@Test public void testExecValidate() throws Exception { BEANS.get(IExtensionRegistry.class).register(NameFieldExtension.class, NameField.class); MyForm myForm = new MyForm(); myForm.start(); NameField nameField = myForm.getNameField(); nameField.getUIFacade().parseAndSetValueFromUI("hans"); Assert.assertNull(nameField.getErrorStatus()); nameField.getUIFacade().parseAndSetValueFromUI("bernd"); Assert.assertNotNull(nameField.getErrorStatus()); nameField.getUIFacade().parseAndSetValueFromUI("berndExtension"); Assert.assertNotNull(nameField.getErrorStatus()); }