class RuboCop::Cop::Layout::SpaceInsideStringInterpolation

def on_interpolation(begin_node)
  return if begin_node.multiline?
  tokens = processed_source.tokens_within(begin_node)
  left, right = delimiters(begin_node)
  return if empty_brackets?(left, right, tokens: tokens)
  if style == :no_space
    no_space_offenses(begin_node, left, right, MSG)
  else
    space_offenses(begin_node, left, right, MSG)
  end
end