class RuboCop::Cop::Layout::SpaceInsideReferenceBrackets

def left_ref_bracket(node, tokens)
  current_token = tokens.reverse.find(&:left_ref_bracket?)
  previous_token = previous_token(current_token)
  if node.method?(:[]=) || (previous_token && !previous_token.right_bracket?)
    tokens.find(&:left_ref_bracket?)
  else
    current_token
  end
end