Hm. I spent an hour responding in detail to your example. When I return, the example has changed out of all recognition. That's a losing game. Who knows what will be here when I come back, if I start over.

Even with the turn around, you are still producing factorial( 0) == 0 when it should (by convention) be 1.

And then what is the point of testing 0 through 7? Are you expecting Perl to forget how to do math? Or recursion? Why not test 8 through 170?

You have no tests pertaining to 32/64-bit integer limits; or detecting when results start becoming inaccurate due to floating point round-off.

But those are test failures, not those of the test tools.

In vastly abbreviated summary. Nothing your test suit does cannot be done more simply and with less work, without the hierarchy of modules you use; or even with them but in the same file.

But many of the things I routinely do whilst testing cannot be done with those modules in place.

Ergo: those modules make work; get in the way; cut down my options and produce "results" I have no want for nor need of.

When everything runs correctly, I want silence. (Or at the very most "All tests past".) Anything else is just noise.

When something fails, I want to go straight to the source of the failure. I don't need to try and paraphrase the code of each test in three words of English, because once I'm at the line that failed, I can see what that line does.

So once again, *I* have no use for those modules. They require *me* to do (at least) twice as much work to achieve the same result. That is *my* (deeply considered) opinion.

I appreciate that your opinion is different. I'm not stopping you from using whatever cpu-sapping, productivity sapping methodologies and make-work working practices you feel you need to fit in.