The library currently doesn't employ any kind of fuzzing. I rely on multiple tests for every kind of input. I've found that is a pretty reliable way to test for "unknown unknowns", even if it's extremely time-consuming.
Adding testcase fuzzing is definitely something to consider though, because it would most likely have found the very issues this release fixes.
I recommend trying fuzz testing, it can be very effective (see my experiences here: http://forwardscattering.org/post/21)
Utf8-rewind looks like a nice library, I have looked into it before when researching unicode support. If I need to do more complex Unicode stuff in my language I will probably use it.
The library currently doesn't employ any kind of fuzzing. I rely on multiple tests for every kind of input. I've found that is a pretty reliable way to test for "unknown unknowns", even if it's extremely time-consuming.
Adding testcase fuzzing is definitely something to consider though, because it would most likely have found the very issues this release fixes.