[Fix rubocop#367] Fix an incorrect autocorrect for `Performance/Block…

…GivenWithExplicitBlock`

Fixes rubocop#367.

This PR fixes an incorrect autocorrect for `Performance/BlockGivenWithExplicitBlock`
when using `Lint/UnusedMethodArgument`'s autocorrection together.

changelog/fix_an_incorrect_autocorrect_for_performance_block_given_with_explicit_block.md

@@ -0,0 +1 @@
+* [#367](https://github.com/rubocop/rubocop-performance/issues/367): Fix an incorrect autocorrect for `Performance/BlockGivenWithExplicitBlock` when using `Lint/UnusedMethodArgument`'s autocorrection together. ([@ymap][])

lib/rubocop-performance.rb

@@ -9,3 +9,11 @@
 RuboCop::Performance::Inject.defaults!
 
 require_relative 'rubocop/cop/performance_cops'
+
+RuboCop::Cop::Lint::UnusedMethodArgument.singleton_class.prepend(
+  Module.new do
+    def autocorrect_incompatible_with
+      super.push(RuboCop::Cop::Performance::BlockGivenWithExplicitBlock)
+    end
+  end
+)

lib/rubocop/cop/performance/block_given_with_explicit_block.rb

@@ -47,6 +47,10 @@ def on_send(node)
             corrector.replace(node, block_arg_name)
           end
         end
+
+        def self.autocorrect_incompatible_with
+          [Lint::UnusedMethodArgument]
+        end
       end
     end
   end

spec/rubocop/cli/autocorrect_spec.rb

@@ -30,6 +30,23 @@
     RUBY
   end
 
+  it 'corrects `Performance/BlockGivenWithExplicitBlock` with `Lint/UnusedMethodArgument`' do
+    source = <<~RUBY
+      def foo(&block)
+        block_given?
+      end
+    RUBY
+    create_file('example.rb', source)
+    expect(
+      cli.run(['--autocorrect', '--only', 'Performance/BlockGivenWithExplicitBlock,Lint/UnusedMethodArgument'])
+    ).to eq(0)
+    expect(File.read('example.rb')).to eq(<<~RUBY)
+      def foo()
+        block_given?
+      end
+    RUBY
+  end
+
   private
 
   def create_file(file_path, content)