I'm using a recent image.
According to the class docs,
TestRunner runTests
and
TestRunner runTests: '* test*'
should both work.
However, both result in walkbacks.
The first problem is that the Morph itself doesn't get opened, so you get a walkback because the Morph stuff hasn't been initialized.
This can be fixed in runTests and runTests: by making them call open, and making TestRunner class>>open return a TestRunner, not a SystemWindow.
Then runTests: is broken further because it calls some methods that don't exist (classPatternFrom: and selectorPatternFrom:).
In fact, there are several messages called in TestRunner that aren't implemented:
TestRunner>>openAsMorph calls TestRunner>>open TestRunner>>runTests: calls classPattern:, selectorPattern:, classPatternFrom: and selectorPatternFrom: TestRunner>>showResultDefects calls TestRunner>>result TestRunner>>showResultSummary calls TestRunner>>failureMessage