add determine-cask-runners command

[bevanjkay]

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes? Here's an example.
• Have you successfully run brew style with your changes locally?
• Have you successfully run brew typecheck with your changes locally?
• Have you successfully run brew tests with your changes locally?

---

This is a draft of moving the commands that generate the matrixes for our homebrew-cask CI to a DevCmd in Brew.

[MikeMcQuaid]

Looks good so far!

[samford]

Testing this locally using the CodeQL CLI, the errors relate to the repeating [^\s",] and trailing \s parts of [^\s",]+)"?,?\s* in the DEPENDS_ON_MACOS_ARRAY_MEMBER regex snippet. I'm not very knowledgeable about the issue that CodeQL is referencing but using possessive quantifiers (++ and *+ respectively) seems to be one way to resolve the errors.

However, I tested the regex changes locally and it works for something like depends_on macos: [":big_sur", ":sonoma"] but doesn't match something like depends_on macos: [:big_sur, :sonoma]. We only use a string for something like >= :big_sur, so that's a problem.

Making the repeating parts non-greedy ([^\\s",]+?, \s*?) doesn't trigger the CodeQL errors but I don't know if that addresses the underlying issue or just sidesteps the errors. After tinkering with this some more, I ended up simplifying the case condition regex and expanding the array member regex to also handle strings with a comparator (it currently only handles symbols and strings with symbol text like ":big_sur"). [MacosRequirement can only handle an array of symbols currently but there may be something to be said for handling something like [">= :big_sur", "<= :sequoia"], as that's less verbose than explicitly specifying every macOS version in that range.]

I've created a PR in homebrew/cask first as a smoke test (Homebrew/homebrew-cask#189969) and, if nothing explodes, I'll push the changes here as well.

[bevanjkay]

The tests aren't exhaustive, I'm not exactly how much coverage we are looking for here, as any major concerns will be revealed in CI which we can't quite replicate in the test suite.

[reitermarkus]

Doesn't need to be in this PR, but this should probably have some unit tests.

[MikeMcQuaid]

Thanks @bevanjkay!