class RuboCop::Cop::Rails::DefaultScope

default_scope { something }
# correct
default_scope -> { something }
# incorrect
@example
a lambda or a proc instead of a block.
This cop checks for default_scope calls when it was passed

def on_send(node) 

def on_send(node)
  return unless command?(:default_scope, node)
  _receiver, _method_name, *args = *node
  return unless args.size == 1
  first_arg = args[0]
  return unless first_arg.type != :block || lambda_or_proc?(first_arg)
  add_offense(first_arg, :expression)
end