diff -r 000000000000 -r a0505844750a vm/src/test/java/org/apidesign/vm4brwsr/NumberTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vm/src/test/java/org/apidesign/vm4brwsr/NumberTest.java	Tue Oct 16 18:04:11 2012 +0200
@@ -0,0 +1,82 @@
+/**
+ * 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 javax.script.Invocable;
+import javax.script.ScriptException;
+import org.testng.annotations.BeforeClass;
+import static org.testng.Assert.*;
+import org.testng.annotations.Test;
+
+/**
+ *
+ * @author Jaroslav Tulach <jtulach@netbeans.org>
+ */
+public class NumberTest {
+    @Test public void integerFromString() throws Exception {
+        assertExec("Can convert string to integer", "java_lang_Integer_parseIntILjava_lang_String",
+            Double.valueOf(333), "333"
+        );
+    }
+
+    @Test public void doubleFromString() throws Exception {
+        assertExec("Can convert string to double", "java_lang_Double_parseDoubleDLjava_lang_String",
+            Double.valueOf(33.3), "33.3"
+        );
+    }
+
+    @Test public void autoboxDouble() throws Exception {
+        assertExec("Autoboxing of doubles is OK", "org_apidesign_vm4brwsr_Numbers_autoboxDblToStringLjava_lang_String",
+            "3.3"
+        );
+    }
+
+    
+    private static CharSequence codeSeq;
+    private static Invocable code;
+
+    @BeforeClass
+    public void compileTheCode() throws Exception {
+        if (codeSeq == null) {
+            StringBuilder sb = new StringBuilder();
+            code = StaticMethodTest.compileClass(sb, "org/apidesign/vm4brwsr/Numbers");
+            codeSeq = sb;
+        }
+    }
+
+    private static void assertExec(
+        String msg, String methodName, Object expRes, Object... args) throws Exception {
+
+        Object ret = null;
+        try {
+            ret = code.invokeFunction(methodName, args);
+        } catch (ScriptException ex) {
+            fail("Execution failed in\n" + codeSeq, ex);
+        } catch (NoSuchMethodException ex) {
+            fail("Cannot find method in\n" + codeSeq, ex);
+        }
+        if (ret == null && expRes == null) {
+            return;
+        }
+        if (expRes.equals(ret)) {
+            return;
+        }
+        assertEquals(ret, expRes, msg + "was: " + ret + "\n" + codeSeq);
+    }
+    
+}