Ignore if number of arguments does not match on Rails/DynamicFindBy

changelog/change_ignore_if_number_of_arguments_does_not_match.md

@@ -0,0 +1 @@
+* [#862](https://github.com/rubocop/rubocop-rails/pull/862): Ignore if number of arguments does not match on `Rails/DynamicFindBy`. ([@r7kamura][])

lib/rubocop/cop/rails/dynamic_find_by.rb

@@ -53,7 +53,7 @@ def on_send(node)
           method_name = node.method_name
           static_name = static_method_name(method_name)
           return unless static_name
-          return if node.arguments.any? { |argument| IGNORED_ARGUMENT_TYPES.include?(argument.type) }
+          return unless dynamic_find_by_arguments?(node)
 
           message = format(MSG, static_name: static_name, method: method_name)
           add_offense(node, message: message) do |corrector|
@@ -65,12 +65,8 @@ def on_send(node)
         private
 
         def autocorrect(corrector, node)
-          keywords = column_keywords(node.method_name)
-
-          return if keywords.size != node.arguments.size
-
           autocorrect_method_name(corrector, node)
-          autocorrect_argument_keywords(corrector, node, keywords)
+          autocorrect_argument_keywords(corrector, node, column_keywords(node.method_name))
         end
 
         def allowed_invocation?(node)
@@ -120,6 +116,20 @@ def static_method_name(method_name)
 
           match[2] ? 'find_by!' : 'find_by'
         end
+
+        def dynamic_find_by_arguments?(node)
+          dynamic_find_by_arguments_count?(node) && dynamic_find_by_arguments_type?(node)
+        end
+
+        def dynamic_find_by_arguments_count?(node)
+          column_keywords(node.method_name).size == node.arguments.size
+        end
+
+        def dynamic_find_by_arguments_type?(node)
+          node.arguments.none? do |argument|
+            IGNORED_ARGUMENT_TYPES.include?(argument.type)
+          end
+        end
       end
     end
   end

spec/rubocop/cop/rails/dynamic_find_by_spec.rb

@@ -105,24 +105,18 @@
   end
 
   context 'with too much arguments' do
-    it 'registers an offense and no corrects' do
-      expect_offense(<<~RUBY)
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY)
         User.find_by_name_and_email(name, email, token)
-        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `find_by` instead of dynamic `find_by_name_and_email`.
       RUBY
-
-      expect_no_corrections
     end
   end
 
   context 'with too few arguments' do
-    it 'registers an offense and no corrects' do
-      expect_offense(<<~RUBY)
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY)
         User.find_by_name_and_email(name)
-        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Use `find_by` instead of dynamic `find_by_name_and_email`.
       RUBY
-
-      expect_no_corrections
     end
   end