import { isDefined } from './isDefined';

export function isURL(url: string | undefined | null) {
  const pattern = new RegExp(
    '^(https?:\\/\\/)?' +
      '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|' +
      '((\\d{1,3}\\.){3}\\d{1,3}))' +
      '(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*' +
      '(\\?[;&a-z\\d%_.~+=-]*)?' +
      '(\\#[-a-z\\d_]*)?$',
    'i',
  );
  return isDefined(url) && !!pattern.test(url);
}