Validar CNPJ (TS)

validaCNPJ.ts

export function ValidaCNPJ(cnpj: string): boolean {
  const b: number[] = [6, 5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2];
  const c: string = cnpj.replace(/[^\d]/g, '');

  if (c.length !== 14) {
    return false;
  }

  if (/0{14}/.test(c)) {
    return false;
  }

  let n: number = 0;
  for (let i = 0; i < 12; n += Number(c[i]) * Number(b[++i]));
  if (c[12] !== ((n %= 11) < 2 ? '0' : (11 - n).toString())) {
    return false;
  }

  n = 0;
  for (let i = 0; i <= 12; n += Number(c[i]) * Number(b[i++]));
  if (c[13] !== ((n %= 11) < 2 ? '0' : (11 - n).toString())) {
    return false;
  }

  return true;
}