title: Default function parameters doesn't work as I expected
body: <p>I have this function:</p>
  
  <pre class="lang-js prettyprint-override"><code>const func = (a, b, options = { opt1: false, opt2: false, opt3: false }) =&gt; {
   // do something
   console.log(options); // { opt1: false, opt2: false, opt3: false }
  }
  </code></pre>
  
  <p>so when I call it without any params, I'm getting this</p>
  
  <pre class="lang-js prettyprint-override"><code>func('a', 'b', { opt3: true });
  // { opt3: true }
  </code></pre>
  
  <p>instead of expected:</p>
  
  <pre class="lang-js prettyprint-override"><code>// { opt1: false, opt2: false, opt3: true }
  </code></pre>