upload progress return response.json()?

[borm]

Hi, i have readed
whatwg/fetch#21
#202
#290
#379

And this issue copy whatwg/fetch#389

How get response json from server after progress upload

function consume(response, total=0) {
  var reader = response.body.getReader()
  return pump()
  function pump() {
    return reader.read().then(({done, value}) => {
      if (done) {
        return response
      }
      total += value.byteLength
      log(`received ${value.byteLength} bytes (${total} bytes in total)`)
      return pump()
    })
  }
}

fetch("/music/pk/altes-kamuffel.flac", {method: 'POST', body: MYFormData})
  .then(response => consume(response))
  .then(response => return response.json() // "return Already read" )
  .then((resultFromServer) => log(resultFromServer.file)) 
  .catch(e => log("something went wrong: " + e))

[dgraham]

In this example, you're uploading a form to an audio URL, then reading a streaming response body from the server, then consuming the response again as a JSON document. An HTTP response body may only be consumed a single time.

This fetch polyfill does not implement response body streaming, so you'll want to use Chrome for testing that.