title: Fetch api issue with DELETE - changes to OPTIONS even when cors is good
body: <p>Using fetch api in the client browser, I am not having issues with GET or POST, but I am having issues with fetch and DELETE. Its seems to change the DELETE request method to OPTIONS. </p>
  
  <p>Most of the research shows to be a cors issues, but with me I have the cors issues covered. </p>
  
  <p>I am not sure if this is a <a href="https://fetch.spec.whatwg.org/#methods" rel="noreferrer">valid fetch spec api link</a> but it shows: </p>
  
  <blockquote>
    <p>A CORS-safe listed method is a method that is <code>GET</code>, <code>HEAD</code>, or <code>POST</code>.</p>
  </blockquote>
  
  <p>I am not sure if this means I can not use DELETE on fetch with cors and this is why I am having issues? </p>
  
  <p>browser code: </p>
  
  <pre><code>var request =
            new Request(url, {
              credentials: 'include',
              mode: 'cors',
              method: 'DELETE'
            });
  
          return fetch(request)
            .then(this.fetchError.bind(this))
            .then(this.json)
            .then((response)=&gt; {
              this.set(`uploadState.${index}.value`, false);
            })
            .catch((e) =&gt; {
              console.log(e);
            });
        },
  </code></pre>
  
  <hr>
  
  <p>chrome network tab:</p>
  
  <pre><code>Request URL:http://72.12.4.3:9000/api/v1/listings/3/47/image-3-47-1492565415145.jpeg
  Request Method:OPTIONS
  Status Code:401 Unauthorized
  Remote Address:72.12.4.3:9000
  
  Response Headers
  view source
  Access-Control-Allow-Credentials:true
  Access-Control-Allow-Headers:true
  Access-Control-Allow-Methods:POST, GET, OPTIONS, DELETE
  Access-Control-Allow-Origin:http://72.12.4.3:8000
  Connection:keep-alive
  Content-Length:25
  Content-Type:application/json; charset=utf-8
  Date:Wed, 19 Apr 2017 01:36:07 GMT
  ETag:W/"19-9NCRiMyz+z1Bt6fGQfcxA"
  X-Powered-By:Express
  
  Request Headers
  view source
  Accept:*/*
  Accept-Encoding:gzip, deflate, sdch
  Accept-Language:en-US,en;q=0.8
  Access-Control-Request-Headers:
  Access-Control-Request-Method:DELETE
  Cache-Control:no-cache
  Connection:keep-alive
  Host:72.12.4.3:9000
  If-None-Match:W/"19-9NCRiMyz+z1Bt6fGQfcxA"
  Origin:http://72.12.4.3:8000
  Pragma:no-cache
  Referer:http://72.12.4.3:8000/
  User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36
  </code></pre>