renderDashboard issued three parseAllSessions calls (scan range, plan window,
durable headline). They often share a START and differ only in where they end —
end-of-day vs each caller's own `new Date()` — which the exact-key memo cannot
match, so a warm render paid for the discovery sweep, the cache read and the
parse two or three times over.
withSinglePassParse lets a caller declare the widest range it will ask for. A
later request that is a PURE NARROWING of it is served by slicing that parse
instead of running the pipeline again. Pure narrowing is deliberately strict:
same start, an end that is inside, and the same month shard scope. Both extra
conditions are load-bearing, because a parse's file set is a function of its
range:
- a changed file with `mtimeMs < range.start` is skipped without being parsed,
so an earlier start reads files a later start never sees;
- loadCache reads only the shards monthScopeForRange selects;
- either way the extra files seed seenKeys/seenMsgIds BEFORE the range slice,
and a seeded key suppresses the matching in-range turn in a provider parsed
later — usage the narrower parse would have counted.
Holding start and month scope equal makes both parses see an identical file set,
leaving the range slice as the only difference — the same trade burstReuse
already makes for the mirror-image case (same start, later end).
Independently, correlateCrossProviderPrSessions ran two O(n*m) scans: a
`sessions.filter` per subagent child (now a one-shot agentId index) and a full
`launches.filter` per candidate (now a sorted array plus a windowed scan). Both
preserve the exact match set; launch order was never observable because the
matches collapse into a Map keyed by the sorted ref list.
Warm, 21k-file corpus, isolated cache, median of 5 interleaved:
today 5.12s -> 3.81s (1.34x) 3 parses -> 2
month 5.46s -> 3.41s (1.60x) 2 parses -> 1
today --format json 4.11s -> 3.49s (1.18x, correlation hoist only)
vitest.config gains an explicit exclude so a .claude worktree's stale tests/
copy stops being swept into the run.
Refs #1106
The 5s default failed three unrelated real-I/O tests on the CI Node-22 runner
in two days (dashboard optimize scan, codex resume differential, OTel DB
prune) purely from runner load. Hung tests still fail at 30s.
* fix: fix and improve test isolation and collision with environment
* docs: remove unnecessary comment
* test(env-isolation): clear CODEBURN_FORCE_MACOS_MAJOR and pin TZ
Two env vars read in src/ were not isolated: CODEBURN_FORCE_MACOS_MAJOR
(now cleared so it cannot leak between tests) and TZ (now pinned to UTC,
since clearing it falls back to the OS zone and would shift date buckets
versus a clean CI runner).
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Co-authored-by: AgentSeal <hello@agentseal.org>
