Validação de CPF em JavaScript, padrão funcional, ideal para usar com React.js

validate_CPF.py

from django.core.validators import RegexValidator
from functools import reduce
import re

verify_sum = lambda cpf, last_index: reduce(
        lambda total, el, index: total + (el * (index + 2)),
        cpf.reverse()[0:last_index], 0)
def verify_rest(sum: int, digit: int):
    rest = (sum * 10) % 11
    new_rest = 0 if ((rest == 10) or (rest == 11)) else rest
    return new_rest == digit

def validate_cpf(value: str):
    unmasked_cpf = re.sub('[\s.-]*', '', value)
    array_cpf = map(lambda el: int(el), value.split(''))
    RegexValidator('(\d)\1{10}')(unmasked_cpf)
    if (not unmasked_cpf or unmasked_cpf.length != 11): 
        return False
    first_sum = verify_sum(array_cpf, 9)
    second_sum = verify_sum(array_cpf, 10)
    return verify_rest(first_sum, array_cpf[9]) and verify_rest(second_sum, array_cpf[10])

validateCPF.ts

const verifySum = (cpf: number[], lastIndex: number): number => cpf
    .slice(0, lastIndex)
    .reverse()
    .reduce((total, current, index) => total + (current * (index + 2)), 0);
const verifyRest = (sum: number, digit: number) => {
    const rest = (sum * 10) % 11;
    const newRest = ((rest == 10) || (rest == 11)) ? 0 : rest;
    return newRest == digit;
}
export const validateCPF = (cpf: string) => {
    if (typeof cpf !== "string") return false;
    const unmaskedCPF = cpf.replace(/[\s.-]*/igm, '');
    const arrayCPF = unmaskedCPF.split('').map(value => parseInt(value));
    if (
        !unmaskedCPF ||
        unmaskedCPF.length != 11 ||
        /(\d)\1{10}/.test(unmaskedCPF)
    ) return false;
    const firstSum = verifySum(arrayCPF, 9);
    const secondSum = verifySum(arrayCPF, 10);
    return verifyRest(firstSum, arrayCPF[9]) && verifyRest(secondSum, arrayCPF[10]);
}