Mutterings

At Webify, we have three main subsystems of our applications: Hibernate for the database layer, Spring for the component container layer and Tapestry for the Web UI layer.

It’s relatively easy to unit test Hibernate and Spring code via JUnit, they both provide hooks so you can start them up by hand. Tapestry, on the other hand, is meant to run within an application server - it requires a container to run. Well, mock objects have recently become popular as a way of testing code which requires a container to run; you just create the container objects which are used by this code so that it thinks it is running within a container:

        MockServletContext servCtx = new MockServletContext("/webroot");
        MockServletConfig servCfg = new MockServletConfig(servCtx, "tapestry");
        ApplicationServlet servlet = new ApplicationServlet();
        servlet.init(servCfg);

        MockHttpServletRequest req = new MockHttpServletRequest(servCtx, "GET", "/");
        MockHttpServletResponse resp = new MockHttpServletResponse();
        servlet.service(req, resp);
        if (!pageRequested) {
            fail("Home page was not executed");
        }

The ApplicationServlet is the method of entry into the Tapestry system. On the filesystem, you create a “tapestry.application” file in webroot/WEB-INF which contains the page definitions. In this case, this just tests that the Home page is rendered.

public class HomePage extends BasePage implements PageRenderListener {
    public void pageBeginRender(PageEvent arg0) {
        RequestTest.setPageRequested();
    }
}

Pretty simple, huh? Now we can do basic login testing as part of our unit tests to ensure that the Web UI actually works, rather than needing to run a container and testing it by hand!