Partial upload retries may count toward limit without deduplication

Direct answer

A network interruption after only part of the request body has been sent is a client-side transport failure, not a completed upload. Under standard HTTP semantics, the uploader should count that interrupted attempt as one retry attempt and retry only if attempts remain. Because the server never receives a complete payload, it cannot store coverage or apply a deduplication key to that attempt, so a mid-request connection close by itself should not create duplicate coverage entries.

Assumptions and uncertainty

This answer relies on general HTTP behavior, not on current Codecov documentation. The exact retry flag, default limit, client idempotency token, and server deduplication key vary by Codecov uploader product and version. A partial payload could be partially accepted only if a proxy buffers and replays the request or the server processes streaming input before validation; those are not the expected behavior for a standard upload endpoint.

Likely explanation versus confirmed facts

Scenario	Likely behavior	Confirmed for Codecov?
Connection closed after partial body send	Counts as one attempt against the retry limit; retry if attempts remain	No
Server receives incomplete payload	Rejected before deduplication; no coverage stored	No
Duplicate coverage after retries	Suggests deduplication did not apply or the same context was submitted twice; not explained by a partial send alone	No

Verification steps

1. Identify the Codecov uploader product and version, and the configured retry limit. This detail changes whether you should adjust retry settings.
2. Enable verbose or debug logging for the upload and inspect logs from a failed CI run.
3. Confirm that the partial attempt produced a client error or non-success status and that no upload record appears for that attempt in Codecov.
4. Compare Codecov results for the same commit, build, branch, flags, and upload name before and after the interrupted attempt. Duplicate entries or coverage totals above one expected report indicate inconsistency.
5. If available, run in dry-run mode first to confirm the intended payload and upload context without sending coverage data.

Missing diagnostic detail

Which Codecov uploader product and version are you using, and what is the configured retry limit? Provide that before changing retry settings, because behavior differs across uploaders and versions.

Bottom line

Treat a connection closed after a partial send as one consumed retry attempt, not as a successful or deduplicated upload. Expect the server to reject the incomplete body before deduplication. Verify with uploader logs and Codecov upload records; do not infer consistency from client behavior alone, especially if proxies may buffer or replay requests.