FA-75965 / Chat ordering and read receipts / Member archive

Fold out-of-order delivery events into a recipient status: no regression · case 05

A late "sent" event downgrades a message that was already read.

Member previewVariant 5 · 3 implementations · 9 checks per implementation

Case contract

events are [seq, kind] with kind in queued, sent, delivered, read, failed, retry, processed in (seq, kind) order. Ranks queued<sent<delivered<read and status never regresses. failed only applies while queued or sent; retry moves failed back to queued; after a failure only delivered or read evidence (not a stale sent) replaces it. Result {status, history} where history lists every status change starting at queued.

Why this case matters

Per-recipient ticks are assembled from events that arrive out of order across transports.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
late sent after read	`{"history": ["queued", "read", "sent", "delivered"], "status": "delivered"}`	`{"history": ["queued", "read"], "status": "read"}`	Failed

MEMBER ARCHIVE

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