class Rubocop::Cop::WordArray

def complex_content?(arr_sexp)
  arr_sexp.each do |s|
    str_content = Util.strip_quotes(s.loc.expression.source)
    return true unless str_content =~ /\A[\w-]+\z/
  end
  false
end

def on_array(node)
  return unless node.loc.begin && node.loc.begin.source == '['
  array_elems = node.children
  # no need to check empty arrays
  return unless array_elems && array_elems.size > 1
  string_array = array_elems.all? { |e| e.type == :str }
  if string_array && !complex_content?(array_elems)
    add_offence(:convention, node.loc.line, MSG)
  end
  super
end