diff -r 000000000000 -r a0f15cb8c730 chat/js/src/test/java/org/apidesign/demo/chat/js/JsInteractionTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/chat/js/src/test/java/org/apidesign/demo/chat/js/JsInteractionTest.java	Fri Apr 22 05:56:47 2016 +0200
@@ -0,0 +1,64 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.apidesign.demo.chat.js;
+
+import java.io.Closeable;
+import net.java.html.boot.script.Scripts;
+import org.netbeans.html.boot.spi.Fn;
+import static org.testng.Assert.assertEquals;
+import org.testng.annotations.AfterMethod;
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.Test;
+
+/** Tests for behavior of @JavaScriptBody methods. Set your JavaScript 
+ * environment up (for example define <code>alert</code> or use some
+ * emulation library like <em>env.js</em>), register script presenter 
+ * and then you can call methods that deal with JavaScript in your tests.
+ */
+public class JsInteractionTest {
+    private Closeable jsEngine;
+    @BeforeMethod public void initializeJSEngine() throws Exception {
+        jsEngine = Fn.activate(Scripts.createPresenter());
+    }
+    
+    @AfterMethod public void shutdownJSEngine() throws Exception {
+        jsEngine.close();
+    }
+    
+    @Test public void testCallbackFromJavaScript() throws Exception {
+        class R implements Runnable {
+            int called;
+
+            @Override
+            public void run() {
+                called++;
+            }
+        }
+        R callback = new R();
+        
+        Dialogs.confirm("Hello", callback);
+        
+        assertEquals(callback.called, 1, "One immediate callback");
+    }
+  }