Convert a number to a string with n leading zeroes.
Using @Pointy's answer on Stackoverflow.
$ npm install pad-number
var pad = require('pad-number');
console.log(pad(10, 4)); // '0010'
console.log(pad(10, 5)); // '00010'
console.log(pad(10, 1)); // '10'
// Optional padding character:
console.log(pad(10, 5, '-')); // '---10'
MIT