Merge pull request #297 from r7kamura/feature/redundant-match

Support autocorrection on `Performance/RedundantMatch` when receiver is a Regexp literal

changelog/change_support_autocorrection_on_redundantmatch.md

@@ -0,0 +1 @@
+* [#297](https://github.com/rubocop/rubocop-performance/pull/297): Support autocorrection on `Performance/RedundantMatch` when receiver is a Regexp literal. ([@r7kamura][])

lib/rubocop/cop/performance/redundant_match.rb

@@ -41,21 +41,23 @@ def on_send(node)
                         !(node.parent && node.parent.block_type?)
 
           add_offense(node) do |corrector|
-            autocorrect(corrector, node)
+            autocorrect(corrector, node) if autocorrectable?(node)
           end
         end
 
         private
 
         def autocorrect(corrector, node)
-          # Regexp#match can take a second argument, but this cop doesn't
-          # register an offense in that case
-          return unless node.first_argument.regexp_type?
-
           new_source = "#{node.receiver.source} =~ #{node.first_argument.source}"
 
           corrector.replace(node.source_range, new_source)
         end
+
+        def autocorrectable?(node)
+          # Regexp#match can take a second argument, but this cop doesn't
+          # register an offense in that case
+          node.receiver.regexp_type? || node.first_argument.regexp_type?
+        end
       end
     end
   end

spec/rubocop/cop/performance/redundant_match_spec.rb

@@ -111,4 +111,15 @@ def method(str)
                    ^^^^^^^^^^^^^^^^^^ Use `=~` in places where the `MatchData` returned by `#match` will not be used.
     RUBY
   end
+
+  it 'registers an offense and corrects when receiver is a Regexp literal' do
+    expect_offense(<<~RUBY)
+      something if /regex/.match(str)
+                   ^^^^^^^^^^^^^^^^^^ Use `=~` in places where the `MatchData` returned by `#match` will not be used.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      something if /regex/ =~ str
+    RUBY
+  end
 end