Bug in Rails/UniqueValidationWithoutIndex cop

[tbk303]

1 error occurred:
An error occurred while Rails/UniqueValidationWithoutIndex cop was inspecting 

undefined method `with_column?' for nil:NilClass
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-rails-2.8.0/lib/rubocop/cop/mixin/active_record_helper.rb:55:in `resolve_relation_into_column'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-rails-2.8.0/lib/rubocop/cop/rails/unique_validation_without_index.rb:84:in `block in column_names'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-rails-2.8.0/lib/rubocop/cop/rails/unique_validation_without_index.rb:82:in `map!'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-rails-2.8.0/lib/rubocop/cop/rails/unique_validation_without_index.rb:82:in `column_names'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-rails-2.8.0/lib/rubocop/cop/rails/unique_validation_without_index.rb:50:in `find_schema_information'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-rails-2.8.0/lib/rubocop/cop/rails/unique_validation_without_index.rb:38:in `on_send'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:99:in `block (2 levels) in trigger_responding_cops'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:152:in `with_cop_error_handling'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:98:in `block in trigger_responding_cops'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:97:in `each'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:97:in `trigger_responding_cops'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:70:in `on_send'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-ast-0.4.0/lib/rubocop/ast/traversal.rb:59:in `block in on_begin'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-ast-0.4.0/lib/rubocop/ast/traversal.rb:59:in `each'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-ast-0.4.0/lib/rubocop/ast/traversal.rb:59:in `on_begin'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:72:in `on_begin'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-ast-0.4.0/lib/rubocop/ast/traversal.rb:101:in `on_class'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:72:in `on_class'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-ast-0.4.0/lib/rubocop/ast/traversal.rb:14:in `walk'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/commissioner.rb:85:in `investigate'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/team.rb:152:in `investigate_partial'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cop/team.rb:83:in `investigate'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:311:in `inspect_file'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:255:in `block in do_inspection_loop'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:289:in `block in iterate_until_no_changes'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:282:in `loop'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:282:in `iterate_until_no_changes'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:251:in `do_inspection_loop'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:128:in `block in file_offenses'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:153:in `file_offense_cache'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:127:in `file_offenses'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:118:in `process_file'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:97:in `block in each_inspected_file'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:96:in `each'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:96:in `reduce'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:96:in `each_inspected_file'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:82:in `inspect_files'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/runner.rb:43:in `run'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cli/command/execute_runner.rb:25:in `execute_runner'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cli/command/execute_runner.rb:17:in `run'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cli/command.rb:11:in `run'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cli/environment.rb:18:in `run'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cli.rb:65:in `run_command'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cli.rb:72:in `execute_runners'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/lib/rubocop/cli.rb:41:in `run'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/exe/rubocop:13:in `block in <top (required)>'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/2.7.0/benchmark.rb:308:in `realtime'
/home/tbk/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/rubocop-0.91.0/exe/rubocop:12:in `<top (required)>'
/home/tbk/.rbenv/versions/2.7.1/bin/rubocop:23:in `load'
/home/tbk/.rbenv/versions/2.7.1/bin/rubocop:23:in `<main>'
.

1 file inspected, no offenses detected

1 error occurred:
An error occurred while Rails/UniqueValidationWithoutIndex cop was inspecting 

The file/validation in question is this:

  validates :voter_id, uniqueness: {
    scope: %i[voteable_id voteable_type],
    message: 'darf nur ein mal abstimmen',
  }

---

RuboCop version

 $ rubocop -V  
0.91.0 (using Parser 2.7.1.4, rubocop-ast 0.4.0, running on ruby 2.7.1 x86_64-linux)

[tbk303]

Sorry, closing this as dup of #348

[koic]

@tbk303 RuboCop Rails 2.8.1 has been released. Can you upgrade to the latest RuboCop Rails? Thank you for your feedback.