why can't I instantiate a subclass of TestCase using JavaScript on Rhino

Question

I use Rhino to embed JavaScript in my Java code. In JavaScript it failed to instantiate a subclass of TestCase, which is a class from JUnit 3, but it does succeed to instantiate a subclass of Assert, which is the superclass of TestCase.
Below is some code to show this:

package com.example.test;

import junit.framework.Assert;
import junit.framework.TestCase;
import org.mozilla.javascript.*;

public class MyFirstJavaProgram {
    public static void main(String[] args) {
        try {
            Context cx = Context.enter();
            Scriptable scope = new ImporterTopLevel(cx);
            String js = new String();
            js += "importPackage(Packages.com.example.test);";
            js += "importClass(java.lang.System);";
            js += "var testCaseClass = new TestCaseClass();";
            js += "System.out.println(\"testCaseClass: \" + testCaseClass);";
            js += "var assertClass = new AssertClass();";
            js += "System.out.println(\"assertClass: \" + assertClass);";
            cx.evaluateString(scope, js, "<cmd>", 1, null);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}

class TestCaseClass extends TestCase { 
    public TestCaseClass() {} 
}
class AssertClass extends Assert { 
    public AssertClass() {} 
}

And the output was:

testCaseClass: null(com.example.test.TestCaseClass)
assertClass: com.example.test.AssertClass@17943a4

Please don't ask me why I am doing this, let's just say I have to.

Thank you for your patience.

Answer 1

The string you're seeing:

null(com.example.test.TestCaseClass)

is exactly new TestCase().toString() , the string representation of an unnamed test; this code is working.

Try:

class TestCaseClass extends TestCase { 
    public TestCaseClass() {
        super("Named Test");
    } 
}

to make this clearer.