eligrey/isObjectLiteral.html

## isObjectLiteral.html
<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8"/>
	<!-- Online here: http://code.eligrey.com/testcases/all/isObjectLiteral.html -->
	<title>isObjectLiteral</title>
	<style type="text/css">
	li { background: green; } li.FAIL { background: red; }
	iframe { display: none; }
	</style>
</head>
<body>
<ul id="results"></ul>
<script type="text/javascript">
function isObjectLiteral(obj) {
	if (typeof obj !== "object" || obj === null)
		return false;

	var hasOwnProp = Object.prototype.hasOwnProperty,
	ObjProto = obj;

	while (true) // get obj's Object constructor's prototype
		if (Object.getPrototypeOf(ObjProto = Object.getPrototypeOf(ObjProto)) === null)
			break;

	if (Object.getPrototypeOf(obj) !== ObjProto)
		return false

	else if (!Object.getPrototypeOf.isNative) // workaround if non-native Object.getPrototypeOf
		for (var prop in obj)
			if (!hasOwnProp.call(obj, prop) && !hasOwnProp.call(ObjProto, prop)) // inherited elsewhere
				return false;

	return true;
};


if (!Object.getPrototypeOf) {
	if (typeof this.__proto__ === "object") {
		Object.getPrototypeOf = function (obj) {
			return obj.__proto__;
		};
		Object.getPrototypeOf.isNative = true;
	} else {
		Object.getPrototypeOf = function (obj) {
			var constructor = obj.constructor,
			oldConstructor;
			if (Object.prototype.hasOwnProperty.call(obj, "constructor")) {
				oldConstructor = constructor;
				if (!(delete obj.constructor)) // reset constructor
					return null; // can't delete obj.constructor, return null
				constructor = obj.constructor; // get real constructor
				obj.constructor = oldConstructor; // restore constructor
			}
			return constructor ? constructor.prototype : null; // needed for IE
		};
		Object.getPrototypeOf.isNative = false;
	}
} else if (!("isNative" in Object.getPrototypeOf))
	Object.getPrototypeOf.isNative = true;

// Function serialization is not permitted
// Does not work across all browsers
Function.prototype.toString = function(){};

// The use case that we want to match
log("{}", {}, true);

// Instantiated objects shouldn't be matched
log("new Date", new Date, false);

var fn = function(){};

// Makes the function a little more realistic
// (and harder to detect, incidentally)
fn.prototype = {someMethod: function(){}};

// Functions shouldn't be matched
log("fn", fn, false);

// Again, instantiated objects shouldn't be matched
log("new fn", new fn, false);

var fn2 = function(){};

fn.prototype.someMethod = function(){};

log("new fn2", new fn2, false);

var fn3 = function(){};

fn3.prototype = {}; // impossible to detect (?) without native Object.getPrototypeOf

log("new fn3 (only passes with native Object.getPrototypeOf)", new fn3, false);

log("null", null, false);

log("undefined", undefined, false);


/* Note:
 * The restriction against instantiated functions is
 * due to the fact that this method will be used for
 * deep-cloning an object. Instantiated objects will
 * just have their reference copied over, whereas
 * plain objects will need to be completely cloned.
 */

var iframe = document.createElement("iframe");
document.body.appendChild(iframe);

var doc = iframe.contentDocument || iframe.contentWindow.document;
doc.open();
doc.write("<body onload='window.top.iframeDone(Object);'>");
doc.close();

function iframeDone(otherObject){
	// Objects from other windows should be matched
	log("new otherObject", new otherObject, true);
}

function log(msg, a, b) {
  var pass = isObjectLiteral(a) === b ? "PASS" : "FAIL";

  document.getElementById("results").innerHTML +=
	"<li class='" + pass + "'>" + msg + "</li>";
}


</script>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8"/>
	<!-- Online here: http://code.eligrey.com/testcases/all/isObjectLiteral.html -->
	<title>isObjectLiteral</title>
	<style type="text/css">
	li { background: green; } li.FAIL { background: red; }
	iframe { display: none; }
	</style>
	</head>
	<body>
	<ul id="results"></ul>
	<script type="text/javascript">
	function isObjectLiteral(obj) {
	if (typeof obj !== "object" \|\| obj === null)
	return false;

	var hasOwnProp = Object.prototype.hasOwnProperty,
	ObjProto = obj;

	while (true) // get obj's Object constructor's prototype
	if (Object.getPrototypeOf(ObjProto = Object.getPrototypeOf(ObjProto)) === null)
	break;

	if (Object.getPrototypeOf(obj) !== ObjProto)
	return false

	else if (!Object.getPrototypeOf.isNative) // workaround if non-native Object.getPrototypeOf
	for (var prop in obj)
	if (!hasOwnProp.call(obj, prop) && !hasOwnProp.call(ObjProto, prop)) // inherited elsewhere
	return false;

	return true;
	};


	if (!Object.getPrototypeOf) {
	if (typeof this.__proto__ === "object") {
	Object.getPrototypeOf = function (obj) {
	return obj.__proto__;
	};
	Object.getPrototypeOf.isNative = true;
	} else {
	Object.getPrototypeOf = function (obj) {
	var constructor = obj.constructor,
	oldConstructor;
	if (Object.prototype.hasOwnProperty.call(obj, "constructor")) {
	oldConstructor = constructor;
	if (!(delete obj.constructor)) // reset constructor
	return null; // can't delete obj.constructor, return null
	constructor = obj.constructor; // get real constructor
	obj.constructor = oldConstructor; // restore constructor
	}
	return constructor ? constructor.prototype : null; // needed for IE
	};
	Object.getPrototypeOf.isNative = false;
	}
	} else if (!("isNative" in Object.getPrototypeOf))
	Object.getPrototypeOf.isNative = true;

	// Function serialization is not permitted
	// Does not work across all browsers
	Function.prototype.toString = function(){};

	// The use case that we want to match
	log("{}", {}, true);

	// Instantiated objects shouldn't be matched
	log("new Date", new Date, false);

	var fn = function(){};

	// Makes the function a little more realistic
	// (and harder to detect, incidentally)
	fn.prototype = {someMethod: function(){}};

	// Functions shouldn't be matched
	log("fn", fn, false);

	// Again, instantiated objects shouldn't be matched
	log("new fn", new fn, false);

	var fn2 = function(){};

	fn.prototype.someMethod = function(){};

	log("new fn2", new fn2, false);

	var fn3 = function(){};

	fn3.prototype = {}; // impossible to detect (?) without native Object.getPrototypeOf

	log("new fn3 (only passes with native Object.getPrototypeOf)", new fn3, false);

	log("null", null, false);

	log("undefined", undefined, false);


	/* Note:
	* The restriction against instantiated functions is
	* due to the fact that this method will be used for
	* deep-cloning an object. Instantiated objects will
	* just have their reference copied over, whereas
	* plain objects will need to be completely cloned.
	*/

	var iframe = document.createElement("iframe");
	document.body.appendChild(iframe);

	var doc = iframe.contentDocument \|\| iframe.contentWindow.document;
	doc.open();
	doc.write("<body onload='window.top.iframeDone(Object);'>");
	doc.close();

	function iframeDone(otherObject){
	// Objects from other windows should be matched
	log("new otherObject", new otherObject, true);
	}

	function log(msg, a, b) {
	var pass = isObjectLiteral(a) === b ? "PASS" : "FAIL";

	document.getElementById("results").innerHTML +=
	"<li class='" + pass + "'>" + msg + "</li>";
	}


	</script>
	</body>
	</html>