Implementation of a stack and cheaty stack in JavaScript. (NOTE: I stupidly deleted my testing code... I need to rewrite it (better) and put it back in. Apologies!)

js_stack.js

var assert = require("assert"); // node needs this module


// CHEATING STACK (using built-in functions):
function CheatingStack () {
  this.contents = [];
}
CheatingStack.prototype.push = function (item) {
	this.contents.push(item);
};
CheatingStack.prototype.pop = function () {
	return this.contents.pop();
}
CheatingStack.prototype.isEmpty = function () {
	return (this.contents.length === 0);
}


// STACK using only objects:
function Item (value, prevItem) {
	this.value = value;
	this.prevItem = prevItem;
}

function LinkedListStack () {
	this.head = null;
}
LinkedListStack.prototype.push = function (item) {
	var newItem = new Item (item, this.head);
	this.head = newItem;
}; 
LinkedListStack.prototype.pop = function() {
	if (this.isEmpty()) {
		return false;
	} 
	else {
		var returnItem = this.head;
		this.head = returnItem.prevItem;
		return returnItem.value;
	}
}
LinkedListStack.prototype.isEmpty = function() {
	return (this.head === null);
}






// CLIENT CODE: testing our implementation

var myStack = new LinkedListStack();


// Yes... I deleted my testing code because it was imperfect. Yes, I need to rewrite it and put it back in. Perhaps after I finish writing about what I just learned!