TDD (Test Driven Development) for Externals

I would like to use TDD for developing Externals.

It always seems to come down to issues with getting a mock RequestContext or PropertyContext object.

Is there a way to initialize a RequestContext object?

Is there a way to retrieve or instantiate a Request Context?

Implementing my own Mock object is daunting as for the sheer number of methods that need to be implemented.

External Method Signature
public Document myExternalMethod(RequestContext context) {}

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Comments

Rick Poulin

Haven't done it myself, but our team has had some success in the past using a combination of SpringMock and extending com.interwoven.livesite.runtime.impl.RuntimeRequestContext to provide a "TestRuntimeContext". Wasn't the fanciest of solutions, but it worked.

andydoerr_work

Thanks for the reference, I am looking into it now.

It would be great if I could see the initialization of the TestRequestContext.

Thanks again for your response!

- Andy

Bowker

Andy - If you get something working, I'm probably not the only one who would appreciate an example piece of code.

Rick Poulin

Before reading the following, let me point out that the whole purpose of our solution was to test things outside the confines of RequestContext alone, as I believe you are trying to do when you say "too many methods to implement when using a mock". If all you need is to stub getPageName() and the like, stick with EasyMock. What we needed to do is test things with the HttpServletRequest, Spring ApplicationContext, and Hibernate, which is why we needed this beastly setup.

So, in a nutshell...

Create a BaseTransactionalSpringTestCase which extends AbstractTransactionalDataSourceSpringContextTests and use that to set up your Spring stuff. This serves as the base class for any externals and controllers.

Write a shell class extending (or Mocking) LiveSite's UserSession, or just provide 'null' in the constructor below if you never use it.

Then, white a shell class (call it TestRequestContext) extending RuntimeRequestContext. Your constructor can look something like the following, and you now have access to create all three of those params from any test class extending BaseTransactionalSpringTestCase.


public TestRequestContext(ApplicationContext context, UserSession session, Locale locale);

Yes, it sucks to have to implement all those methods of the RequestContext, but now you only need to do it once and you have a shell RequestContext class that has access to mock the inner HttpServlet objects, as well as doing fun stuff with the Spring ApplicationContext. It's up to you to write your TestRequestContext to do something smart within the test context, for all those methods you intend to call. An IDE such as Eclipse will easily stub all the other methods you don't care about with "return null;" and whatnot.

Naturally, now you almost need a test for your TestRequestContext, so again, this is a trade-off between the depth of your tests and the complexity of your tests. This setup allowed us to test much more than by simply mocking the RequestContext, so in our specific case, it made sense.

Rick Poulin

To further qualify that, it now occurs to me that maybe your definition of 'mock' is different from mine. A "mock" is usually a shell object with some expected behaviour that only exists for the scope of the test -- usually supported by a mocking framework. I only now picked up on the fact that you said "Implementing my own Mock object is daunting", which to me is a testing stub -- writing a test class that implements the interface you want to mock, providing "real" behaviour suitable for testing.

Semantics aside, maybe you're not aware of frameworks like EasyMock. So, to qualify my previous statement "If all you need is to stub getPageName() and the like", consider this:


private MyExternal testSubject;

@Before
public void setup() {
    testSubject = new MyExternal();
}

@Test
public void myTestWithEasyMock() {
    RequestContext mockContext = EasyMock.createMock(RequestContext.class);
    EasyMock.expect(mockContext.getPageName()).andReturn("myPage");
    EasyMock.replay(mockContext);
    testSubject.myExternalMethod(context);
    // validate something
}

The "andReturn()" call can return other mocked objects, or you can call andThrows(new Exception()), or there's a whole wack of other neat things you can do.