title: angular-cli run command after ng build
body: <p>I am wondering how to extend ng build to run tasks after it has finished.</p>
  <p>At the moment, my end goal is to copy my 'package.json' to the dist folder.</p>
  <p>Something like this if I was using plain npm:</p>
  <pre class="lang-json prettyprint-override"><code>&quot;postbuild&quot;: &quot;cpx ./package.json ./dist/&quot;,
  </code></pre>
  <p>I know in the angular-cli.json I can use &quot;assets&quot; to copy static files, but it does not work for files outside of src. So, I'm wondering if I can do the copy task after ng build completes.</p>