 of the function</p>
<p>In the refactored version, it&#39;s trivial to test whether <code>getFirstTen</code> has any off-by-one errors, or whether we forgot to add a space between the first and last names in <code>getUserName</code>.</p>
<hr>
<h3 id="promise-absorption"><a href="#promise-absorption">Promise absorption</a></h3>
<p>Promises absorb other promises. Basically, this means you can never receive a Promise as an argument to <code>onFulfilled</code> or <code>onRejected</code> callbacks for <code>then