title: Why am I getting "Error: Resolution method is overspecified"?
body: <p>After the upgrade, Mocha can not even run a simple test here is the code</p>
  
  <pre><code>const assert = require('assert');
  
  it('should complete this test', function (done) {
    return new Promise(function (resolve) {
      assert.ok(true);
      resolve();
     })
    .then(done);
  });
  </code></pre>
  
  <p>I took this code from <a href="https://github.com/mochajs/mocha/blob/master/CHANGELOG.md#boom-breaking-changes" rel="noreferrer">here</a></p>
  
  <p>I understood that it now throws an exception <code>Error: Resolution method is overspecified. Specify a callback * or * return a Promise; not both.</code></p>
  
  <p>But how to make it work? I did not understand. I have</p>
  
  <pre><code>node -v 6.9.4
  
  mocha -v 3.2.0
  </code></pre>
  
  <p><strong>How to run this code are now in a new and correct format?</strong></p>