fix(lotto): Phase 2 리뷰 반영 (engine_w 회차주 기준·누출제거·N+1제거·테스트 보강)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lotto/tests/test_backtest_db.py

@@ -106,6 +106,60 @@ def test_run_forward_purchase_persists_all_strategies(monkeypatch):
         assert r["n_tickets"] == 20
 
 
+def test_calibrate_winner_no_draw(monkeypatch):
+    """DB에 없는 회차 번호 → ok=False, reason='no_draw'."""
+    db = _fresh_db(monkeypatch)
+    _seed_draws(db, 40)
+    from app import backtest as bt
+    r = bt.calibrate_winner(99999)
+    assert r["ok"] is False
+    assert r["reason"] == "no_draw"
+
+
+def test_calibrate_winner_insufficient_history(monkeypatch):
+    """point-in-time 이력이 MIN_HISTORY(30) 미만인 회차 → reason='insufficient_history'.
+    draw_no=20이면 PIT 이력이 19개(draws 1~19)로 30 미만."""
+    db = _fresh_db(monkeypatch)
+    _seed_draws(db, 40)
+    from app import backtest as bt
+    r = bt.calibrate_winner(20)
+    assert r["ok"] is False
+    assert r["reason"] == "insufficient_history"
+
+
+def test_run_forward_purchase_with_trials(monkeypatch):
+    """그 주 weight_trials가 존재하면 engine_w 행의 weight_label이 'w0'..'w5' 형식이어야 한다."""
+    db = _fresh_db(monkeypatch)
+    _seed_draws(db, 40)
+    # draw 40: drw_date='2020-01-13' → week_start='2020-01-13'
+    from datetime import date, timedelta
+    draw_date = date.fromisoformat("2020-01-13")
+    ws = (draw_date - timedelta(days=draw_date.weekday())).isoformat()
+    # 해당 주에 trial 2개 심기 (day_of_week 0, 1)
+    db.save_weight_trial(ws, 0, [0.1, 0.3, 0.2, 0.2, 0.2], "perturb")
+    db.save_weight_trial(ws, 1, [0.25, 0.25, 0.25, 0.15, 0.1], "perturb")
+    from app import backtest as bt
+    res = bt.run_forward_purchase(draw_no=40, k=20, pool_n=500, sample_seed=5)
+    assert res["ok"] is True
+    rows = db.get_backtest_runs(draw_no=40)
+    engine_w_labels = {r["weight_label"] for r in rows if r["strategy"] == "engine_w"}
+    # trials가 있으므로 'base'가 아닌 'w0', 'w1' 형식이어야 한다
+    assert "base" not in engine_w_labels
+    assert any(lbl.startswith("w") for lbl in engine_w_labels)
+
+
+def test_run_forward_purchase_idempotent(monkeypatch):
+    """run_forward_purchase 두 번 호출 시 upsert — 행 수 변화 없음."""
+    db = _fresh_db(monkeypatch)
+    _seed_draws(db, 40)
+    from app import backtest as bt
+    bt.run_forward_purchase(draw_no=40, k=20, pool_n=500, sample_seed=5)
+    count_after_first = len(db.get_backtest_runs(draw_no=40))
+    bt.run_forward_purchase(draw_no=40, k=20, pool_n=500, sample_seed=5)
+    count_after_second = len(db.get_backtest_runs(draw_no=40))
+    assert count_after_second == count_after_first
+
+
 def test_get_calibrated_draw_nos(monkeypatch):
     """저장된 draw_no 집합이 get_calibrated_draw_nos에 포함되어야 한다."""
     db = _fresh_db(monkeypatch)