Query Collection held-result error recency#

Reviewed PR head before this correction: a4a8ba8d0c045dcad23f97d3b98dc7298281f1db. Reviewed semantic correction: 8bd3fc35. Primary owner: packages/query-db-collection/tests/ownership-lifecycle.oracle.test.ts.

The public lastError and errorCount contract retains a completed failure until a later successful result applies. The added two-cell history starts with one failed Query fetch, then holds a successful retry at a mocked persisted baseline scan. A second refetch fails before the held success applies. At the checkpoint after releasing the scan, the later failure must remain visible and the count must be two. One cell uses clearError() and distinct Error objects; the other uses refetch() and repeats the same Error object in one clock tick. The expected state follows the order of completed failures and successful applications, without reading production error timestamps or revisions.

On the uncorrected PR head, both cells failed: the first observed lastError === undefined after the older application, and the second observed errorCount === 1 after two terminal failures. The correction guards error clearing with a revision captured when application begins and distinguishes terminal Query failures using Query Core's per-Query errorUpdateCount. It retains the older successful rows when they apply; it only prevents that application from clearing an error recorded later.

The review's exact mutation-held sequence was also run on the uncorrected PR head. It did not erase the newer error; that path published the earlier rows after the handler settled while preserving lastError and errorCount. The persisted path is the confirmed counterexample. The persisted scan is a controlled callback, not native SQLite execution. Native persistence, concurrent retries for multiple tracked Queries, mutation-handler fetch settlement, and deferred result application remain separate coverage cells in the Query DB ownership row of oracle-coverage.md.

Verification at 8bd3fc35: 532/532 Query DB package tests passed across 15 files; Query DB source typecheck passed; changed-file ESLint had zero errors and four warnings already present outside the edited lines; Prettier and Git diff checks passed. The new persisted cases alone passed 2/2 on the PR branch.

Production weight for this correction is 31 added and 17 removed lines, net +14 relative to the prior PR head. The complete PR production diff is 46 added and 24 removed lines, net +22 relative to origin/main. The added state separates genuinely new terminal failures from observer re-notification and fences an older asynchronous application; it does not add retry or recovery machinery. The oracle adds 91 lines, counted separately.