Question

I’m trying to get a real equivalent for Java’s public static final in Scala for using TwiP.

Creating a val in an object doesn’t work for me, because it’s part of a new generated class Example$.class and TwiP can’t access it from class Example.class.

Here’s an example of a Java Class I’m trying to port to Scala:

public static final String[] MY_STRINGS = { "A", "B", "C" };

@Test
public void myTest(@Values("MY_STRINGS") String string) {
  ...
}

But I don’t know how to port the public static final to Scala. If it’s a val in an object like here

@RunWith(classOf[TwiP])
class Foo {

  import Foo.MY_STRINGS

  @Test
  def testTwiP(@Values("MY_STRINGS") value: String): Unit = {
    println("I'm testing value " + value + ".")
  }

}

object Foo {
  val MY_STRINGS = Array("A", "B", "C")
}

I only get the following exception:

net.sf.twip.internal.TwipConfigurationError:
there is no method or field 'MY_STRINGS' named in the @Values annotation of Parameter#1

How can I solve the problem using Scala?

Answer 1

The following Scala code:

class Foo{
  import Bar.MY_STRINGS
}
object Bar{
  val MY_STRINGS=Array("A","B","C")
}

Generates the following Java classes:

public final class Bar extends java.lang.Object{
    public static final java.lang.String[] MY_STRINGS();
    public static final int $tag()       throws java.rmi.RemoteException;
}
public final class Bar$ extends java.lang.Object implements scala.ScalaObject{
    public static final Bar$ MODULE$;
    public static {};
    public Bar$();
    public java.lang.String[] MY_STRINGS();
    public int $tag()       throws java.rmi.RemoteException;
}
public class Foo extends java.lang.Object implements scala.ScalaObject{
    public Foo();
    public int $tag()       throws java.rmi.RemoteException;
}

The following Scala code:

class Foo{
  import Foo.MY_STRINGS
}
object Foo{
  val MY_STRINGS=Array("A","B","C")
}

Generates the following Java classes:

public class Foo extends java.lang.Object implements scala.ScalaObject{
    public Foo();
    public int $tag()       throws java.rmi.RemoteException;
}
public final class Foo$ extends java.lang.Object implements scala.ScalaObject{
    public static final Foo$ MODULE$;
    public static {};
    public Foo$();
    public java.lang.String[] MY_STRINGS();
    public int $tag()       throws java.rmi.RemoteException;
}

The fact that static members aren’t defined on the class when the object has the same name as the class is Scala Bug #1735 and it’s fixed in Scala 2.8 snapshots.

So it looks like TwiP isn’t going to work at all unless you either upgrade Scala, or find a way to get TwiP to work with non-Static parameter generation methods.