<p dir="auto">Apologies if this is mentioned elsewhere, but I couldn't find an issue/PR that mentions it.</p>
<p dir="auto">The <a href="https://developer.mozilla.org/en/docs/Web/API/Fetch_API" rel="nofollow">Fetch API</a> is still experimental, but I assume its definitions will make their way into TypeScript core at some point?</p>
<p dir="auto">for exemple :</p>
<p dir="auto">module mymodule {</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="export class myclass extends anotherclass {"><pre class="notranslate"><code class="notranslate">export class myclass extends anotherclass {
</code></pre></div>
<p dir="auto">should throw a warning because another class is not referenced as this in the header :</p>
<p dir="auto"><code class="notranslate">/// &lt;reference path="./anotherclass.ts" /&gt;</code></p>
<p dir="auto">this cause in error in code, because extends class is not includes in base class at runtime :</p>
<p dir="auto"><code class="notranslate">Uncaught TypeError: Cannot read property 'prototype' of undefined</code></p>