What are some Open Source Java projects with good, fine-grained unit test coverage?

Question

I'm working on a Java decompiler with correctness(*) as a primary design goal. To test it, I'm looking for some Java Open Source projects with fine-grained unit test coverage. These projects can be large or small, but test should exist which cover individual classes or methods. I plan to compile these projects with various compilers/settings, decompile them, recompile them, and run the projects' unit tests. Any suggestions would be appreciated. I'd like a combination of JDK1.5+ and JDK1.4 (or prior) codebases.

(*) correctness meaning that the decompiled class files can be recompiled into functionally equivalent object code.

In case anyone's wondering, my goal is to produce a tool to help IT shops support Java abandonware -- systems no longer supported but without source code available.

Answer 1

One good place for finding such projects might be http://www.testabilityexplorer.org/ - They have metrics for the testability of open source projects. I'm not 100% sure, but maybe they also record code coverage (or at least you can reason that projects with a good testability score probably have tests).

As for some specific project, FitNesse should have a good test suite. Also, here is my shameless plug - it has a good test suite. :)