Weird issue(s) with fetch from endpoint and multipart file content

Describe the bug

After NPM update have some issues with uploading multipart form content including a file. This used to work fine.

Now get MultipartParser.end(): stream ended unexpectedly when trying the same code in a js endpoint.

Also after this error repeated actions seem not to forward the multipart form data

Reproduction

Just do form submit with multipart content to a js endpoint.

Try to forward that to another server like https://kit.svelte.dev/docs/routing#endpoints-body-parsing mentioned here.

` export async function post({ url,request, event,locals}) { const data= await request.formData();

const nftsReq = await fetch( 'someurl', {
    method: 'POST',
    body: data
})

`

Happens with each first upload. The forwarded request seems without data. Seems like the fetch behavior changed?

Logs

MultipartParser.end(): stream ended unexpectedly
Error: MultipartParser.end(): stream ended unexpectedly
    at MultipartParser.end (file:///C:/Users/mvanh/source/repos/DeSo/nftz/nftz-front/node_modules/@sveltejs/kit/dist/chunks/multipart-parser.js:326:10)
    at toFormData (file:///C:/Users/mvanh/source/repos/DeSo/nftz/nftz-front/node_modules/@sveltejs/kit/dist/chunks/multipart-parser.js:440:9)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async post (C:\Users\mvanh\source\repos\DeSo\nftz\nftz-front\src\routes\api\account\uploadimage.js:4:17)
    at async render_endpoint (file:///C:/Users/mvanh/source/repos/DeSo/nftz/nftz-front/.svelte-kit/runtime/server/index.js:269:19)
    at async resolve (file:///C:/Users/mvanh/source/repos/DeSo/nftz/nftz-front/.svelte-kit/runtime/server/index.js:3345:11)
    at async Object.handle (/C:\Users\mvanh\source\repos\DeSo\nftz\nftz-front\src\hooks:72:12)
    at async respond (file:///C:/Users/mvanh/source/repos/DeSo/nftz/nftz-front/.svelte-kit/runtime/server/index.js:3290:20)
    at async file:///C:/Users/mvanh/source/repos/DeSo/nftz/nftz-front/node_modules/@sveltejs/kit/dist/vite.js:2324:22

System Info

Windows, Vercel, latest npm update version

Severity

serious, but I can work around it

Additional Information

No response

[x-GF-x]

I am still having this issue. 1.0.0-next.391. Trying to post a PDF and the formData being sent in the body is coming through empty. Was working before switch to POST

[DePasqualeOrg]

It’s working now with the latest update.