Fix compilation errors in Tests.scala

Author: ERSUCC

.bsp/sbt.json

@@ -0,0 +1 @@
+{"name":"sbt","version":"1.7.2","bspVersion":"2.0.0-M5","languages":["scala"],"argv":["/Library/Java/JavaVirtualMachines/jdk-17.0.2.jdk/Contents/Home/bin/java","-Xms100m","-Xmx100m","-classpath","/opt/homebrew/Cellar/sbt/1.10.11/libexec/bin/sbt-launch.jar","-Dsbt.script=/opt/homebrew/Cellar/sbt/1.10.11/libexec/bin/sbt","xsbt.boot.Boot","-bsp"]}

src/test/Tests.scala

@@ -15,9 +15,9 @@ object Tests {
 class Tests extends TestLanguage(Tests.testFiles) with BeforeAndAfterAll {
   System.setProperty("org.nlogo.preferHeadless", "true")
 
-  override def afterAll() {
+  override def afterAll(): Unit = {
     val file = new File("tmp/array")
-    def deleteRec(f: File) {
+    def deleteRec(f: File): Unit = {
       if (f.isDirectory) {
         f.listFiles().foreach(deleteRec)
       }