[ytkimirti]

upload() and the upload hooks now throw invalid_input (400) naming Bucket.put when XMLHttpRequest is missing, before any route call, instead of failing after begin as a 503 request_failed.
A headers() throw or non-JSON input is now a 400 and other bugs a 500 instead of 503; any 2xx for end counts as accepted, so a cut-off or malformed answer is a 502 that retry() and resume never re-send.
Docs: upstash/docs#953

[CahidArda]

Re-sending a cut-off end can delete an accepted upload (high).

routeCall now re-sends a call whose 2xx body was cut off (src/browser/task.ts:583-588). A 2xx for end means onUploadComplete has already returned, and end isn't idempotent on the server:

• Single PUT: onUploadComplete runs again. If it throws (for example a duplicate key), discard() deletes the object the first call accepted.
• Multipart: onUploadComplete runs again, so the app gets a duplicate row.

Fix: don't re-send end after a 2xx; throw a "completed, response lost" error instead. Main's existing retries of end on 5xx and network errors have the same problem, so end should also be made idempotent on the server.

Release notes: upload() now throws synchronously outside a browser, and headers() throws now return 400 (other non-BlobErrors 500) instead of 503.