title: How do you know if a JavaScript library you are using will break your code after an upgrade?
body: <p>So, you are using a bunch of javascript libraries in a website. Your javascript code calls the several APIs, but every once in a while after an upgrade, one of the API changes, and your code breaks, without you knowing it.</p>
  
  <p>How do you prevent this from happening?</p>
  
  <p>I'm mostly interested in javascript, but any answer regarding dynamically typed languages would be valuable.</p>