Introduce Unit Tests

[invarianz]

First off; thanks for this amazing port from OpenBSD.

For a long while I wanted to contribute something and understand vi's internals, however my C is a bit rusty (taught a college level course years ago and worked on some projects) so it was always pretty intimidating to get into this code base.

Currently, AI is helping me to get a grasp of what is going on here and I realized that tests on vi's behavior are missing.

Now, I forked the repo and played around with a coding assistant (Claude) and it generated a pretty nice initial test harness for this code repo that is purely written in POSIX sh.

I would like to open a PR but first I wanted to know: is this even something you would consider? I would surely test and proof-read the provided POSIX sh solution and integrate it with Github Actions, so a lot of the architectures listed in your README (everything except AIX, Solaris, illumos, Windows/Cygwin as they are not available as Github Action runners, not even as a VM) would be covered.

However, if you absolutely don't want any AI generated solutions or if you're not interested in a test harness I wont bother you with it!

Thanks again!

[johnsonjh]

Hi there,

I've considered adding some kind of tests to catch bugs and ensure that features work - likely more full integration testing of the full compiled binary, not unit tests of individual functions.

With that said, I'm not opposed to adding tests. The "issue" I see is that we aren't necessarily targeting conformance with POSIX sh, but aside from the features that OpenVi has added on top of OpenBSD vi, I would expect OpenVi to act exactly like OpenBSD vi (and also expect some deviation from POSIX vi).

If we do find fixes that can be done and are something that we want to integrate, making OpenVi more POSIX conforming, we should probably delay adding them here and instead send the patches upstream to OpenBSD (and also to @lichray for the nvi2 project).

While I'm still very skeptical of AI (even though I have used it somewhat successfully - not in this project). I won't say "no AI", but a) explicitly say that AI was used and b) ensure that you have fully reviewed any changes yourself first before sending them to me.

[lichray]

Sven initiated a test suite a while back: https://repo.or.cz/nvi.git/history/HEAD:/tests

sh or not, I think we aim to test the visible behaviors that users can interact with, where C mostly do not matter. Expanding that concept to vi (instead of ex), though, would require an innovative approach.