title: dynamic import json file
body: <p>I used to load a json file like this:</p>
  
  <pre><code>import faq from './faq.json'
  
  interface FAQ {
     title: string
     body: string
  }
  
  interface SiteConfig {
      title: string
      faqs: FAQ[]
  }
  
  sites: {[key: string]: SiteConfig} = {
      siteA: {
          title: 'xx',
          faqs: faq
      }
  }
  </code></pre>
  
  <p>Now I want to use dynamic imports:</p>
  
  <pre><code>interface FAQ {
     title: string
     body: string
  }
  
  interface SiteConfig {
      title: string
      faqs: () =&gt; FAQ[]
  }
  
  sites: {[key: string]: SiteConfig} = {
      siteA: {
          title: 'xx',
          faqs: (): Promise&lt;FAQ[]&gt; =&gt; import('./faq.json')
      }
  }
  </code></pre>
  
  <p>fails with: </p>
  
  <pre><code>Type 'Promise&lt;typeof "*.json"&gt;' is not assignable to type 'Promise&lt;FAQ[]&gt;'.
  </code></pre>