[Fix #9580] Add New Cop to Enforce Bundler Gem filename

[gregfletch]

Add a new cop which enforces which bundler gem filename to use. By default, enforces Gemfile and its related Gemfile.lock file. Alternatively, setting RequiresGemfile to false enforces gems.rb and its related gems.locked file.

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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).
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• Squashed related commits together.
• Added tests.
• Ran bundle exec rake default. It executes all tests and runs RuboCop on its own code.
• Added an entry (file) to the changelog folder named {change_type}_{change_description}.md if the new code introduces user-observable changes. See changelog entry format for details.

[bbatsov]

I'd suggest "EnforcedStyle" with the options "Gemfile" and "gems.rb". To me at least, that's much easier to understand.

[dvandersluis]

Absolutely agree, and it's more consistent with other cops that way.

[bbatsov]

Please add backticks around the names of the files, so they are properly colored in the terminal.

[bbatsov]

I see this function uses only the underlying buffer, so I guess you can pass it down directly.

[bbatsov]

I think it's a bit weird that this function might register an offense or not. Perhaps it has to be separated in two for clarity.

[dvandersluis]

I believe you should be able to use add_global_offense instead of the two add_offense calls since the offense isn't really related to a line.

rubocop/lib/rubocop/cop/base.rb

Lines 105 to 112 in 0741555

	# Adds an offense that has no particular location.
	# No correction can be applied to global offenses
	def add_global_offense(message = nil, severity: nil)
	severity = find_severity(nil, severity)
	message = find_message(nil, message)
	@current_offenses <<
	Offense.new(severity, Offense::NO_LOCATION, message, name, :unsupported)
	end

[dvandersluis]

Suggested change

	def gemfile_offense?(file_path)
	gemfile_required? && %w[gems.rb gems.locked].include?(file_path)
	end
	def gemfile_offense?(file_path)
	gemfile_required? && GEMS_RB_FILES.include?(file_path)
	end

[dvandersluis]

Suggested change

	def gems_rb_offense?(file_path)
	gems_rb_required? && %w[Gemfile Gemfile.lock].include?(file_path)
	end
	def gems_rb_offense?(file_path)
	gems_rb_required? && GEMFILE_FILES.include?(file_path)
	end

[dvandersluis]

The other bundler cops handle gem/lock files that aren't in the root directory, but this doesn't appear like it'll do so given how the file names are matched.

[bbatsov]

@gregfletch Ping :-)

[gregfletch]

@gregfletch Ping :-)

Oops, completely forgot about this. Should have time by this weekend to fix up the remaining comments and finish this off. Sorry about that!

[bbatsov]

Seems we're good to go now. Thanks!