Files
tick-stock-panel/backend/tests/backtest/test_walkforward.py
T
im47cn e4262d9951 fix(walkforward): IS 训练折强制 position 模式, 堵前视泄漏
对抗式审查发现: WF UI 暴露 full 模式, 选中时训练折(end=train_end)未平仓的持仓
会用 train_end 之后(即 OOS 区间)的真实 K 线平仓 -> IS 分数被未来数据污染, 优化选出
的最优参数乐观偏移, 使过拟合被掩盖 (对专门检测过拟合的 WF 工具危害尤重)。

修复: IS 训练区间优化强制 mode="position" (只看正式区间表现), OOS 回测保留用户
所选 mode。新增测试: 用户选 full 时断言每折 IS 得到 position、OOS 保留 full。
2026-07-12 21:48:13 +08:00

337 lines
14 KiB
Python

"""Walk-forward 核心测试 — 滚动窗口 fold 生成 + OOS 聚合 + 编排。
被测:
- generate_folds: 滚动训练/测试窗口切分
- aggregate_oos: 从各折 OOS 结果聚合 (复利净值/IS-OOS 退化/一致性)
- WalkForwardService.run: 每折 训练区间优化 -> 测试区间 OOS 验证
"""
from __future__ import annotations
from dataclasses import dataclass
from datetime import date
import pytest
from app.backtest.walkforward import (
WalkForwardConfig,
WalkForwardService,
aggregate_oos,
generate_folds,
)
# ---------------------------------------------------------------
# fold 生成
# ---------------------------------------------------------------
def test_folds_rolling_windows():
# 1 年数据, 训练 90d / 测试 30d / 步进 30d
folds = generate_folds(date(2024, 1, 1), date(2024, 12, 31), train_days=90, test_days=30, step_days=30)
assert len(folds) > 0
f0 = folds[0]
assert f0.train_start == date(2024, 1, 1)
assert f0.train_end == date(2024, 3, 31) # +90d (2024 闰年)
assert f0.test_start == date(2024, 4, 1) # train_end + 1天 (隔断前视泄漏)
assert f0.test_end == date(2024, 5, 1) # +30d
# 滚动: 下一折训练起点 +step
assert folds[1].train_start == date(2024, 1, 31) # +30d
def test_folds_test_starts_day_after_train_end():
"""无前视泄漏: 每折 test_start 严格晚于 train_end (不共享同一天)。"""
folds = generate_folds(date(2024, 1, 1), date(2024, 12, 31), train_days=90, test_days=30, step_days=30)
for f in folds:
assert f.test_start > f.train_end
def test_folds_no_test_beyond_end():
folds = generate_folds(date(2024, 1, 1), date(2024, 12, 31), train_days=90, test_days=30, step_days=30)
for f in folds:
assert f.test_end <= date(2024, 12, 31)
def test_folds_insufficient_span_raises():
# 训练90+测试30=120d, 但只有 100d 数据 -> 0 折
with pytest.raises(ValueError, match=r"数据区间不足|至少"):
generate_folds(date(2024, 1, 1), date(2024, 4, 10), train_days=90, test_days=30, step_days=30)
def test_folds_reject_nonpositive_windows():
with pytest.raises(ValueError, match=r"必须为正"):
generate_folds(date(2024, 1, 1), date(2024, 12, 31), train_days=0, test_days=30, step_days=30)
# ---------------------------------------------------------------
# OOS 聚合
# ---------------------------------------------------------------
def _rec(index, is_score, total_return, obj):
return {
"index": index,
"test_end": date(2024, 1, 1),
"best_params": {"p": index},
"is_score": is_score,
"oos_objective": obj,
"oos_stats": {"total_return": total_return, "sortino": obj},
}
def test_aggregate_compounds_oos_returns():
recs = [_rec(0, 2.0, 0.10, 1.5), _rec(1, 2.0, -0.05, 0.8), _rec(2, 2.0, 0.08, 1.2)]
agg = aggregate_oos(recs, objective="sortino")
# 复利: 1.1 * 0.95 * 1.08 - 1
assert abs(agg["compounded_oos_return"] - (1.10 * 0.95 * 1.08 - 1)) < 1e-9
assert len(agg["oos_equity_curve"]) == 3
def test_aggregate_is_oos_degradation():
# IS 目标平均远高于 OOS -> 退化为正 (过拟合信号)
recs = [_rec(0, 3.0, 0.05, 0.5), _rec(1, 3.0, 0.02, 0.3)]
agg = aggregate_oos(recs, objective="sortino")
assert agg["avg_is_objective"] == 3.0
assert abs(agg["avg_oos_objective"] - 0.4) < 1e-9
assert agg["degradation"] > 0 # IS 3.0 - OOS 0.4 = 2.6
def test_aggregate_consistency_fraction_positive():
# consistency 按 OOS 总收益 > 0 的折占比: total_return 0.1>0, -0.1<=0, 0.1>0 -> 2/3
recs = [_rec(0, 1, 0.1, 1.5), _rec(1, 1, -0.1, -0.2), _rec(2, 1, 0.1, 0.8)]
agg = aggregate_oos(recs, objective="sortino")
assert agg["consistency"] == round(2 / 3, 4) # 0.6667
def test_aggregate_degradation_direction_aware_for_min_objective():
"""min 类目标 (avg_holding_days, 越小越好): OOS 持仓天数更大 = 退化, degradation>0。"""
# IS 持仓 3 天, OOS 持仓 5 天 (更长=更差) -> 退化
recs = [{"index": 0, "test_end": date(2024, 1, 1), "is_score": 3.0,
"oos_objective": 5.0, "oos_stats": {"total_return": 0.05}}]
agg = aggregate_oos(recs, objective="avg_holding_days", direction="min")
# 归一空间: norm(3)=-3, norm(5)=-5 -> degradation = -3 - (-5) = 2 > 0 = 退化
assert agg["degradation"] == round(2.0, 4)
def test_aggregate_empty_folds():
agg = aggregate_oos([], objective="sortino")
assert agg["n_folds"] == 0
assert agg["compounded_oos_return"] == 0.0
# ---------------------------------------------------------------
# 编排 (假 optimizer / service)
# ---------------------------------------------------------------
@dataclass
class _FakeResult:
stats: dict
error: str | None = None
class _FakeOptimizer:
"""optimize 返回受控 best_params/best_score, 记录被优化的训练区间。"""
def __init__(self):
self.train_ranges = []
self.opt_kwargs = [] # 记录每折 IS 优化收到的 backtest_kwargs (验证 mode 强制)
def optimize(self, cfg, progress_cb=None, cancel_event=None):
self.train_ranges.append((cfg.start, cfg.end))
self.opt_kwargs.append(dict(cfg.backtest_kwargs))
# best_params 随训练起点变化, best_score 固定
return {"best_params": {"p": cfg.start.month}, "best_score": 2.0, "results": [], "n_completed": 1}
# 从真实 PanelCache 取字段模板 —— 字段被重命名时本桩自动跟随, 避免 test 绿而生产 KeyError。
from app.backtest.engine import PanelCache
_ZERO_CACHE_STATS = {k: type(v)() for k, v in PanelCache().stats().items()}
class _FakeEngine:
"""最小引擎桩: 仅提供 WF 遥测所需的 cache_stats (字段同源自 PanelCache.stats)。"""
def cache_stats(self):
return dict(_ZERO_CACHE_STATS)
class _FakeService:
"""run 返回受控 OOS stats, 记录测试区间 + 收到的 params。"""
def __init__(self):
self.calls = []
self.engine = _FakeEngine()
def run(self, config, progress_cb=None, cancel_event=None):
self.calls.append({"start": config.start, "end": config.end,
"params": dict(config.params or {}), "mode": config.mode})
return _FakeResult(stats={"total_return": 0.05, "sortino": 1.0})
def _wf_cfg(**kw):
base = dict(
strategy_id="s", symbols=None, start=date(2024, 1, 1), end=date(2024, 12, 31),
param_grid={"p": [1, 2]}, objective="sortino",
train_days=90, test_days=30, step_days=30,
)
base.update(kw)
return WalkForwardConfig(**base)
def test_walkforward_optimizes_train_applies_oos():
opt, svc = _FakeOptimizer(), _FakeService()
wf = WalkForwardService(opt, svc, strategy_engine=None)
out = wf.run(_wf_cfg())
assert out["n_folds"] > 0
# 每折: optimizer 在训练区间跑, service 在测试区间用最优参数跑
assert len(opt.train_ranges) == out["n_folds"]
assert len(svc.calls) == out["n_folds"]
# OOS 回测用的是该折优化出的 best_params (来自训练起点月份)
first_fold = out["folds"][0]
assert svc.calls[0]["params"] == first_fold["best_params"]
# 训练区间与测试区间不重叠 (测试在训练之后)
assert svc.calls[0]["start"] >= opt.train_ranges[0][1]
class _CountingEngine:
"""首尾两次 cache_stats 返回不同值, 用于验证 WF 遥测差值/顺序计算 (非全零掩盖)。"""
def __init__(self):
self._n = 0
def cache_stats(self):
self._n += 1
if self._n == 1: # run 开头快照 (before)
return {"compute_seconds": 1.0, "compute_count": 2, "hit_count": 0, "reuse_count": 0}
return {"compute_seconds": 3.5, "compute_count": 7, "hit_count": 4, "reuse_count": 3} # after
def test_walkforward_cache_telemetry_computes_deltas():
"""cache_telemetry 用首尾快照差值: scans/hits/reuses/秒数 = after - before, 且方向正确。"""
opt, svc = _FakeOptimizer(), _FakeService()
svc.engine = _CountingEngine()
wf = WalkForwardService(opt, svc, strategy_engine=None)
out = wf.run(_wf_cfg())
tel = out["cache_telemetry"]
assert tel["scans"] == 5 # 7 - 2, 顺序写反会得 -5
assert tel["hits"] == 4 # 4 - 0
assert tel["single_flight_reuses"] == 3 # 3 - 0
assert abs(tel["load_panel_seconds"] - 2.5) < 1e-9 # 3.5 - 1.0
assert tel["load_panel_pct"] >= 0.0 # 扫盘耗时 / WF总耗时, 非负
def test_walkforward_forces_position_mode_for_is_optimization():
"""训练折(IS)强制 position 防前视泄漏(full 会用 OOS 区间 K 线平仓污染 IS);
OOS 回测保留用户所选 mode。"""
opt, svc = _FakeOptimizer(), _FakeService()
wf = WalkForwardService(opt, svc, strategy_engine=None)
wf.run(_wf_cfg(backtest_kwargs={"mode": "full"}))
assert len(opt.opt_kwargs) > 0 and len(svc.calls) > 0
# 用户选了 full, 但每折 IS 优化都被强制 position
assert all(kw["mode"] == "position" for kw in opt.opt_kwargs), "IS 优化未强制 position"
# OOS 回测保留用户的 full
assert all(c["mode"] == "full" for c in svc.calls), "OOS 未保留用户 mode"
def test_walkforward_reports_degradation():
opt, svc = _FakeOptimizer(), _FakeService()
wf = WalkForwardService(opt, svc, strategy_engine=None)
out = wf.run(_wf_cfg())
# IS best_score=2.0, OOS sortino=1.0 -> 退化 1.0
assert out["summary"]["avg_is_objective"] == 2.0
assert out["summary"]["avg_oos_objective"] == 1.0
assert abs(out["summary"]["degradation"] - 1.0) < 1e-9
class _NoParamsOptimizer(_FakeOptimizer):
"""模拟训练区间全组失败: best_params=None。"""
def optimize(self, cfg, progress_cb=None, cancel_event=None):
self.train_ranges.append((cfg.start, cfg.end))
return {"best_params": None, "best_score": None, "results": [], "n_completed": 0}
class _ErrorService(_FakeService):
"""模拟 OOS 回测失败。"""
def run(self, config, progress_cb=None, cancel_event=None):
self.calls.append({"start": config.start, "end": config.end, "params": dict(config.params or {})})
return _FakeResult(stats={}, error="no data")
def test_walkforward_skips_folds_without_optimized_params():
"""训练区间没优化出参数 (best_params=None) -> 跳过, 不用默认参数硬跑 OOS 伪装成有效折。"""
opt, svc = _NoParamsOptimizer(), _FakeService()
wf = WalkForwardService(opt, svc, strategy_engine=None)
out = wf.run(_wf_cfg())
assert out["n_folds"] == 0 # 无有效折
assert out["n_skipped"] > 0 # 全部跳过
assert svc.calls == [] # 不跑 OOS
assert out["summary"]["compounded_oos_return"] == 0.0 # 无效折不污染净值
def test_walkforward_skips_oos_error_folds():
"""OOS 回测失败的折 -> 跳过, 不把空/0 收益混入复利曲线。"""
opt, svc = _FakeOptimizer(), _ErrorService()
wf = WalkForwardService(opt, svc, strategy_engine=None)
out = wf.run(_wf_cfg())
assert out["n_folds"] == 0
assert out["n_skipped"] > 0
assert len(svc.calls) > 0 # OOS 跑了但失败
assert out["summary"]["compounded_oos_return"] == 0.0 # 失败折不计入
def test_walkforward_cancel_stops():
import threading
ev = threading.Event()
ev.set()
opt, svc = _FakeOptimizer(), _FakeService()
wf = WalkForwardService(opt, svc, strategy_engine=None)
out = wf.run(_wf_cfg(), cancel_event=ev)
# 取消 -> 不跑任何折
assert svc.calls == []
assert out["n_folds"] == 0
# ---------------------------------------------------------------
# API: job_key 回吐 + cancel 按 key 查表
# ---------------------------------------------------------------
def test_wf_job_key_distinguishes_windows():
from app.api.backtest import _make_wf_job_key
base = _make_wf_job_key("s", None, None, None, '{"p":[1]}', "sortino", None, "252/63/63", "sig")
assert base != _make_wf_job_key("s", None, None, None, '{"p":[1]}', "sortino", None, "120/30/30", "sig")
def test_wf_job_key_distinguishes_params_and_overrides():
"""params/overrides 不同必须产出不同 job_key —— 否则 stream 与 cancel 会错配到别的任务。"""
from app.api.backtest import _make_wf_job_key
base = _make_wf_job_key("s", None, None, None, '{"p":[1]}', "sortino", None, "252/63/63", "sig")
# params 不同 (未扫描参数固定值不同 -> 优化的策略不同)
assert base != _make_wf_job_key(
"s", None, None, None, '{"p":[1]}', "sortino", None, "252/63/63", "sig", params='{"x":1}')
# overrides 不同 (basic_filter/信号/风控 不同)
assert base != _make_wf_job_key(
"s", None, None, None, '{"p":[1]}', "sortino", None, "252/63/63", "sig", overrides='{"score_min":5}')
# 相同 params/overrides 必须稳定一致 (stream 端与 cancel 端对齐前提)
k = _make_wf_job_key("s", None, None, None, '{"p":[1]}', "sortino", None, "252/63/63", "sig", params='{"x":1}')
assert k == _make_wf_job_key(
"s", None, None, None, '{"p":[1]}', "sortino", None, "252/63/63", "sig", params='{"x":1}')
def test_wf_cancel_by_echoed_key():
import asyncio
from app.api.backtest import _BacktestJob, _running_jobs, walkforward_cancel
class _Req:
def __init__(self, body):
self._body = body
async def json(self):
return self._body
key = "wfkey_test_1"
_running_jobs[key] = _BacktestJob(key)
try:
res = asyncio.run(walkforward_cancel(_Req({"job_key": key})))
assert res["ok"] is True
assert _running_jobs[key].cancel_event.is_set()
res2 = asyncio.run(walkforward_cancel(_Req({"job_key": "nope"})))
assert res2["ok"] is False
finally:
_running_jobs.pop(key, None)