Safer QuerySelector

qs.js

function qs(selector, callback, context) {
  if(callback === undefined) return;
  context = context || document;
  const result = context.querySelector(selector);
  if(result) {
    return callback(result);
  }
}

qs('.some .selector', (safeElement) => {
  // operate on safeElement
  // callback will not be called if `querySelector` returns null
});