fix(dispatch): sort local dispatch candidates for stable output

18e5753→main·

alishakawaguchi·yesterday·2 files·+43 added/-0 removed

Trail review: the trailer fallback pass ranges over a map (reachableCheckpointIDs), and Go randomizes map iteration order, so candidates were appended in a non-deterministic order. Nothing downstream re-sorts, so re-running dispatch --local over the same window could emit bullets in a different order — and thus a different LLM-authored summary — each time.

Sort the collected candidates most-recent-first (tiebreak by checkpoint ID) before returning, so dispatch output is stable across runs.

Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com Claude-Session: https://claude.ai/code/session_01Wi6WfsYgVrWDrZXpu62u8u

Changes

2

• cmd/entire/cli/dispatch

• Mmode_local.go+16

• Mmode_local_test.go+27

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272 unmodified lines

seen[idStr] = struct{}{}
}

// The second pass ranges over a map (randomized iteration order), so sort
// before returning to keep bullet order — and therefore the LLM-authored
// summary — stable across runs. Newest first, with the checkpoint ID as a
// deterministic tiebreak for equal timestamps.
sortCandidatesByRecency(candidates)
return candidates, nil
}

// sortCandidatesByRecency orders candidates most-recent-first by CreatedAt,
// breaking ties by checkpoint ID so the order is fully deterministic.
func sortCandidatesByRecency(candidates []candidate) {
    sort.SliceStable(candidates, func(i, j int) bool {
        if !candidates[i].CreatedAt.Equal(candidates[j].CreatedAt) {
            return candidates[i].CreatedAt.After(candidates[j].CreatedAt)
        }
        return candidates[i].CheckpointID < candidates[j].CheckpointID
    })
}

// readLocalSummaryTitle returns the latest session's outcome (falling back to
// its intent) for use as a bullet title, or "" when no session summary is
// available.

Mcmd/entire/cli/dispatch/mode_local.go+16

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879 unmodified lines

}
}

// TestSortCandidatesByRecency covers the trail-review finding: because the
// trailer fallback pass ranges over a map, candidates must be sorted before
// returning so dispatch output is stable across runs. Newest first, ties broken
// by checkpoint ID.
func TestSortCandidatesByRecency(t *testing.T) {

t.Parallel()
    base := time.Date(2026, 4, 1, 0, 0, 0, 0, time.UTC)
    candidates := []candidate{
        {CheckpointID: "ccc", CreatedAt: base},
        {CheckpointID: "aaa", CreatedAt: base.Add(2 * time.Hour)},
        {CheckpointID: "bbb", CreatedAt: base}, // same time as ccc → tiebreak by ID
        {CheckpointID: "zzz", CreatedAt: base.Add(time.Hour)},
    }
sortCandidatesByRecency(candidates)

got := make([]string, len(candidates))
    for i, c := range candidates {
        got[i] = c.CheckpointID
    }
    want := []string{"aaa", "zzz", "bbb", "ccc"} // newest first; bbb < ccc for the tie
    for i := range want {
        if got[i] != want[i] {
            t.Fatalf("sortCandidatesByRecency order = %v, want %v", got, want)
        }
    }
}

func TestLoadCommitSubjectsByCheckpoint_UsesSingleWindowedLogScan(t *testing.T) {
    tmpDir := t.TempDir()
    argsFile := filepath.Join(tmpDir, "git-args.txt")