Functional Testing

For a functional test, exercised through the user interface, it is likely you would want to use one of the tools designed for just that purpose. Currently these would most likely be one of:

• Vaadin TestBench
• Selenide
• Selenium

Vaadin TestBench is obviously Vaadin aware, but has a licence cost. Selenide is free and open source. Both use Selenium underneath to remove some of the issues of testing in an AJAX environment.

Component Ids

All the above tools provide various methods of detecting an element within a web page. The most robust is to use a CSS Selector, which in Vaadin’s case is provided by a Component.id

To assist testing, Krail automatically assigns a hierarchical id to selected components. This is done by an implementation of ComponentIdGenerator

This id is in the form of MyView-component-nestedcomponent-nestedcomponent to whatever depth is defined by your views and components. By default, anything which implements Layout is ignored, as these do not usually declare any components, and are not usually required for functional testing.

You can, however, use @AssignComponentId annotation to change this

Affect on Performance

Using CSS selectors makes robust testing through the UI a lot easier, but does have the penalty of incurring additional network traffic for all the extra labels, which you might not want in a production environment - though if performance is not an issue, they could also be used for application monitoring.

There is an outstanding issue to make it possible to switch this feature off via configuration.

Page Loading

One of the problems with automated testing is knowing when a page is ready to be tested. A PageLoading message is despatched on the MessageBus as the transition from one page to another is started, followed by a Page Ready message once the page has been built and data has been loaded.

In SimpleUI, the PageLoadingMessage sets the NavigationBar title to “Loading …”. When the PageReadyMessage is received, the title is set to the name of the View. This can be used by functional test code to determine whether the page is ready for testing.

Functional Test Support

VaadinTestBench has been replaced by Selenide for Functional Testing. This solution is not as complete as TestBench, but covers many use cases.

Component ids are now generated automatically to support functional testing.

A FunctionalTestSupport object provides a model of route to View / UI, and the components they contain.

To complement this, there is some early but useful work held currently in the test-app project which generates Page Objects for functional testing. These, along with some framework code, enable testing using Selenide, and could be extended easily for use with Vaadin TestBench - the objective it to enable the use of different test tools without changing the tests

See GeneratorPageObjects and the other classes in uk.q3c.krail.functest, in the test-app project

The code behind this will eventually become a separate library.