Snippet that creates random people from a list of names and surname (json arrays in files) and writes it to a file (json array)

generateJsonNames.js

var fs = require('fs');
var namesIn = "names.json"
var surnamesIn = "surnames.json"
var peopleOut = "peopleOut.json"

var namesFile = fs.readFileSync(namesIn, 'utf8');
var surnamesFile = fs.readFileSync(surnamesIn, 'utf8');

namesJson = JSON.parse(namesFile);
surnamesJson = JSON.parse(surnamesFile);

people = { person: [] }

for (let index = 0; index < 10000; index++) {
    people.person.push( randomPerson(namesJson, surnamesJson));
}

var stringified = JSON.stringify(people);
fs.writeFile(peopleOut, stringified, 'utf8');

function randomPerson(names,surnames){
    var name = randomName(names);
    var surname = randomName(surnames); 
    var ppl = { 'name': name, 'surname': surname }

    return ppl;
}

function randomName(lst){
    if (lst.names != null)
        return lst.names[randomIntFromInterval(0,lst.names.length)]
    else
        return lst.surnames[randomIntFromInterval(0,lst.surnames.length)]
}

function randomIntFromInterval(min,max)
{
    return Math.floor(Math.random()*(max-min+1)+min);
}