[Fix #543] Fix an error for Rails/ContentTag

Fixes #543.

This PR fixes an error for `Rails/ContentTag` when `tag` is not a top-level method.

Author: koic

changelog/fix_error_for_rails_content_tag.md

@@ -0,0 +1 @@
+* [#543](https://github.com/rubocop/rubocop-rails/issues/543): Fix an error for `Rails/ContentTag` when `tag` is not a top-level method. ([@koic][])

lib/rubocop/cop/rails/content_tag.rb

@@ -33,6 +33,8 @@ def on_new_investigation
         end
 
         def on_send(node)
+          return unless node.receiver.nil?
+
           first_argument = node.first_argument
           return if !first_argument ||
                     allowed_argument?(first_argument) ||
@@ -41,12 +43,7 @@ def on_send(node)
           preferred_method = node.first_argument.value.to_s.underscore
           message = format(MSG, preferred_method: preferred_method, current_argument: first_argument.source)
 
-          add_offense(node, message: message) do |corrector|
-            autocorrect(corrector, node, preferred_method)
-
-            @corrected_nodes ||= Set.new.compare_by_identity
-            @corrected_nodes.add(node)
-          end
+          register_offense(node, message, preferred_method)
         end
 
         private
@@ -63,6 +60,15 @@ def allowed_argument?(argument)
             allowed_name?(argument)
         end
 
+        def register_offense(node, message, preferred_method)
+          add_offense(node, message: message) do |corrector|
+            autocorrect(corrector, node, preferred_method)
+
+            @corrected_nodes ||= Set.new.compare_by_identity
+            @corrected_nodes.add(node)
+          end
+        end
+
         def autocorrect(corrector, node, preferred_method)
           range = correction_range(node)
 

spec/rubocop/cop/rails/content_tag_spec.rb

@@ -168,5 +168,13 @@
         RUBY
       end
     end
+
+    context 'when `tag` is not a top-level method (e.g. using intercom-ruby)' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          intercom.tags.tag(foo: 'foo', bar: 'bar')
+        RUBY
+      end
+    end
   end
 end