Then I create unit tests for the to-be-created implementations using some mock objects framework for all dependencies. These test the work interface contract as I drew it.
Do you use easymock or something else for this, cause it seems that it does not test interfaces. Only if you have a implementation in place can you use easymock to test the interface contract.
you don't really ever want to test an interface IMHO, since an interface doesn't do anything. You want to test that a certain component implements the interface correctly. Take another look at the sample in the "unit testing woes" thread, for a bigger example of the following technique:
public interface MyContract{ doBlah(); }
public class MyContractImpl{ public doBlah() {} }
public class MyContractImpl2{ public doBlah() {} }public abstract class AbstractMyContractTestCase extends TestCase
{
// ... /** concrete subclasses must provide an implementation of
MyContract. */
protected abstract MyContract getComponent();// ...
// tests go here }
public MyContractImplTestCase extends AbstractMyContractTestCase
{
protected MyContract getComponent()
{
return new MyContractImpl();
}// MyContract is tested by superclass... }
public MyContractImpl2TestCase extends AbstractMyContractTestCase
{
protected MyContract getComponent()
{
return new MyContractImpl2();
}// MyContract is tested by superclass... }
you can write the abstract test case first (though you can't run it), then create the concrete test cases just before you create your concrete implementations. You could test your tests like this:
// don't test your tests!
public MyContractTestCaseTestCase extends AbstractMyContractTestCase
{
protected MyContract getComponent()
{
MockControl.createControl(MyContract.class).getMock();
}// MyContract is tested by superclass...the test will fail as // the mock doesn't work of course! }
but there's not really any reason to once you get used to these kinds of techniques.
BTW, there's books full of tips like this. Java Extreme Programming Cookbook is a nice one; the JUnit chapter, and some other excerpts are available for free online:
http://www.oreilly.com/catalog/jextprockbk/chapter/ch04.pdf http://www.onjava.com/pub/a/onjava/excerpt/javaxpcookbook/index1.html http://www.onjava.com/pub/a/onjava/excerpt/javaxpcookbook/index2.html http://www.onjava.com/pub/a/onjava/excerpt/javaxpcookbook/index3.html
I'd round of with a joke involving paper and coffee, but can't think of any.
one is "brewing up" about coffee being in paper cups yet being afraid of the paper/coffee combo otherwise...and there must be something to say about me liking coffee so much while critizing beans [1]. But nothing really funny. I always envy funny people.
-- g'night!
- Leo Simons
----------------------------------------------------------------------- Weblog -- http://leosimons.com/ IoC Component Glue -- http://jicarilla.org/ Articles & Opinions -- http://articles.leosimons.com/ ----------------------------------------------------------------------- "We started off trying to set up a small anarchist community, but people wouldn't obey the rules." -- Alan Bennett
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
