title: Only copy newer files with CopyWebpackPlugin
body: <p>I'm copying lots of files using the <code>CopyWebpackPlugin</code>, and I want them to be copied only if the files at the destination are older. The same as was common in grunt / gulp.</p>
  <pre class="lang-js prettyprint-override"><code>new CopyWebpackPlugin({
    patterns: [
      { from: &quot;./node_modules/jquery/dist/jquery.min.js&quot;, to: &quot;./libs/&quot; },
    ],
  }),
  </code></pre>
  <p>But the output always shows:</p>
  <blockquote>
  <p>asset libs/jquery.min.js 87.4 KiB [compared for emit] [from: node_modules/jquery/dist/jquery.min.js] [copied]</p>
  </blockquote>
  <p>which implies that it copies it each time.</p>
  <p>How do I make it copy only if the destination is missing or the source is newer?</p>