A set of scripts for generating good or bad israeli phone numbers and ids (JS)

isr_ids.js

function sum(arr) {
    return arr.reduce((partialSum, a) => partialSum + a, 0);
}

Array.prototype.repeat = function(n){
    var a = [];
    for (var i=0;i<n;[i++].push.apply(a,this));
    return a;
  }

const ONE_TWO = [1,2, 1,2, 1,2, 1,2, 1]

function validate_id(checkid) {
    let checkidstr = "0".repeat(9 - checkid.length) + checkid

    let multiplied = [0].repeat(9);
    for(let i = 0; i < 9; i++) {
        multiplied[i] = parseInt(checkidstr[i]) * ONE_TWO[i];
        if(multiplied[i] > 9) {
            let asstr = multiplied[i] + "";
            let sum_asstr = 0;
            for(let num of asstr) {
                sum_asstr += parseInt(num);
            }
            multiplied[i] = sum_asstr;
        }
    }
    let summed_multiplied = sum(multiplied);
    if (summed_multiplied % 10 === 0) {
        return true;
    }
    return false;
}

function generate_id() {
    let id = Math.floor(Math.random() * 1000000000);
    while(!validate_id(id)) {
        id = Math.floor(Math.random() * 1000000000);
    }
    return id;
}