title: chai-as-promised types conflict with chai
body: <p>I have unit tests that depend on <code>chai</code> and <code>chai-as-promised</code> (a library that extends Chai so you can easily test promises)</p>
  
  <p>This assertion:</p>
  
  <pre><code>return expect(myPromise).to.eventually.equal(true)
  </code></pre>
  
  <p>gives me compile error</p>
  
  <pre><code>error TS2300: Duplicate identifier AssertionError
  </code></pre>
  
  <p>when I have both <code>@types/chai</code> and <code>@types/chai-as-promised</code> installed.</p>
  
  <p>When I uninstall <code>@types/chai-as-promised</code> I get error</p>
  
  <pre><code>error TS2339: Property 'eventually' does not exist on type 'Assertion'.
  </code></pre>
  
  <p>So obviously types are necessary</p>
  
  <p>What is going wrong here? Is <code>chai-as-promised</code> extending <code>chai</code> poorly? Should I create my own types for it?</p>