Add configuration option OnlyStaticConstants to RSpec/DescribedClass

[ydah]

Fix: #1741 (comment)
Fix: #1741 (comment)

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• Added tests.
• Updated documentation.
• Added an entry to the CHANGELOG.md if the new code introduces user-observable changes.
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[bquorning]

@pirj, I would love to hear your opinion on this PR.

[pirj]

I see it as a code smell when constants of the class under test are referenced from its spec, at least in a way that #1741 describes.

In general, this option probably makes sense to avoid offences in examples that are less coupled with the class under test.

I don’t have experience turning on Sorbet for specs, so I can’t suggest anything on this front.

I don’t take the “our CI pipelines fail” argument given that auto-correction doesn’t break the spec.

Personally, I don’t see why ‘described_class::MyException' is any different from ‘described_class::VERSION’, but I understand that some people may prefer to use different styles for them.

Again, personally I think ‘described_class’ was a mistake, and we it’s good to quote class names in the top-level example group’s description, and to use the full class name elsewhere in the spec, with no indirection.

[bquorning]

Again, personally I think ‘described_class’ was a mistake, and we it’s good to quote class names in the top-level example group’s description, and to use the full class name elsewhere in the spec, with no indirection.

I don’t remember us having this discussion before. I’m not sure I find described_class to be that useful either. Do you know why it’s even a feature in RSpec?

[pirj]

why it’s even a feature in RSpec?

This I can’t remember, but there’s a funny story about the RSpec 3 release and described_class, also a nice compilation of quotes and opinions in a discussion below the description rubocop/rspec-style-guide#104. Since most likely the described_class will stay in RSpec 4, the cop should remain in some form, too.

If it’s not a big maintenance overhead for us to provide our users with an optional … option to style their code the way they like, why not?