Prototyp gry - trudności z warunkami.

Potrzebuje pomocy w ulepszeniu gry. Do dyspozycji mam dwa divy jeden powinien "popychać" ten drugi w trakcie ruchu. Zaprezentowany skrypt działa ale ma swoje mankamenty, cały czas mam problem z uściśleniem warunków. Pozwalam sobie na pominięcie pliku html i css, niemniej są tam błędów nie ma.

let rect = document.getElementById('rect');
let rect2 = document.getElementById('rect2');
let position = findPos(rect);
function findPos(obj) {
    var nleft = 0;
    var ntop = 0;
    if (obj.offsetParent) {
        nleft = obj.offsetLeft
        ntop = obj.offsetTop
        while (obj = obj.offsetParent) {
                nleft += obj.offsetLeft
                ntop += obj.offsetTop
        }
    }
    return [nleft,ntop];
}
function changePos() {
    console.log("zółty kwadrat x = " + ((findPos(rect2)[0])) + " y = " + ((findPos(rect2)[1])));
    console.log("czarny kwadrat x = " + ((findPos(rect)[0])) + " y = " + ((findPos(rect)[1])));     
            if(findPos(rect)[0] === findPos(rect2)[0]) {;       
                if(findPos(rect)[1]+100 === findPos(rect2)[1]) {
                    rect2.style.top = (findPos(rect)[0])+100 + "px";
                }
                if(findPos(rect)[1]-100 === findPos(rect2)[1]) {
                    rect2.style.top = (findPos(rect)[0])-100 + "px";
                }
            }
            if(findPos(rect)[1] === findPos(rect2)[1]) {    
                if(findPos(rect)[0]-100 === findPos(rect2)[0]) {
                    rect2.style.left = (findPos(rect)[1])+100 + "px";
                }
                if(findPos(rect)[0]+100 === findPos(rect2)[0]) {
                    rect2.style.left = (findPos(rect)[1])-100 + "px";
                }
            }
}
window.addEventListener('keydown', function(event) {
    switch (event.keyCode) {    
        case 37:
        console.log("Left");
        rect.style.left = (findPos(rect)[0])-20 + "px";
        break;
        case 39:
        console.log("Right");
        rect.style.left = findPos(rect)[0] + "px";
        break;       
        case 38:
        console.log("Up");
        rect.style.top = (findPos(rect)[1])-20 + "px";
        break;                                   
        case 40:
        console.log("Down");
        rect.style.top = findPos(rect)[1] + "px";
        break;
    }
    changePos();
 
}, false);