Presentation-layer testing - JUnit in Action - page 222

public void testSearch() {
// Same as before...
}

@Test
public void testSearchOnErrSaveScreen() throws Throwable {
try {
this .testSearch();
} catch (Throwable t) {
this .captureScreenshot(t);
}
}
We've added a new method called captureScreenshot b , which takes a Throwable
argument and calls the Selenium captureScreenshot method C . We refactored our
test method by creating a new method testSearchOnErrSaveScreen D , removing
@Test from testSearch , and adding it to the new method instead.
To avoid repeating this code pattern in every method that wants to capture a screen
shot on failure requires extending JU nit, which is beyond the scope of this section.
This concludes our Selenium survey; next, we contrast and compare HtmlUnit and
Selenium before presenting our chapter summary.

D

12.9 HtmlUnit versus Selenium

Here's a recap of the similarities and differences you'll find between HtmlUnit
and Selenium.
The similarities are that both are free and open source and both require Java 5 as
the minimum platform requirement.
The major difference between the two is that HtmlUnit emulates a specific web
browser, whereas Selenium drives a real web browser process. When using Sele-
nium, the browser itself provides support for JavaScript. In HtmlUnit 2.7, Mozilla's
Rhino 18 1.7 Release 2 engine provides JavaScript support, and specific browser
behavior is emulated.

Use HtmlUnit when
Use HtmlUnit when your application is independent of operating system features
and browser-specific implementations not accounted for by HtmlUnit, like Java-
Script, DOM, SCC, and so on.

Use Selenium when
Use Selenium when you require validation of specific browsers and operating sys-
tems, especially if the application takes advantage of or depends on a browser's
specific implementation of JavaScript, DOM, CSS, and the like.

18

Mozilla Rhino: http://www.mozilla.org/rhino/