class RuboCop::Cop::Layout::MultilineMethodArgumentLineBreaks

)
c
b,
a,
foo(
# good
)
c
foo(a, b,
# bad
@example
starts on a separate line.
This cop ensures that each argument in a multi-line method call

def on_send(node) 

def on_send(node)
  return if node.method?(:[]=)
  args = node.arguments
  # If there is a trailing hash arg without explicit braces, like this:
  #
  #    method(1, 'key1' => value1, 'key2' => value2)
  #
  # ...then each key/value pair is treated as a method 'argument'
  # when determining where line breaks should appear.
  last_arg = args.last
  args = args[0...-1] + last_arg.children if last_arg&.hash_type? && !last_arg&.braces?
  check_line_breaks(node, args)
end