title: How do you make a form input field that grows upwards like in Facebook's messenger.com?
body: <p>In Facebook's messenger.com, the input field where you type your message in grows vertically upwards once the message you're typing in wraps to the next line or if you insert a carriage return. I'm wondering if this is a default behavior of an HTML input element or if it is some JavaScript magic to make this happen. Does anyone know how this is done?</p>
  
  <p><a href="https://i.stack.imgur.com/sW5AP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sW5AP.png" alt="Messenger input field"></a></p>