test file detection fragile

[gregvanl]

Testing #17039

The provided test file patterns don't work very well.

For example:

*test.py - will detect utest.py but not unittest.py

test.py - will detect utest.py but not unittest.py

[karthiknadig]

This is expected in python. when you name a file unittest.py it overrides the underlying library unittest. The files in your current working directory take precedence over the standard library.