fix(quest): stable secondary sort for latest-brief reads (#23) (#75)

SAY-5 · web-flow · commit 53669210235a · 2026-05-06T07:52:27.000-07:00
Signed-off-by: SAY-5 &lt;say.apm35@gmail.com&gt;
diff --git a/internal/quest/brief.go b/internal/quest/brief.go
@@ -68,7 +68,7 @@ func LastBriefAt(ctx context.Context, db *sql.DB, projectID string) (time.Time,
 	qerr := db.QueryRowContext(ctx,
 		`SELECT created_at FROM task_notes
 		 WHERE project_id = ? AND task_id = ? AND note LIKE '[brief]%'
-		 ORDER BY created_at DESC LIMIT 1`,
+		 ORDER BY created_at DESC, id DESC LIMIT 1`,
 		projectID, briefTaskID,
 	).Scan(&createdAt)
 	if qerr != nil {
@@ -95,7 +95,7 @@ func LastBrief(ctx context.Context, db *sql.DB, projectID string) (agentID, text
 	qerr := db.QueryRowContext(ctx,
 		`SELECT agent_id, note, created_at FROM task_notes
 		 WHERE project_id = ? AND task_id = ? AND note LIKE '[brief]%'
-		 ORDER BY created_at DESC LIMIT 1`,
+		 ORDER BY created_at DESC, id DESC LIMIT 1`,
 		projectID, briefTaskID,
 	).Scan(&agent, &note, &createdAt)
 	if qerr != nil {
diff --git a/internal/quest/brief_stable_order_test.go b/internal/quest/brief_stable_order_test.go
@@ -0,0 +1,89 @@
+package quest
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+)
+
+// Regression for #23: "latest brief" reads were non-deterministic when
+// two task_notes rows shared the same created_at string. The
+// LastBrief / LastBriefAt queries used `ORDER BY created_at DESC LIMIT
+// 1` only, so SQLite was free to return either tied row. Adding `id
+// DESC` as a secondary sort key makes the highest-id (latest-inserted)
+// row the unambiguous winner across runs.
+//
+// The test seeds five briefs with byte-identical RFC3339Nano
+// timestamps, then reads the latest brief sameSecondBriefIterations
+// times and asserts every read returns the same row (the one with the
+// highest auto-increment id) — i.e. the most recently inserted brief.
+
+const sameSecondBriefIterations = 10
+
+func TestLastBrief_StableOrderForSameTimestampInserts(t *testing.T) {
+	db, pid := newTestDB(t)
+	ctx := context.Background()
+
+	ts := time.Date(2026, 5, 5, 12, 0, 0, 0, time.UTC).Format(time.RFC3339Nano)
+	const n = 5
+	for i := 0; i < n; i++ {
+		text := fmt.Sprintf("brief-%02d", i)
+		if _, err := db.ExecContext(ctx,
+			`INSERT INTO task_notes (project_id, task_id, agent_id, note, created_at)
+			 VALUES (?, ?, ?, ?, ?)`,
+			pid, briefTaskID, "agent", briefPrefix+text, ts,
+		); err != nil {
+			t.Fatalf("seed brief %d: %v", i, err)
+		}
+	}
+
+	// Highest auto-increment id == most recently inserted brief.
+	const wantText = "brief-04"
+
+	for i := 0; i < sameSecondBriefIterations; i++ {
+		_, got, _, err := LastBrief(ctx, db, pid)
+		if err != nil {
+			t.Fatalf("LastBrief iter %d: %v", i, err)
+		}
+		if got != wantText {
+			t.Fatalf("LastBrief iter %d: got %q, want %q", i, got, wantText)
+		}
+	}
+}
+
+func TestLastBriefAt_StableOrderForSameTimestampInserts(t *testing.T) {
+	db, pid := newTestDB(t)
+	ctx := context.Background()
+
+	ts := time.Date(2026, 5, 5, 12, 0, 0, 0, time.UTC).Format(time.RFC3339Nano)
+	const n = 5
+	for i := 0; i < n; i++ {
+		text := fmt.Sprintf("brief-%02d", i)
+		if _, err := db.ExecContext(ctx,
+			`INSERT INTO task_notes (project_id, task_id, agent_id, note, created_at)
+			 VALUES (?, ?, ?, ?, ?)`,
+			pid, briefTaskID, "agent", briefPrefix+text, ts,
+		); err != nil {
+			t.Fatalf("seed brief %d: %v", i, err)
+		}
+	}
+
+	first, err := LastBriefAt(ctx, db, pid)
+	if err != nil {
+		t.Fatalf("LastBriefAt: %v", err)
+	}
+	if first.IsZero() {
+		t.Fatal("LastBriefAt returned zero time after seeding")
+	}
+
+	for i := 1; i < sameSecondBriefIterations; i++ {
+		next, err := LastBriefAt(ctx, db, pid)
+		if err != nil {
+			t.Fatalf("LastBriefAt iter %d: %v", i, err)
+		}
+		if !next.Equal(first) {
+			t.Fatalf("LastBriefAt iter %d: got %v, want %v", i, next, first)
+		}
+	}
+}
