foo.js

const greet = ({ name = 'Me' }) => console.log(`Hi ${ name }`);

const repeat = (name, count = 0) => {
  if (count) {
    setTimeout(() => greet({ name }), 1000 * count); 
    repeat(`${ name }.`, count - 1);
  }
};

repeat('Boris', 10);

second.js

const user = {
  name: 'Boris',
  images: {
    thumb: 'image'
  }
};

function getImage(user, type) {
  var images = user && user.images || {};
  var thumb = images && images[type] || 'none';

  console.log(thumb);
}

getImage(user, 'thumb');
getImage(user, 'full');
getImage({ }, 'thumb');
getImage({ images: {} }, 'thumb');