Paul Jones has an update today onm his blog concerning the Solar Framework and some of the testing strategies surrounding it.
Inspired by Greg's PEAR_PHPTest class, I've developed a bare-bones Solar_Test_Assert class that tests assertions and throws PHP5 exceptions on assertion failures. Add to that a quick hack to run all tests at once recursively through subdirectories (courtesy of the "pear run-tests -r" switch), and you get a convenient all-at-once testing tool for Solar.
In the current release of .phpt test format, which is supported very well by Greg Beaver's "pear run-tests" code. The .phpt testing strategy compares the output of a test script to an expected output string, and passes if the outputs match.
He mentions also rewriting the previous Solar tests to match this new structure as well...