I am trying to follow https://blog.mozilla.org/addons/2022/03/17/new-api-for-submitting-and-updating-add-ons/ to upload an addon file. It works fine with cURL but I really want to use Node.js (stuck on 16 at the moment) since I have to build a JWT. I am using the --experimental-fetch flag with node and am trying to avoid adding any more dependencies.

Here’s what I have so far but the endpoint is complaining that the “upload” key is missing from the form data even though I am adding the file stream to the form data using the “upload” key.

const jwt = require('jsonwebtoken');
const fs = require('fs');

var issuedAt = Math.floor(Date.now() / 1000);
var payload = {
  iss: process.env.WEB_EXT_API_KEY,
  jti: Math.random().toString(),
  iat: issuedAt,
  exp: issuedAt + 60,
};

var secret = process.env.WEB_EXT_API_SECRET;  // store this securely.
var token = jwt.sign(payload, secret, {
  algorithm: 'HS256',  // HMAC-SHA256 signing algorithm
});

async function main() {
    const manifest = require('../manifest.json');
    const file_path = `web-ext-artifacts/myaddon-${manifest.version}.zip`
    const fileBuffer = fs.createReadStream(file_path); // should this be something else?

    const form = new FormData();
    form.append('upload', fileBuffer); // Is this wrong?
    form.append('channel', 'listed');
    console.log('formData', form);


    const url = 'https://addons.mozilla.org/api/v5/addons/upload/'
    const req = new Request(url, {
        method: 'POST',
        body: form,
    })
    req.headers.append('Authorization', `JWT ${token}`);
    req.headers.append('Accept', 'application/json');

    fetch(req).then(async (res) => {
        // console.log('response:', res);
        console.log('response.status:', res.status);

        const resData = await res.json();
        console.log('response.body:', resData);

        if (!res.ok) {
            throw new Error(`HTTP error! Status: ${res.status}`);
        }
    })
    .catch(err => {
        console.error(err);
    });
}

main().catch(err => {
    console.log(err)
})

Output when running the above:

formData FormData {
  [Symbol(state)]: [
    { name: 'upload', value: '[object Object]' },
    { name: 'channel', value: 'listed' }
  ]
}
(node:2723925) ExperimentalWarning: Fetch is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
response.status: 400
response.body: [ 'Missing "upload" key in multipart file data.' ]
Error: HTTP error! Status: 400