Make Rails/DynamicFindBy aware of safe navigation operator

Author: hoshinotsuyoshi

lib/rubocop/cop/rails/dynamic_find_by.rb

@@ -42,6 +42,7 @@ def on_send(node)
                       message: format(MSG, static_name: static_name,
                                            method: node.method_name))
         end
+        alias on_csend on_send
 
         def autocorrect(node)
           keywords = column_keywords(node.method_name)

spec/rubocop/cop/rails/dynamic_find_by_spec.rb

@@ -138,4 +138,16 @@
       User.find_by_sql(["select * from users where name = ?", name])
     RUBY
   end
+
+  context 'when using safe navigation operator', :ruby23 do
+    context 'with dynamic find_by_*' do
+      let(:source) { 'user&.find_by_name(name)' }
+
+      include_examples(
+        'register an offense and auto correct',
+        'Use `find_by` instead of dynamic `find_by_name`.',
+        'user&.find_by(name: name)'
+      )
+    end
+  end
 end