Do you write scripts for a POSIX shell? There's a new test runner 'Brat', only a month old:
https://codeberg.org/sstephenson/brat
Brat='Brutal Runner for Automated Tests'. Intentionally small, to be embedded directly in projects, less than 1000 lines, TAP output.
If you've ever used Bats here's a comparison:
brat
brat - Brutal Runner for Automated Tests, a parallel TAP testing harness for the POSIX shell
Codeberg.org (codeberg.org)
(essentially it's more minimal, less dependencies, probably faster, much more portable)
I've been using it to test YSH (Oils project).