diff -r 000000000000 -r ebedd84fba80 launcher/fx/src/test/java/org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoaderTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/launcher/fx/src/test/java/org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoaderTest.java	Mon Jun 10 18:12:38 2013 +0200
@@ -0,0 +1,106 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.bck2brwsr.launcher.fximpl;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.net.URL;
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+import static org.testng.Assert.*;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+/**
+ *
+ * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ */
+public class JsClassLoaderTest {
+    private static ClassLoader loader;
+    private static Class<?> methodClass;
+    
+    public JsClassLoaderTest() {
+    }
+
+    @BeforeClass
+    public static void setUpClass() throws Exception {
+        ScriptEngineManager sem = new ScriptEngineManager();
+        final ScriptEngine eng = sem.getEngineByMimeType("text/javascript");
+        
+        URL my = JsClassLoaderTest.class.getProtectionDomain().getCodeSource().getLocation();
+        ClassLoader parent = JsClassLoaderTest.class.getClassLoader().getParent();
+        loader = new JsClassLoader(new URL[] { my }, parent) {
+            @Override
+            protected JsClassLoader.Fn defineFn(String code, String... names) {
+                StringBuilder sb = new StringBuilder();
+                sb.append("(function() {");
+                sb.append("var r = {};");
+                sb.append("r.fn = function(");
+                String sep = "";
+                for (String n : names) {
+                    sb.append(sep);
+                    sb.append(n);
+                    sep = ", ";
+                }
+                sb.append(") {");
+                sb.append(code);
+                sb.append("};");
+                sb.append("return r;");
+                sb.append("})()");
+                try {
+                    final Object val = eng.eval(sb.toString());
+                    return new JsClassLoader.Fn() {
+                        @Override
+                        public Object invoke(Object... args) throws Exception {
+                            Invocable inv = (Invocable)eng;
+                            return inv.invokeMethod(val, "fn", args);
+                        }
+                    };
+                } catch (ScriptException ex) {
+                    throw new LinkageError("Can't parse: " + sb, ex);
+                }
+            }
+        };
+        
+        methodClass = loader.loadClass(JsMethods.class.getName());
+    }
+    
+    @Test public void noParamMethod() throws Throwable {
+        Method plus = methodClass.getMethod("fortyTwo");
+        try {
+            final Object val = plus.invoke(null);
+            assertTrue(val instanceof Number, "A number returned " + val);
+            assertEquals(((Number)val).intValue(), 42);
+        } catch (InvocationTargetException ex) {
+            throw ex.getTargetException();
+        }
+    }
+    /*
+    @Test public void testExecuteScript() throws Throwable {
+        Method plus = methodClass.getMethod("plus", int.class, int.class);
+        try {
+            assertEquals(plus.invoke(null, 10, 20), 30);
+        } catch (InvocationTargetException ex) {
+            throw ex.getTargetException();
+        }
+    }
+    */
+
+}
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