title: How to resolve typescript error for topojson package?
body: <p>Please forgive the naive question; I'm new to Typescript. In javascript, I can use <a href="https://github.com/topojson/topojson-client/blob/master/README.md#mesh" rel="nofollow noreferrer">topojson.mesh</a> to create a mesh object like this:</p>
  
  <pre><code>import us from "./counties-albers-10m.json"
  topojson.mesh(us, us.objects.states, (a, b) =&gt; a !== b))
  </code></pre>
  
  <p>When I try to do this in Typescript, I get this warning:</p>
  
  <pre><code>Types of property 'type' are incompatible. Type 'string' is not assignable to type "Topology" TS2345
  </code></pre>
  
  <p>I have <code>@types/topojson</code> installed as well. Can anyone help me debug this? I do not understand enough about typescript to understand what the problem is.</p>
  
  <p>More broadly, how does one debug errors like this? I find all sorts of type issues with 3rd party packages and do not know how to assign my javascript objects the right type in many cases. Thanks for the help.</p>