JS Bin // source https://jsbin.com/cegiseq

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>

<pre id='display-panel'></pre>
<script id="jsbin-javascript">
function getRandomInt(min, max) {
  return Math.random() * (max - min) + min;
}

const search = (word, callback) => {
  const results = ['foo', 'bar', 'baz', 'baz2', 'etc', 'etc2'];
  
  const numberOfResults = getRandomInt(1, results.length);
  const randomTimeout = getRandomInt(1, 4);
  
  setTimeout(() => {
    callback(null, results.slice(0, numberOfResults));
  }, randomTimeout);
};

const display = (data) => {
  console.log('display', data);
  const el = document.querySelector('#display-panel');
  const msg = (typeof data === 'string') ? data : data.join(', ');
  
  el.textContent = msg;
};

const displaySearchResults = (error, results) => {
  if (error) {
    display('Search failed, please retry later.');
  } else {
    display(results);
  }
};

const word = 'cats';

// will display random results each time
// uncomment to check
// search(word, displaySearchResults);

// will always display the same results because they are cached
searchWrapper('cats', displaySearchResults);
</script>

const displaySearchResults = (error, results) => {
  if (error) {
    display('Search failed, please retry later.');
  } else {
    display(results);
  }
};

const word = 'cats';

// will display random results each time
// uncomment to check
// search(word, displaySearchResults);

// will always display the same results because they are cached
searchWrapper('cats', displaySearchResults);
</script></body>
</html>