import assertString from './util/assertString';
export default function ltrim(str, chars) {
  assertString(str); // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#Escaping

  var pattern = chars ? new RegExp("^[".concat(chars.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), "]+"), 'g') : /^\s+/g;
  return str.replace(pattern, '');
}