert.assertEquals;
+
+public class PluginResourceDirectoryTests {
+    @Test
+    public void testResourcesDirectories() {
+        // given
+        Project project = ProjectBuilder
+                .builder()
+                .build();
+
+        // when
+        project.getPluginManager().apply(PlayPlugin.class);
+
+        SourceSet mainSourceSet = PlayPluginHelper.getMainJavaSourceSet(project);
+        SourceDirectorySet mainResourcesDirectorySet = mainSourceSet.getResources();
+
+        // then
+        assertEquals(
+                Collections.singleton(new File(project.getProjectDir(), "conf")),
+                mainResourcesDirectorySet.getSrcDirs()
+        );
+    }
+
+    @Test
+    public void testTestResourcesDirectories() {
+        // given
+        Project project = ProjectBuilder
+                .builder()
+                .build();
+
+        // when
+        project.getPluginManager().apply(PlayPlugin.class);
+
+        SourceSet testSourceSet = PlayPluginHelper.getTestJavaSourceSet(project);
+        SourceDirectorySet testResourcesDirectorySet = testSourceSet.getResources();
+
+        // then
+        assertEquals(
+                Collections.singleton(new File(project.getProjectDir(), "test/resources")),
+                testResourcesDirectorySet.getSrcDirs()
+        );
+    }
+}