[question] [howto] How to post a file to Nucleus?

[mcdoolz]

I'm using Atlassian Nucleus and I've been trying to post my electron application release and failing.

I have a local Docker container set up for Nucleus and I can post releases using electron-forge; the files appear, versioned and ready to rock and roll.

I've written a javascript form and I've been attempting to post the release this way as I use electron-packager (electron-forge packages hit just south of a gigabyte while electron-packager prunes to under 300mb).

The form works well enough but I can't seem to post files to Nucleus.

This was my latest iteration:

<form id="release_form">
  <label for="server_address">Enter an address for an update server to post to.<br><sup>This defaults to localhost:3030</sup></label>
  <input id="server_address" type="text" placeholder="http://localhost:3030" />
  <label for="release_package">Select the folder to upload.</label>
  <input id="release_package" type="file" />
  <input id="submit_release" type="submit" />
</form>
<script>
  (function($) {
    const release_package = document.getElementById('release_package');
    const server_address = document.getElementById('server_address');
    const submit_release = document.getElementById('submit_release');

    $('#release_form').on('submit', function(e) {
      e.preventDefault();
      submit_release.disabled = true;
      if (release_package.value) {
        console.log(release_package.value);

        const data = new FormData();
        data.append('platform', 'darwin');
        data.append('arch', 'x64');
        data.append('version', '0.3.0');

        let reader = new FileReader();
        reader.onload = () => {
          data.append(`file`, reader.result);

          const config = {
            host: (server_address.value) ? server_address.value : 'http://localhost:3030',
            appId: '1',
            channelId: 'channel_id',
            token: 'token'
          }

          fetch(`${config.host}/rest/app/${config.appId}/channel/${config.channelId}/upload`, {
            headers: {
              'Authorization': config.token
            },
            method: 'POST',
            body: data,
          }).then((response) => {
            if (response.status !== 200) {
              console.error(`Unexpected response code from Nucleus: ${response.status}`);
            }
            console.log(response);
          }).finally(() => {
            submit_release.disabled = false;
          });
        }

        reader.readAsBinaryString(release_package.files[0]);

      }
    });
  })(jQuery);
</script>

This iteration comes after several other attempts using various approaches all of which were derived from the suggested example in Electron-Forge's NodeJS publishing code.

The above code results in a 500 error. Attempting to use release_package.files[0] directly results in a 400 error.

Any help would be greatly appreciated.

Edit:
Solved the issue; turns out, using Fetch, I wasn't seeing the error being returned by Nucleus, which asked for the version in the file name. The code posted above otherwise works perfectly.