401 not handled on iOS

I am developing an Apache Cordova app and use your polyfill because iOS does not support the fetch API at the moment. Unfortunately this polyfill does not work when the server throws an http 401.

For example I make a fetch POST request like this one

fetch(address, {
  method: 'POST',
  headers: {
    'Accept': 'application/json',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    'my': 'body'
  }),
})
.then(response => {
  if (response.ok) {
    return response.json();
  }
  throw new Error(`HTTP ${response.status}: ${response.statusText}`);
})

On Android I can see the thrown error, on iOS nothing happens. The code block in .then is never called. It seems that fetch swallowed everything and does not resolve the promise.

[screendriver]

No, it’s not working. The AJAX request is never returned. In Safari developer tools you can see that the request is never ending. Please reopen this issue.

[screendriver]

Hi @zooldk,

as I mentioned before: it is not a bug in this polyfill. It’s a general bug on iOS. You can’t handle http 401 errors from JavaScript on iOS. The only thing you can do is to remove the WWW-Authenticate server response header if you have access to the server implementation. Then it should work, but that is a little bit hacky.