random-token/index.js

void function(root){

    // return a number between 0 and max-1
    function r(max){ return Math.floor(Math.random()*max) }

    function generate(salt, size){
        var key = ''
        var sl = salt.length
        while ( size -- ) {
            var rnd = r(sl)
            key += salt[rnd]
        }
        return key
    }

    var rndtok = function(salt, size){
        return isNaN(size) ? undefined :
               size < 1    ? undefined : generate(salt, size)

    }

    function createGenerator(salt){
        salt = typeof salt  == 'string' && salt.length > 0 ? salt :  'abcdefghijklmnopqrstuvwxzy0123456789'
        var temp = rndtok.bind(rndtok, salt)
        temp.salt = function(){ return salt }
        temp.create = createGenerator
        return temp
    }

    rndtok.gen = createGenerator

    module.exports = createGenerator()

}(this)