Nodejs Utililty Methods String Split

String.prototype.splitFirst = function (separator) {
    var si = this.split(separator);
    var output = [];
    output.push(si[0]);
    if (si.length>1) {
        si.shift();
        output.push(si.join(separator));
    return output;
...

String.prototype.splitFirst = function(x){
  var index = this.indexOf(x);
  return [
    this.substring(0, index),
    this.substring(index + x.length)
  ]
};

String.prototype.splitLast = function(separator) {
    var si = this.split(separator);
    var output = [];
    var last = si.pop();
    if (si.length > 0) {
        output.push(si.join(separator));
    if (last) {
        output.push(last);
...

String.prototype.splitLength = function(size) {
    var regex = new RegExp('.{1,' + size + '}', 'g');
    return this.match(regex);
};

String.prototype.splitLines = function (splitOptions = { removeEmptyEntries: true, trim: true }) {
    let lines = this.split(/\r?\n/g);
    if (splitOptions && splitOptions.trim) {
        lines = lines.filter(line => line.trim());
    if (splitOptions && splitOptions.removeEmptyEntries) {
        lines = lines.filter(line => line.length > 0);
    return lines;
...

String.prototype.splitOnce = function (delimiter) {
    var components = this.split(delimiter);
    return [components.shift(), components.join(delimiter)];
};
if (!String.prototype.endsWith) {
  String.prototype.endsWith = function(searchString, position) {
      var subjectString = this.toString();
      if (position === undefined || position > subjectString.length) {
          position = subjectString.length;
...

String.prototype.splitOnce = function (regex) {
    var match = this.match(regex);
    if (match) {
        var match_i = this.indexOf(match[0]);
        return [this.substring(0, match_i),
        this.substring(match_i + match[0].length)];
    } else {
        return [this, ""];

function reverseWords(str) {
  var result = "";
  var wordArray = str.split(" ");
  for (var i = wordArray.length - 1; i >= 0; i--) {
    result += wordArray[i] + " ";
  return result.trim(); 
String.prototype.splitStr = function (delimiter) {
...

String.prototype.splitWord = function () {
  return this.split(/(?=[A-Z])/).join(' ');
};

String.prototype.splitchunks = function(s) {
  return s.split(/\n\n+/)