Tutorials : StrutsTestCase: The Tool for Struts Unit testing :

Testing error situations

The failures we've encountered should remind us that every test program must also test the error situations. Luckily STC can handle this situation as well. I mentioned that the detail action needs an index value to function, and if we omit it we'll get an error as seen above:

. . . F Time: 1,6 There was 1 failure: 1) testActions(hansen.playground.TestStrutsAction) junit.framework.AssertionFailedError: was expecting '/detail.jsp' but received '/error.jsp'

Since the DetailDVDAction class forwards to error in two situations, we'll have to check which value was given to the Struts ActionError method. The test for a missing index sends the value "error.noindex": 

. . .
// Test the detail action - without an index
    setRequestPathInfo("/detail");
    actionPerform();
    verifyActionErrors(new String[] {"error.noindex"});

When we run the test program once more we receive no error messages.

If you continue your program with a new test in the same test-method then you should realize that the request object now contains a non-null ActionErrors object. If you don't clear it the next test using verifyNoActionErrors() will fail. To clear it, insert this statement in your code:

getRequest().setAttribute(Globals.ERROR_KEY,null);

See the complete test program here .

Conclusion

An important part of unit testing a Struts application is to test if the execute method of the Action classes work properly. STC sets up a simulated Struts environment that makes it very simple to code these tests. Since STC uses JUnit your test programs will fit nicely into the collections of unit tests you probably already have made for your application.

I've shown you how to code and run STC programs, and you've also seen that there may be some pieces missing in the simulated environment. A way to get an idea of what will work and what might not work is to browse through the STC JavaDoc. If you, for example, spend some time looking at the JavaDoc for the MockStrutsTestCase, you'll also see that there are features which we haven't covered yet.

In the next article we'll see how easy it is to replace the mock object environment with the Cactus framework, thereby using the real servlet environment set up by the web server. We'll also see how to handle the "setup once for all method calls" situation in an elegant way, and there'll be some other goodies to.

Continue on to Part 2

Resources

• A zip file with all the examples from this article and a war file ready to deploy on your web server.
• Introduction to StrutsTestCase at SourceForge 
• Information about the StrutsTestCase project
• StrutsTestCase discussion forum 
• The home page of Jakarta Struts
• Previous articles from JavaBoutique about Struts:
  - "Stepping through Jakarta Struts"
  - "Coding your second Jakarta Struts Application"
  - "Introducing: the Struts bean and logic Tag Libraries"
• A tutorial on JUnit

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