[lmm]

Well no, a lot of bugs didn't pass a type checker because a lot of languages don't have them. And some projects don't have unit tests.

[GFK_of_xmaspast]

> And some projects don't have unit tests.

If a bug did not cause a unit test to fail, then it passed the unit test suite. (Less cryptically, an empty set is still a set)

[recursive]

If we're getting that pedantic, the quote was "they passed unit tests". If the bug passed a 0-size set of unit tests, then it didn't actually pass any unit tests.

[eru]

They didn't pass any, but they passed all.

In any case, Rich Hickey probably had more context for his words.

[ank_the_elder]

We should take this discussion and publish it in the world-famous (and extremely popular) "Journal of the empty set." You will find most of my work published there, too. http://pic.blog.plover.com/math/major-screwups-4/emptyset.pn...

[zachrose]

Still though, 0% test coverage.

[eru]

Division by zero..

[lmm]

How so?

10 (say) lines of code, 0 lines covered by tests, test coverage is 0/10. No division by zero, nothing undefined happening.