title: How to test the data-types of number and null in Chai and Postman?
body: <p>I am trying to verify the data-type of a response in my API test using Postman. The returned value can be <strong>integer, float, or null</strong>. 
  How can I do this with Chai and in one statement?</p>
  
  <p>these are my simplified assertions in a Postman test using javascript and Chai.</p>
  
  <pre><code>    pm.expect(23).to.be.a('number'); // PASS
      pm.expect(2.3).to.be.a('number'); // PASS
      pm.expect(23).to.be.oneOf(['number', null]); // FAIL
      pm.expect(2.3).to.be.oneOf(['number', null]); // FAIL
  </code></pre>
  
  <p>I expect all of the assertions to pass. 
  Thanks and I appreciate any comment.</p>