fix: stable secondary sort for equal-timestamp session fallback#60
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When two active sessions have byte-identical `last_updated`, `last_entry`, and `created` fields, the most-recent-active fallback in `findActiveSessionForBranch` previously resolved ties via `readdirSync` collection order, which is filesystem- and platform-dependent. Add an alphabetical `filePath` tiebreaker so the comparator is fully deterministic. Session filenames already encode their creation timestamp (`YYYYMMDD-HHMMSS-…md`), so the secondary key still favors recency in the realistic case while removing the non-determinism.
…path) Codex review on PR #60 caught that `pickCandidate` — the sorter shared by the direct branch-match path in `findActiveSessionForBranch` — had the same non-determinism bug as the no-match most-recent-active fallback: candidates with identical effective timestamps (`last_updated` || `last_entry`) ordered by `readdirSync` collection order, which is filesystem-/platform-dependent. - Add `filePath.localeCompare` as the tertiary key in `pickCandidate`, after status priority and effective timestamp. - Tighten the most-recent-active comparator comment to match actual behavior (single effective timestamp with documented fallbacks, not "every timestamp field"). - Add a branch-match tie test mirroring the existing no-match tie test: asserts repeated calls return the alphabetically-first session.
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May 31, 2026
Release v2.0.0-dev.49 covering the deterministic session-fallback tiebreaker fix from PR #60.
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Summary
Follow-up from Codex review on PR #55 (SPEC-042 Track B). The most-recent-active branch-fallback comparator in `findActiveSessionForBranch` used `last_updated || last_entry || created || "0"` with `localeCompare`, then picked index 0. When two active sessions had byte-identical values for all three timestamp fields, the result depended on `readdirSync` collection order — filesystem-dependent and non-deterministic across platforms.
Fix
Add an alphabetical `filePath` tiebreaker to the comparator. Session filenames already encode their creation timestamp (`YYYYMMDD-HHMMSS-…md`), so the secondary key still favors recency in the realistic case while removing the non-determinism.
8-line source change in `cli/lib/session/find.ts`. The SQLite refactor (`994f1740`) did not touch this file; `findActiveSessionForBranch` remains actively imported by `cli/commands/session.ts` and exercised by the e2e session-routing tests.
Test plan
Out of scope