Livecheck: Skip archived stable URLs in formulae

[samford]

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This PR modifies livecheck to automatically skip formulae that have a stable URL from the Google Code Archive or Internet Archive, as these won't receive updates. I checked the PR history for related formulae and didn't see any that were updated while they were in this state, so I think it's safe to skip these formulae by default.

I initially considered restricting these automatic skips to formulae with a related stable archive URL but no head URL, as it may be possible to check for a new version in an upstream repository. However, I looked through formulae with this criteria and the upstream repositories weren't useful (i.e., they simply contained older versions than what Google Code Archive provides).

That said, it's possible to override these automatic skips with a livecheck block (if there's another source to check), so this should be fine. However, if there was another source to check, we should just update the stable URL to use that instead (so these skips wouldn't apply in that case).

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Some time ago, I created a related PR to remove Google Code Archive livecheck blocks from formulae: Homebrew/homebrew-core#64606

I'm planning to create a follow-up PR in homebrew-core to remove the livecheck blocks that skip some of these formulae, as they'll no longer be necessary.

[BrewTestBot]

Review period will end on 2021-01-05 at 00:00:00 UTC.

[BrewTestBot]

Review period ended.

[MikeMcQuaid]

Looks good but might be worth splitting into separate function/functions in livecheck.rb

[samford]

might be worth splitting into separate function/functions in livecheck.rb

The #skip_conditions method was originally a way of separating this [growing] logic from what's currently the #run_checks method. Is there value in decomposing #skip_conditions further?

If so, could you explain a bit more about what form you would prefer this to take (e.g., a separate method only for the "skipped" part of #skip_conditions or separate methods for each of the if blocks in #skip_conditions)?

[MikeMcQuaid]

The #skip_conditions method was originally a way of separating this [growing] logic from what's currently the #run_checks method. Is there value in decomposing #skip_conditions further?

Yes, I think probably.

or separate methods for each of the if blocks in #skip_conditions)?

This, ideally, unless you see no chance this list will ever be added to.

[samford]

The latest commit incorporates the following changes:

• Refactor Livecheck#skip_conditions into a Homebrew::Livecheck::SkipConditions module.
• Split the if blocks in #skip_conditions into separate module methods.
• Modify #skip_conditions and the related condition methods to always return the hash from Livecheck#status_hash (or nil), instead of printing any output.
• Rename #skip_conditions to #skip_information to better reflect that it only returns information (a hash) now, rather than printing anything.
• Create a #print_skip_information method that prints the livecheck output for the various skip conditions when provided with the hash output from #skip_information. This allows us to keep the printing logic in SkipConditions, so the related code in Livecheck#run_checks is simple/minimal.
• Move related tests from livecheck/livecheck_spec.rb to skip_conditions_spec.rb.
• Rework the SkipConditions tests to account for the related changes (and refactor a bit for better organization).

@MikeMcQuaid I may take another pass at this later but I don't think there will be substantial changes (if any). Feel free to review whenever you have time.

[MikeMcQuaid]

Nice work so far! Made a bunch of comments that apply elsewhere, have avoided repeating myself too much but assume I mean the same thing everywhere with e.g. nilable and unless

[MikeMcQuaid]

This type checking feels non-idiomatic , particularly considering it's a no-op if the type doesn't match.

[MikeMcQuaid]

This type check also feels like a smell given it's a no-op when it's not matched

[MikeMcQuaid]

Thanks again @samford!