1. Why should we test? How should we test?
Testing with JUnit
Why should we test?
How should we test?
Arianne Meeting 2010
Markus Keunecke

2. Summary Introduction Testframework JUnit Using JUnit Coverage
Continuous Integration
JUnit and Stendhal
Conclusion
Arianne Meeting 2010
Markus Keunecke

3. Introduction With Testing you want to find errors
Earlier found errors are fixable with much less effort than later found error
Existing tests give confidence in making changes
Running tests after each change makes it possible to find errors in each change
Arianne Meeting 2010
Markus Keunecke

4. Introduction Automated tests ease unit testing
Develop tests parallel to „normal“ functions
Extreme: Test driven development
Good way of development
Make small changes
Run tests after each change
Commit after having „green bar“
Continuously update your local sandbox
Arianne Meeting 2010
Markus Keunecke

5. Testframework JUnit
A well known and widely used test framework for java
Open source licence
Current version is 4.8.1
Integration for Eclipse and Hudson available
Find more information at
Arianne Meeting 2010
Markus Keunecke

6. Using JUnit
Prerequisite: junit.jar must be in class path (or build path for eclipse project)
A test case is a class with several test methods
Test methods are annotated
Test cases can be arranged into test suites:
Empty class
@RunWith(Suite.class)
@SuiteClasses({MyTest.class, AnotherTest.class})
Arianne Meeting 2010
Markus Keunecke

7. Using JUnit Asserts for checking results in your test
Expected exceptions in a test
Setting up special requirements before a test
Cleaning up after a test
Tests can be run in several ways
Ant target for automatic builds in hudson or ant based IDEs like Netbeans
Eclipse
Arianne Meeting 2010
Markus Keunecke

8. Coverage Measurement to get an idea if you have sufficient tests
Measure which code was executed by tests
Several kinds of coverages measured by tools
Package, Class,Method and Block
But: Limited expressiveness as you can gain high coverage without asserting sth. in your tests
Arianne Meeting 2010
Markus Keunecke

9. Coverage Example tools: Emma and Cobertura
Emma has a good eclipse integration called EclEmma
Cobertura is used on our Continuous Integration server Hudson
Arianne Meeting 2010
Markus Keunecke

10. Arianne Meeting 2010
Markus Keunecke

11. Coverage
Arianne Meeting 2010
Markus Keunecke

12. Coverage
Arianne Meeting 2010
Markus Keunecke

13. Continuous Integration
Ease collaboration
Less time spent on finding bugs in interactions between different persons' works
Early integration reduces the number of possible changes that broke something
Arianne Meeting 2010
Markus Keunecke

14. Continuous Integration
„Check in often and update often“
Run all tests after each change
Use automated tests
ion.html
Arianne Meeting 2010
Markus Keunecke

15. JUnit and Stendhal Stendhal has some test supporting tools
ChatTestCreator
*TestHelper-classes located in test folder in the package utilities
Stendhal does CI with hudson
May have noticed hudson_bot in #arianne
tests run every day at about 5:30 am and measure coverage on the hudson
Count todos, findbugs analysis, compiler warnings
Arianne Meeting 2010
Markus Keunecke

16. Conclusion Learned several things Why test? How to test?
How to determine „enough“ testing?
How to get benefit from automated testing
How do we use JUnit in Stendhal?
But: Unit testing alone is not enough, there are still several other things to be tested by human beings!
Arianne Meeting 2010
Markus Keunecke