Js Customizable Random Table generator

tableGenerator.js

(function() {
    function zeroFill(str, len, char) {
        if ((str+"").length < len) {
            return Array(len-(str+"").length).fill(char)+(str+"")
        }
        return (str+"")
    }

    function withVerifierDigits(numbers) {
        numbers = numbers+""
        function v(n) {
            n = (n+"")
                .split("")
                .map(function(number){ return parseInt(number, 10); })
            ;

            var modulus = n.length + 1;

            var multiplied = n.map(function(number, index) {
                return number * (modulus - index);
            });

            var mod = multiplied.reduce(function(buffer, number){
                return buffer + number;
            }) % 11;

            return (mod < 2 ? 0 : 11 - mod);
        }
        return numbers+v(numbers)+v(numbers+v(numbers))
    }

    var columnGen = {
        float: function(min=0, max=100) {
            return function() {
                return (Math.random() * (max - min) + min)
            }
        },
        int: function(min=0, max=100) {
            return function() {
                return (Math.floor(Math.random() * (max - min + 1) + min))
            }
        },
        text: function(names) {
            return function() {
                if (names == null) {
                    return (Math.round(Math.random()*10)*1000000000).toString(32).toUpperCase()
                } else {
                    return (names[Math.floor(Math.random() * names.length)])
                }
            }
        },
        date: function() {
            return function() {
                return new Date( columnGen.int(-628466400000, 2527293600000)() )
            }
        },
        dateDMY: function() {
            return function() {
                var x = columnGen.date()()
                return zeroFill(x.getDate(), 2, "0") + "/" + 
                    zeroFill(x.getMonth()+1, 2, "0") + "/" +
                    zeroFill(x.getFullYear(), 4, "0")
            }
        },
        dateYMD:function() {
            return function() {
                var x = columnGen.date()()
                return zeroFill(x.getFullYear(), 4, "0") + "-" + 
                    zeroFill(x.getMonth()+1, 2, "0") + "-" +
                    zeroFill(x.getDate(), 2, "0")
            }
        },
        dateISON:function() {
            return function() {
                var x = columnGen.date()().toISOString()
            }
        },
        cpf: function(withDots=false, withValidator=false) {
            return function() {
                var cpf = columnGen.int(100000000, 999999999)()+""
                
                if (withValidator) {
                    cpf = withVerifierDigits(cpf)
                    if (withDots) {
                        cpf = cpf.replace(/(.{3})(.{3})(.{3})(.{2})/, "$1.$2.$3-$4")
                    }
                } else {
                    if (withDots) {
                        cpf = cpf.replace(/(.{3})(.{3})(.{3})/, "$1.$2.$3")
                    }
                }
                return cpf
            }
        },
    }

    return {
        generators: columnGen,
        generate: function(_cfg) {

            var cfg = {
                size: _cfg.size == null ? 15 : (isNaN(_cfg.size) ? 15 : parseInt(_cfg.size)),
                columns: (_cfg.columns == null ? [] : _cfg.columns).map(function(col, i) {
                    return {
                        name: col.name == null ? function(i, size) { return "Column "+(i+1)+" of "+size } : col.name,
                        gen: col.gen == null ? function() {return null} : col.gen
                    }
                })
            }

            var size = typeof cfg.size === "function" ? cfg.size() : cfg.size
            var columnLength = cfg.columns.length

            return Array( size+1 ).fill().map(function( _, i) {
                if (i === 0) {
                    return cfg.columns.map(function(col, j) {
                        return (typeof col.name === "function" ? col.name(j, columnLength) : col.name)
                    })
                } else {
                    return cfg.columns.map(function(col, j) {
                        return col.gen(i, j, size, columnLength)
                    })
                }
            })
        }

    }
})()