title: Using PIXI.JS a dependency in a ES6 TypeScript API
body: <p>I'm creating an TypeScript Graphics API and would like Rollup to bundle in Pixi.js. I have pixi.js installed as a npm package and am referencing it from my .ts file as such:</p>
  <pre class="lang-js prettyprint-override"><code>import * as PIXI from 'pixi.js'
  </code></pre>
  <p>Rollup (with the TypeScript plugin then warn me):</p>
  <pre><code>(!) Unresolved dependencies
  https://rollupjs.org/guide/en/#warning-treating-module-as-external-dependency
  pixi.js (imported by src/lib/DropJoystick.ts)
  </code></pre>
  <p>and my browser reports an error:</p>
  <pre><code>Uncaught TypeError: Error resolving module specifier “pixi.js”. Relative module specifiers must start with “./”, “../” or “/”.
  </code></pre>
  <p>It's clear to me that Rollup is clearly not bundling PIXI with my TypeScript API in that the browser is now looking for the mode module name (&quot;pixi.js&quot;).</p>
  <p>How do I go about ensuring that RollUp / TypeScript bundle Pixi?</p>