I have a Bats test suite that's inherently disk and network I/O intensive. To cut down on the running times, I have split them into two with tags, so that they can be run in parallel on two CI nodes.

My setup_suite function does a lot of network I/O to avoid repeating them for each test again and again. Depending on which subset of the test suite is being run by --filter-tags <comma-separated-tag-list>, I can avoid doing some work in setup_suite.

If my setup function(s) knew which subset is being run, then I could do the above optimization.

One alternative to having Bats expose this information is to assign the <comma-separated-tag-list> to an environment variable and read it. It's not a terrible alternative, so I am happy to do it. I just thought that I'd throw out this idea and see what everybody else made of it.