diff -r 59d5596a9c6c -r d382dacfd73f rt/vm/src/test/java/org/apidesign/vm4brwsr/InstanceTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/vm/src/test/java/org/apidesign/vm4brwsr/InstanceTest.java	Tue Feb 26 16:54:16 2013 +0100
@@ -0,0 +1,166 @@
+/**
+ * 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.vm4brwsr;
+
+import org.testng.annotations.Test;
+import org.testng.annotations.BeforeClass;
+
+/**
+ *
+ * @author Jaroslav Tulach <jtulach@netbeans.org>
+ */
+public class InstanceTest {
+    @Test public void verifyDefaultDoubleValue() throws Exception {
+        assertExec(
+            "Will be zero",
+            Instance.class, "defaultDblValue__D",
+            Double.valueOf(0)
+        );
+    }
+    @Test public void verifyStaticMethodCall() throws Exception {
+        assertExec(
+            "Will be zero",
+            InstanceSub.class, "recallDbl__D",
+            Double.valueOf(0)
+        );
+    }
+    @Test public void verifyAssignedByteValue() throws Exception {
+        assertExec(
+            "Will one thirty one",
+            Instance.class, "assignedByteValue__B",
+            Double.valueOf(31)
+        );
+    }
+    @Test public void verifyMagicOne() throws Exception {
+        assertExec(
+            "Should be three and something",
+            Instance.class, "magicOne__D",
+            Double.valueOf(3.3)
+        );
+    }
+    @Test public void verifyInstanceMethods() throws Exception {
+        assertExec(
+            "Should be eleven as we invoke overwritten method, plus 44",
+            Instance.class, "virtualBytes__I",
+            Double.valueOf(55)
+        );
+    }
+    @Test public void verifyInterfaceMethods() throws Exception {
+        assertExec(
+            "Retruns default value",
+            Instance.class, "interfaceBytes__F",
+            Double.valueOf(31)
+        );
+    }
+
+    @Test public void isNull() throws Exception {
+        assertExec(
+            "Yes, we are instance",
+            Instance.class, "isNull__Z",
+            Double.valueOf(0.0)
+        );
+    }
+
+    @Test public void isInstanceOf() throws Exception {
+        assertExec(
+            "Yes, we are instance",
+            Instance.class, "instanceOf__ZI",
+            Double.valueOf(1.0), 2
+        );
+    }
+
+    @Test public void notInstanceOf() throws Exception {
+        assertExec(
+            "No, we are not an instance",
+            Instance.class, "instanceOf__ZI",
+            Double.valueOf(0.0), 1
+        );
+    }
+    @Test public void nullInstanceOf() throws Exception {
+        assertExec(
+            "No, null is not an instance",
+            Instance.class, "instanceOf__ZI",
+            Double.valueOf(0.0), 0
+        );
+    }
+    
+    @Test public void verifyCastToClass() throws Exception {
+        assertExec(
+            "Five signals all is good",
+            Instance.class, "castsWork__IZ",
+            Double.valueOf(5.0), false
+        );
+    }
+    @Test public void verifyCastToInterface() throws Exception {
+        assertExec(
+            "Five signals all is good",
+            Instance.class, "castsWork__IZ",
+            Double.valueOf(5.0), true
+        );
+    }
+    
+    @Test public void sharedConstructor() throws Exception {
+        assertExec(
+            "Constructor of first and 2nd instance should be the same",
+            Instance.class, "sharedConstructor__Z",
+            Double.valueOf(1.0)
+        );
+    }
+
+    @Test public void differentConstructor() throws Exception {
+        assertExec(
+            "Constructor of X and Y should be the different",
+            Instance.class, "differentConstructor__Z",
+            Double.valueOf(0)
+        );
+    }
+
+    @Test public void jsObjectIsLikeJavaObject() throws Exception {
+        assertExec(
+            "JavaScript object is instance of Java Object",
+            Instance.class, "iofObject__Z",
+            Double.valueOf(1)
+        );
+    }
+
+    @Test public void jsCallingConvention() throws Exception {
+        assertExec(
+            "Pointer to 'this' is passed automatically (and not as a first argument)",
+            Instance.class, "jscall__I",
+            Double.valueOf(31)
+        );
+    }
+    
+    protected String startCompilationWith() {
+        return "org/apidesign/vm4brwsr/Instance";
+    }
+    
+    private static TestVM code;
+    
+    @BeforeClass
+    public void compileTheCode() throws Exception {
+        code = TestVM.compileClass(startCompilationWith());
+    }
+    
+    private void assertExec(
+        String msg, Class clazz, String method, Object expRes, Object... args
+    ) throws Exception {
+        code.assertExec(msg, clazz, method, expRes, args);
+    }
+    
+}