Jester – The JUnit Test Tester “Why just think your tests are good when you can know for sure? Sometimes Jester tells me my tests are airtight, but sometimes the changes it finds come as a bolt out of the blue. Highly recommended.” Kent Beck

What is Jester? tests Java code and JUnit tests extends traditional Code Coverage finds test-suite problems finds untested statements provides unique insights into the structure of a code base

How does Jester work? (1) Knowing that a statement isn't executed at least once by the test suite, proves that it isn't being tested. If a line of code is executed, it doesn't necessarily follow that it's tested.

How does Jester work? (2) Unlike a traditional code coverage tool, Jester doesn't watch which lines of code have been executed. Instead Jester changes the source code, recompiles it, and runs the test suite to see if anything breaks. For instance, it will change a 1 to a 2, or change an if (x > y) to if (false). If the test suite isn't paying close enough attention to notice the change, then a test is missing.

How to install Jester download Jester from http://jester.sourceforge.net J2SE (>=1.4) and JUnit 3.8.1 must already be installed add Jester to the classpath run a simple example with 'test.bat‘ (the directory containing 'test.bat' must also be on the classpath.

How to run Jester (1)

How to run Jester (2)

Jester and XML

Jester‘s Licence Model Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, provided that the above copyright notice(s) and this permission notice appear in all copies of the Software and that both the above copyright notice(s) and this permission notice appear in supporting documentation.