Bootstrap 4 error "Bootstrap dropdown require Popper.js", with Aurelia CLI and Require.js : <p>I'm having trouble configuring Bootstrap 4 beta in an Aurelia CLI app (v0.31.1) with requirejs and using TypeScript. After having tried several config variations I keep on getting the following console error:</p>

<blockquote>
  <p>Uncaught Error: Bootstrap dropdown require Popper.js</p>
</blockquote>

<p>Here are the steps to reproduce. First, install the packages:</p>

<pre><code>$ npm install --save jquery bootstrap@4.0.0-beta popper.js
</code></pre>

<p>Next, I've configured <strong>aurelia.json</strong>:</p>

<pre><code>  "jquery",
  {
    "name": "popper.js",
    "path": "../node_modules/popper.js/dist/umd",
    "main": "popper"
  },
  {
    "name": "bootstrap",
    "path": "../node_modules/bootstrap/dist",
    "main": "js/bootstrap.min",
    "deps": [
      "jquery",
      "popper.js"
    ],
    "exports": "$",
    "resources": [
      "css/bootstrap.css"
    ]
  }
</code></pre>

<p>Notice in the config above that: </p>

<ul>
<li>popper.js is registered before bootstrap</li>
<li>the UMD module is used</li>
<li>popper.js is set as a dependency for bootstrap, next to jquery</li>
</ul>

<p>Finally, in my <strong>app.ts</strong>:</p>

<pre><code>import 'bootstrap';
</code></pre>

<p>With this configuration, building using <code>au build</code> works fine. But upon running, using <code>au run --watch</code> I get the following console errors:</p>

<blockquote>
  <p>Uncaught Error: Bootstrap dropdown require Popper.js (<a href="https://popper.js.org" rel="noreferrer">https://popper.js.org</a>) (defaults.js:19)<br>
  Uncaught Error: Bootstrap dropdown require Popper.js (<a href="https://popper.js.org" rel="noreferrer">https://popper.js.org</a>) (bootstrap.min.js:6)<br>
  ... a bit further on:<br>
  Uncaught TypeError: plugin.load is not a function at Module. (defaults.js:19)</p>
</blockquote>

<p>Unfortunately, the Bootstrap 4 docs only mention <a href="https://getbootstrap.com/docs/4.0/getting-started/webpack/" rel="noreferrer">instructions on webpack</a>. So does a search on both Aurelia's <a href="https://gitter.im/aurelia/Discuss" rel="noreferrer">Gitter.im channel</a> and on StackOverflow. I cannot find samples regarding Aurelia CLI with Require.js. Finally, Google hits shows only examples for embedding the alpha versions (which relied on 'tethering' rather than 'popper').</p>

<p>Similar questions on SO, which have the same error but aren't applicable to my situation:</p>

<ul>
<li><a href="https://stackoverflow.com/questions/45645971/bootstrap-4-beta-importing-popper-js-with-webpack-3-x-throws-popper-is-not-a-con">Bootstrap 4 Beta importing Popper.js with Webpack 3.x throws Popper is not a constructor</a></li>
<li><a href="https://stackoverflow.com/questions/45680644/angular-4-bootstrap-dropdown-require-popper-js">Angular 4 Bootstrap dropdown require Popper.js</a></li>
<li><a href="https://stackoverflow.com/search?q=Bootstrap+dropdown+require+Popper.js">And several more...</a></li>
</ul>

<p>So, my question: how can I configure Bootstrap 4 with Popper.js in an Aurelia CLI app (using Require.js, not Webpack)?</p>

<p>Thanks.</p>
