Javascript Cyclic Nested Object Property Search

findObjProperty.js

/*
 *  Finds locations within data structure that a specific key/value can be found
 *    - Handles looping data structures (for instance window.window = window)
 *    - Flexible query format (provide key to match, value to match, or both)
 *    - Handy for reverse engineering and understanding javascript code on websites
 *    - Note, it's a little hack-ish, but it's just a tool anyway
 *  Examples:
 *    a = {b: 4, c: [1, 2, {d: 5, e: [0, 5, 2]}]};
 *    searchObj(a, {key: d});           // --> ["root.c.2.d"]
 *    searchObj(a, {value: 2});         // --> ["root.c.1", "root.c.2.e.2"]
 *    searchObj(a, {key: 1, value: 2}); // --> ["root.c.1"]
**/

var searchObj = (function () {
  var uniqueId = 0;
  return function(obj, query) {
  	if (!("key" in query || "value" in query)) return -1;
  	var stack = [[["root", obj]]];	// remaining tree to traverse
  	var objStack = [];	// current object path
  	var i;
  	var visited = {};	// handle cycles
  	result = [];		// object paths found
  
  	function addResult(last) {
  		var i, r = [];
  		for (i in objStack) r.push(objStack[i]);
  		r.push(last);
  		result.push(r.join("."));
  	}
  
  	while (stack.length > 0) {
  		if (stack[stack.length-1].length == 0) {
  			stack.pop();
  			if (objStack.length) objStack.pop();
  			continue;
  		}
  		obj = stack[stack.length-1].pop();
  		if (!obj[1].hasOwnProperty('unique_id')) Object.defineProperty(obj[1], 'unique_id', {value: uniqueId++}); // non-iterable property
  		visited[obj[1].unique_id] = true;
  		objStack.push(obj[0]);
  		stack.push([]);
  		for (var t in Object.getOwnPropertyNames(obj[1])) {
  			i = Object.getOwnPropertyNames(obj[1])[t];
  			try {
  				if ((!("key" in query) || query["key"] == i) &&
  				    (!("value" in query) || query["value"] == obj[1][i]))
  				    addResult(i);
  				if (typeof(obj[1][i]) == "object" && obj[1][i] != null && (!("unique_id" in obj[1][i]) || !visited[obj[1][i].unique_id])) {
  					stack[stack.length-1].push([i, obj[1][i]]);
  				}
  			} catch (exception) {
  				console.log("Caught exception on " + objStack.concat([i]).join(".") + ": " + exception);
  			}
  		}
  	}
  	return result;
}})();