[Fix #1377] Fix an error for Rails/EnumSyntax

Fixes #1377

This PR fixes an error for `Rails/EnumSyntax`
when positional arguments are used and options are not passed as keyword arguments.

changelog/fix_an_error_for_rails_enum_syntax.md

@@ -0,0 +1 @@
+* [#1377](https://github.com/rubocop/rubocop-rails/issues/1377): Fix an error for `Rails/EnumSyntax` when positional arguments are used and options are not passed as keyword arguments. ([@koic][])

lib/rubocop/cop/rails/enum_syntax.rb

@@ -106,6 +106,8 @@ def enum_name(elem)
         end
 
         def option_key?(pair)
+          return false unless pair.respond_to?(:key)
+
           UNDERSCORED_OPTION_NAMES.include?(pair.key.source)
         end
 

spec/rubocop/cop/rails/enum_syntax_spec.rb

@@ -146,6 +146,14 @@
         expect_no_offenses('enum')
       end
     end
+
+    context 'when positional arguments are used and options are not passed as keyword arguments' do
+      it 'does not register an offense' do
+        expect_no_offenses(<<~RUBY)
+          enum :status, { clow: 1 }, prefix
+        RUBY
+      end
+    end
   end
 
   context 'Rails >= 7.0 and Ruby <= 2.7', :rails70, :ruby27, unsupported_on: :prism do