class RuboCop::Cop::Layout::SpaceBeforeFirstArg

def on_send(node)
  return unless regular_method_call_with_arguments?(node)
  return unless expect_params_after_method_name?(node)
  first_arg = node.first_argument.source_range
  first_arg_with_space = range_with_surrounding_space(range: first_arg,
                                                      side: :left)
  space = range_between(first_arg_with_space.begin_pos,
                        first_arg.begin_pos)
  add_offense(space, location: space) if space.length != 1
end