Takes an element and uses the first image found to replicate the behaviour of background-size: cover
from CSS.
The advantage of this method is that you get all the semantics/accessibility of an image present within the mark-up.
<div data-cover-image>
<img src="http://example.com/cat.jpg"/>
</div>
<script src="https://unpkg.com/coverimage/dist/coverimage.js"></script>
Please do.