Returns true if obj1 differs in any way from obj2

testDiff.js

// Returns true if obj1 differs in any way from obj2
function testDiff(obj1, obj2) {
	if (obj1 === null) return obj1 !== obj2;
	const stack = [{ obj1: obj1, obj2: obj2 }];
	const seen = new Map();
	seen.set(obj1, stack[0]);
	_objects: while (stack.length !== 0) {
		const objects = stack.pop();
		if (Array.isArray(objects.obj1) !== Array.isArray(objects.obj2)) return true;
		const props1 = Object.keys(objects.obj1);
		const props2 = Object.keys(objects.obj2);
		if (props1.length === 0 && props2.length === 0) continue;
		if (props1.length !== props2.length) return true;
		if (!props1.every(value => props2.includes(value))) return true;
		if (!props2.every(value => props1.includes(value))) return true;
		_props: for (var loc = 0; loc < props1.length; loc++) {
			const prop = props1[loc];
			const value1 = objects.obj1[prop];
			const value2 = objects.obj2[prop];
			if ((typeof value1) !== (typeof value2)) return true;
			if ((typeof value1) === "object") {
				if (value1 === null) {
					if (obj1 !== obj2) return true;
					continue _props;
				}
				if (seen.has(value1)) continue _props;
				stack.push({ obj1: value1, obj2: value2 });
				seen.set(value1, objects);
				continue _props;
			}
			if (Number.isNaN(value1) !== Number.isNaN(value2)) return true;
			if (value1 !== value2) return true;
		}
	}
	return false;
}