diff -r ae352b763959 -r d382dacfd73f rt/vm/src/test/java/org/apidesign/vm4brwsr/NumberTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/vm/src/test/java/org/apidesign/vm4brwsr/NumberTest.java	Tue Feb 26 16:54:16 2013 +0100
@@ -0,0 +1,169 @@
+/**
+ * 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 static org.testng.Assert.*;
+import org.testng.annotations.BeforeClass;
+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", Integer.class, "parseInt__ILjava_lang_String_2",
+            Double.valueOf(333), "333"
+        );
+    }
+
+    @Test public void doubleFromString() throws Exception {
+        assertExec("Can convert string to double", Double.class, "parseDouble__DLjava_lang_String_2",
+            Double.valueOf(33.3), "33.3"
+        );
+    }
+
+    @Test public void autoboxDouble() throws Exception {
+        assertExec("Autoboxing of doubles is OK", Numbers.class, "autoboxDblToString__Ljava_lang_String_2",
+            "3.3"
+        );
+    }
+    
+    @Test public void javalog1000() throws Exception {
+        assertEquals(3.0, Math.log10(1000.0), 0.00003, "log_10(1000) == 3");
+    }
+
+    @Test public void jslog1000() throws Exception {
+        assertExec("log_10(1000) == 3", Math.class, "log10__DD", 
+            Double.valueOf(3.0), 1000.0
+        );
+    }
+    
+    @Test public void javaRem() {
+        assertEquals(3, Numbers.rem(303, 10));
+    }
+    @Test public void jsRem() throws Exception {
+        assertExec("Should be three", Numbers.class, "rem__III", 
+            Double.valueOf(3.0), 303, 10
+        );
+    }
+    
+    @Test public void deserializeInt() throws Exception {
+        int exp = Numbers.deserInt();
+        assertExec("Should be the same", Numbers.class, "deserInt__I", 
+            Double.valueOf(exp)
+        );
+    }
+
+    @Test public void deserializeSimpleLong() throws Exception {
+        assertExec("Should be 3454", Numbers.class, "deserLong__J_3B", 
+            Double.valueOf(3454), 
+            new byte[] { (byte)0, (byte)0, (byte)0, (byte)0, (byte)0, (byte)0, (byte)13, (byte)126 }
+        );
+    }
+    /* XXX: JavaScript cannot represent as big longs as Java. 
+    @Test public void deserializeLargeLong() throws Exception {
+        final byte[] arr = new byte[] {
+            (byte)64, (byte)8, (byte)0, (byte)0, (byte)0, (byte)0, (byte)0, (byte)0
+        };
+        long exp = Numbers.deserLong(arr);
+        assertExec("Should be " + exp, "org_apidesign_vm4brwsr_Numbers_deserLong__JAB", 
+            Double.valueOf(exp), arr);
+    }
+    */
+    
+    @Test public void deserializeFloatInJava() throws Exception {
+        float f = 54324.32423f;
+        float r = Numbers.deserFloat();
+        assertEquals(r, f, "Floats are the same");
+    }
+    
+    @Test public void deserializeFloatInJS() throws Exception {
+        float f = 54324.32423f;
+        assertExec("Should be the same", Numbers.class, "deserFloat__F", 
+            Double.valueOf(f)
+        );
+    }
+
+    @Test public void deserializeDoubleInJava() throws Exception {
+        double f = 3.0;
+        double r = Numbers.deserDouble();
+        assertEquals(r, f, 0.001, "Doubles are the same");
+    }
+    
+    @Test public void deserializeDoubleInJS() throws Exception {
+        double f = 3.0;
+        assertExec("Should be the same", Numbers.class, "deserDouble__D", f);
+    }
+    /*
+    @Test public void serDouble() throws IOException {
+        double f = 3.0;
+        ByteArrayOutputStream os = new ByteArrayOutputStream();
+        DataOutputStream d = new DataOutputStream(os);
+        d.writeLong(3454);
+        d.close();
+        
+        StringBuilder sb = new StringBuilder();
+        byte[] arr = os.toByteArray();
+        for (int i = 0; i < arr.length; i++) {
+            sb.append("(byte)").append(arr[i]).append(", ");
+        }
+        fail("" + sb);
+    }
+*/    
+    @Test public void fiveInStringJS() throws Exception {
+        String s = Numbers.intToString();
+        assertExec("Should be the same: " + s, 
+            Numbers.class, "intToString__Ljava_lang_String_2", 
+            s
+        );
+    }
+
+    @Test public void sevenInStringJS() throws Exception {
+        String s = Numbers.floatToString();
+        assertExec("Should be the same: " + s, 
+            Numbers.class, "floatToString__Ljava_lang_String_2", 
+            s
+        );
+    }
+
+    private static TestVM code;
+
+    @BeforeClass
+    public void compileTheCode() throws Exception {
+        code = TestVM.compileClass("org/apidesign/vm4brwsr/Numbers");
+    }
+
+    private static void assertExec(
+        String msg, Class<?> clazz, String method, Object expRes, Object... args) throws Exception
+    {
+        Object ret = code.execCode(msg, clazz, method, expRes, args);
+        if (ret == null) {
+            return;
+        }
+        if (expRes instanceof Double && ret instanceof Double) {
+            double expD = ((Double)expRes).doubleValue();
+            double retD = ((Double)ret).doubleValue();
+            assertEquals(retD, expD, 0.000004, msg + " "
+                    + code.toString());
+            return;
+        }
+        assertEquals(ret, expRes, msg + " " + code.toString());
+    }
+    
+}