##
# excerpt from user.rb

  # this is how roles is defined
  has_and_belongs_to_many :roles

  # and this the has_role? function
  def has_role?(role)
    if role.is_a?(String)
      @@roles ||= {}
      @@roles[role] ||= Role.find_by_title(role)
      role = @@roles[role]
    end
    roles.include?(role) # this is the line of failure, but only when user.roles was not called before
  end

##
# console output

# when calling user.roles before calling has_role? it works fine
>> u = User.find 1
=> #<User id: 1, login: "mk", ....>>>
u.roles
=> [#<Role id: 2, title: "admin">, #<Role id: 5, title: "same-ip">, #<Role id: 4, title: "tester">, #<Role id: 3, title: "user">]
>> u.has_role?('admin')
=> true

# but it crashes when not
>> User.find(1).has_role?('admin')
ActiveRecord::StatementInvalid: TypeError: wrong argument type Hash (expected String): conditions`roles`.`id` = 2sqlSELECT `roles`.id FROM `roles`  INNER JOIN `roles_users` ON `roles`.id = `roles_users`.role_id   WHERE (`roles`.`id` = 2) AND (`roles_users`.user_id = 1 )  LIMIT 1offsetselect`roles`.idlimit1
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb:151:in `log'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb:299:in `execute'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb:499:in `select'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb:7:in `select_all_without_query_cache'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb:55:in `select_all'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/base.rb:579:in `exists?'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:258:in `send'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:258:in `method_missing_without_paginate'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/base.rb:1806:in `with_scope'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/associations/association_proxy.rb:168:in `send'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/associations/association_proxy.rb:168:in `with_scope'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:254:in `method_missing_without_paginate'
        from /home/deploy/sauspiel-rails/vendor/plugins/will_paginate/lib/will_paginate/finder.rb:164:in `method_missing'
        from /home/deploy/sauspiel-rails/vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:218:in `include?'
        from /home/deploy/sauspiel-rails/app/models/user.rb:575:in `has_role?'
        from (irb):15