title: Property does not exists on type '{}' using Promises
body: <p>I am accessing a property of an object returned from a resolved promise. </p>
  
  <pre><code>return new Promise((resolve) =&gt; {
      // Get result
      resolve(result)
  }).then(r =&gt; console.log(r.id))
  </code></pre>
  
  <p>Typescript compiles the code and the code works but my IDE is complaining about <code>r.id</code></p>
  
  <blockquote>
    <p>[ts] Property 'id' does not exist on type '{}'.</p>
  </blockquote>
  
  <p>What is the 'TypeScript' method of dealing with this? <a href="https://stackoverflow.com/questions/39709205/property-does-not-exist-on-type-in-angular2">This question</a> seems to have the same issue but I cannot understand the given solutions. <a href="https://stackoverflow.com/a/49467180/817379">This answer</a> talks about using interfaces but im not sure how I would apply that to the <code>then()</code> function of a <code>Promise</code></p>