andthennothing.net: Aspects“first there was a three-legged monkey...”tag:andthennothing.net,2005:TypoTypo2005-12-18T03:19:07+00:00Jonas Bengtssonjonas.b@home.seurn:uuid:8a929ecb-b508-485c-808a-a58a04fd7d752002-10-02T12:48:38+00:002005-12-18T03:19:07+00:00Aspects<p>I have looked at <a href="http://aosd.net/">Aspect-Oriented Programming</a> (and <a href="http://www.aspectj.org/">AspectJ</a>) before, and I’ve thought that it seems quite interesting, but also quite complicated. However, today I’ve read about one situation it seems to be really useful.<br /><br />In an article at <a href="http://www.xprogramming.com/">XProgramming.com</a> called <a href="http://www.xprogramming.com/xpmag/virtualMockObjects.htm">Virtual Mock Objects using AspectJ with <span class="caps">JUNIT</span></a>, Simon Monk and Stephen Hall is describing how AspectJ can be used to create virtual <a href="http://www.mockobjects.com/">mock objects</a>. With their “framework” (source code available <a href="http://www.shopwriter.co.uk/simon/aspectj/">here</a>) you just have your test case class subclass their <a href="http://www.shopwriter.co.uk/simon/aspectj/ComponentTestCase.java">ComponentTestCase</a> instead of <a href="http://www.junit.org/">JUnit</a>’s TestCase. You can then create virtual mock objects by calling setMock(className, methodName, mockResult) (or a couple of alternatives). It’s that simple! You can then use assertCalled() and assertArgumentPassed() to make sure the virtual mock objects are used in a correct manner. (There are more features in there. Check out the article for more details, it’s a good read!)<br /><br />I guess I have to look further into Aspect-Based Programming at some point. Perhaps when the AspectJ plug-in to <a href="http://www.eclipse.org/">Eclipse</a>, called <a href="http://www.eclipse.org/ajdt/"><span class="caps">AJDT</span></a>, is finished (it might be finished already, I’m not sure).</p>