v mode (ie, locally running <code>npm install</code>), it&#39;ll
run this script as well, so that you can test it easily.</p>
<h2 id="peerdependencies">peerDependencies</h2>
<p>In some cases, you want to express the compatibility of your package with a
host tool or library, while not necessarily doing a <code>require</code> of this host.
This is usually referred to as a <em>plugin</em>. Notably, your module may be exposing
a specific interface, expected and specified by the host documentation.</p>
<p>For ex