fix(dataflows): refresh the same-day OHLCV cache

- the per-day cache was reused unconditionally, so a run started before the day's
  bar was final served that snapshot to every later run, feeding a stale close
  into technical analysis
- a present row is not sufficient either, since Yahoo publishes a partial intraday
  candle; a TTL now governs every current-day cache while historical caches stay
  immutable #1150

tests/test_ohlcv_cache_freshness.py

@@ -0,0 +1,109 @@
+"""Same-day OHLCV cache must not serve a stale snapshot all day (#1150).
+
+The cache file is keyed per day, so a run started before the day's bar was final
+would be reused by every later run, feeding a stale close into technical
+analysis. Two cases matter for a current-day request: the bar may be missing, or
+present but still in progress (Yahoo publishes a partial daily candle intraday).
+Refresh is bounded by a TTL so repeated runs cannot hammer the vendor.
+"""
+from __future__ import annotations
+
+import os
+import time
+
+import pandas as pd
+import pytest
+
+import tradingagents.dataflows.stockstats_utils as su
+
+TODAY = pd.Timestamp("2026-07-18")
+STALE = su.OHLCV_CACHE_TTL_SECONDS + 60
+
+
+def _write(tmp_path, name="cache.csv", age_seconds=0.0, last_date="2026-07-17"):
+    f = tmp_path / name
+    pd.DataFrame({"Date": [last_date], "Close": [1.0]}).to_csv(f, index=False)
+    if age_seconds:
+        old = time.time() - age_seconds
+        os.utime(f, (old, old))
+    return str(f)
+
+
+@pytest.mark.unit
+def test_current_day_cache_past_ttl_is_refreshed(tmp_path):
+    # Bar missing (rows stop at yesterday) and file older than the TTL -> refetch.
+    assert su._needs_same_day_refresh(_write(tmp_path, age_seconds=STALE), TODAY, TODAY) is True
+
+
+@pytest.mark.unit
+def test_partial_current_day_bar_is_still_refreshed(tmp_path):
+    # Today's row is present but may be an in-progress candle whose Close is not
+    # the closing price. Row inspection can't distinguish it, so the TTL governs.
+    f = _write(tmp_path, age_seconds=STALE, last_date="2026-07-18")
+    assert su._needs_same_day_refresh(f, TODAY, TODAY) is True
+
+
+@pytest.mark.unit
+def test_recent_cache_is_not_refetched(tmp_path):
+    # Written moments ago: don't hammer the vendor (weekend/holiday guard).
+    assert su._needs_same_day_refresh(_write(tmp_path), TODAY, TODAY) is False
+
+
+@pytest.mark.unit
+def test_historical_request_always_uses_cache(tmp_path):
+    # Past dates are immutable: never refetch, however old the file is.
+    past = pd.Timestamp("2026-05-01")
+    f = _write(tmp_path, age_seconds=STALE, last_date="2026-04-30")
+    assert su._needs_same_day_refresh(f, past, TODAY) is False
+
+
+@pytest.mark.unit
+def test_load_ohlcv_refetches_stale_same_day_cache(tmp_path, monkeypatch):
+    """End-to-end: the helper is actually wired into load_ohlcv's cache branch.
+
+    Without this, the unit tests above would still pass if the helper were never
+    called from the real code path.
+    """
+    monkeypatch.setattr(su, "get_config", lambda: {"data_cache_dir": str(tmp_path)})
+    monkeypatch.setattr(su.pd.Timestamp, "today", staticmethod(lambda: TODAY))
+
+    # Pre-seed the cache file load_ohlcv will look for, aged past the TTL.
+    start = (TODAY - pd.DateOffset(years=5)).strftime("%Y-%m-%d")
+    end = (TODAY + pd.Timedelta(days=1)).strftime("%Y-%m-%d")
+    cache_file = tmp_path / f"AAPL-YFin-data-{start}-{end}.csv"
+    pd.DataFrame({"Date": ["2026-07-17"], "Close": [100.0]}).to_csv(cache_file, index=False)
+    old = time.time() - STALE
+    os.utime(cache_file, (old, old))
+
+    calls = []
+
+    def _fake_download(*a, **k):
+        calls.append(1)
+        return pd.DataFrame(
+            {"Date": pd.to_datetime(["2026-07-17", "2026-07-18"]), "Close": [100.0, 222.0]}
+        ).set_index("Date")
+
+    monkeypatch.setattr(su.yf, "download", _fake_download)
+
+    out = su.load_ohlcv("AAPL", TODAY.strftime("%Y-%m-%d"))
+
+    assert calls, "stale same-day cache must trigger a refetch"
+    assert 222.0 in out["Close"].values, "refreshed close must reach the caller"
+
+
+@pytest.mark.unit
+def test_load_ohlcv_reuses_fresh_same_day_cache(tmp_path, monkeypatch):
+    # Mirror image: a fresh cache must NOT trigger a download.
+    monkeypatch.setattr(su, "get_config", lambda: {"data_cache_dir": str(tmp_path)})
+    monkeypatch.setattr(su.pd.Timestamp, "today", staticmethod(lambda: TODAY))
+
+    start = (TODAY - pd.DateOffset(years=5)).strftime("%Y-%m-%d")
+    end = (TODAY + pd.Timedelta(days=1)).strftime("%Y-%m-%d")
+    cache_file = tmp_path / f"AAPL-YFin-data-{start}-{end}.csv"
+    pd.DataFrame({"Date": ["2026-07-18"], "Close": [100.0]}).to_csv(cache_file, index=False)
+
+    def _fail_download(*a, **k):
+        raise AssertionError("fresh cache must not refetch")
+
+    monkeypatch.setattr(su.yf, "download", _fail_download)
+    su.load_ohlcv("AAPL", TODAY.strftime("%Y-%m-%d"))