[Fix rubocop#6761] Make UncommunicativeMethodParamName account for un…

…derscores.

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Bug fixes
 
+* [#6761](https://github.com/rubocop-hq/rubocop/issues/6761): Make `Naming/UncommunicativeMethodParamName` account for param names prefixed with underscores. ([@thomthom][])
 * [#6855](https://github.com/rubocop-hq/rubocop/pull/6855): Fix an exception in `Rails/RedundantReceiverInWithOptions` when the body is empty. ([@ericsullivan][])
 * [#6856](https://github.com/rubocop-hq/rubocop/pull/6856): Fix auto-correction for `Style/BlockComments` when the file is missing a trailing blank line. ([@ericsullivan][])
 * [#6858](https://github.com/rubocop-hq/rubocop/issues/6858): Fix an incorrect auto-correct for `Lint/ToJSON` when there are no `to_json` arguments. ([@koic][])
@@ -3895,3 +3896,4 @@
 [@ericsullivan]: https://github.com/ericsullivan
 [@aeroastro]: https://github.com/aeroastro
 [@anuja-joshi]: https://github.com/anuja-joshi
+[@thomthom]: https://github.com/thomthom

lib/rubocop/cop/mixin/uncommunicative_name.rb

@@ -13,7 +13,12 @@ module UncommunicativeName
 
       def check(node, args)
         args.each do |arg|
-          name = arg.children.first.to_s
+          # Argument names might be "_" or prefixed with "_" to indicate they
+          # are unused. Trim away this prefix and only analyse the basename.
+          full_name = arg.children.first.to_s
+          next if full_name == '_'
+
+          name = full_name.gsub(/\A([_]+)/, '')
           next if (arg.restarg_type? || arg.kwrestarg_type?) && name.empty?
           next if allowed_names.include?(name)
 

spec/rubocop/cop/naming/uncommunicative_method_param_name_spec.rb

@@ -147,6 +147,22 @@ def quux(foo1, foo2)
       RUBY
     end
 
+    it 'accepts param names prefixed with underscore' do
+      expect_no_offenses(<<-RUBY.strip_indent)
+        def quux(_foo1, _foo2)
+          do_stuff
+        end
+      RUBY
+    end
+
+    it 'accepts underscore param names' do
+      expect_no_offenses(<<-RUBY.strip_indent)
+        def quux(_)
+          do_stuff
+        end
+      RUBY
+    end
+
     it 'registers unlisted offensive names' do
       expect_offense(<<-RUBY.strip_indent)
         def quux(bar, bar1)