Do not try to expand nil Include when inheriting.

[juanxo]

When inheriting from a parent config file that has nullified an Include in any rule, it will currently fail as it will assume that the Include will always be an non-nullable array

Example:

# rubocop.yml
Style/StringLiterals:
  Include:
    - dir/**/*.rb

# child_dir/.rubocop.yml
inherit_from: ../.rubocop.yml
Style/StringLiterals:
  Include: ~

I'm currently using this pattern to remove a default Include pattern so it resorts back to the AllCops inclusion list, so setting it to [] does not accomplish the same effect.

---

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• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Ran bundle exec rake default. It executes all tests and runs RuboCop on its own code.
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[juanxo]

Not so sure about this test. I wanted to mostly check that going from not nil to nil and vice versa worked

[bbatsov]

I'm currently using this pattern to remove a default Include pattern so it resorts back to the AllCops inclusion list, so setting it to [] does not accomplish the same effect.

I'm OK with your proposal, but this is also something we should document in the configuration section of RuboCop, as generally I don't think we've considered the use of nil much there. //cc @koic @jonas054

[koic]

Yeah, I agree with @bbatsov.

[bbatsov]

@juanxo Ping :-)

[jonas054]

Looks good!

[bbatsov]

@juanxo Ping again :-)

[bbatsov]

@juanxo Ping again :-)

[koic]

@juanxo Ping.

[juanxo]

Hey, sorry for the long delay in answering. Will look to rebase and ship this