The [2] link is uutils using the test suite that the GNU coreutils maintainers, including myself, created and continue to improve. This test suite has long predated uutils and gets equal, if not more, man-hours than the program implementations themselves.
When you say that no one bothered to do this testing until uutils existed, it feels like you are discrediting our work. Any other implementation is free to use our test suite, as long as they respect its licensing. Doing so is relatively straightforward; you just need to point a shell variable to the place with the just-built binaries.
Note that the man pages are a quick reference explaining the options. A lot of gotchas and further explanations are located in the texinfo manual, which is over 300 pages in PDF form [1]. If you notice areas where it could be improved, I would be happy to review your bug report sent to [email protected].
When you say that no one bothered to do this testing until uutils existed, it feels like you are discrediting our work. Any other implementation is free to use our test suite, as long as they respect its licensing. Doing so is relatively straightforward; you just need to point a shell variable to the place with the just-built binaries.
Note that the man pages are a quick reference explaining the options. A lot of gotchas and further explanations are located in the texinfo manual, which is over 300 pages in PDF form [1]. If you notice areas where it could be improved, I would be happy to review your bug report sent to [email protected].
[1] https://www.gnu.org/software/coreutils/manual/coreutils.html