fetch() doing GET instead of POST on react-native (iOS)

Question

I have the following code in my component:

fetch('https://domain.com/api', {
  method: 'POST',
  headers: {'Accept': 'application/json', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    key: 'value'
  })
}).
  then((response) => {
    console.log('Done', response);
  });

And every time the request is a GET (checked server logs). I thought it was something to do with CORS (but apparently no such thing in react-native) and ATS (but already turned off by default, plus my domain is HTTPS). I've tried from a browser and from a curl and it worked perfectly, so a priori no issue on server configuration. Any idea what's going on here?

I'm using the latest react-native version.

Answer 1

After further digging, it was definitely an issue with the API + fetch. I was missing a slash at the end of the URL and the API issued a 301, that fetch didn't handle correctly. So I don't know if there is something to fix in the fetch function (and underlying mechanisms) but this fixed my issue :)