Introduce/enable a rule for trailing commas in rubocop

[denrase]

We should discuss if we wanna use trailing commas and enable the rule we land on in rubocop.

I'm more in the no trailing commas camp, but I think we should discuss this before starting a PR.

Some quick google searches yielded:
rubocop/ruby-style-guide#273
https://rubystyle.guide/#no-trailing-parameters-comma
https://rubystyle.guide/#no-trailing-params-comma

[philipphofmann]

Sure that sounds reasonable. Are you up for a PR @denrase?

[denrase]

Sure! Do you or anyone from your team have an opinion on this?

[philipphofmann]

I'm not an expert on Ruby. Maybe it's worth checking out what we do here https://github.com/getsentry/sentry-ruby ?

[denrase]

@philipphofmann When trying to configure this, i wondered why rubocop is not issuing warnings when i made changes. Turns out, it is only configured for the Fastfile, as the AllCops include is overriding the default.

AllCops:
  Include:
    - '**/fastlane/Fastfile'

When removing the include, we get 232 offences, which may also include directories we don't care about.

Now the question is, is it supposed to be only configured for the Fastfile?

[github-actions]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Status: Backlog or Status: In Progress, I will leave it alone ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀

[philipphofmann]

This was fixed with #121