fix(dataflows): keep one OHLCV cache file per symbol (#1330)

- the cache file is keyed by symbol and serves only on the day it was written

tests/test_ohlcv_cache_freshness.py

@@ -1,80 +1,72 @@
-"""Same-day OHLCV cache must not serve a stale snapshot all day (#1150).
+"""The OHLCV cache: one file per symbol, fresh only on the day it was written.
 
-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.
+A current-day request also refetches past a TTL, so a run started before the
+day's bar was final is not served that snapshot all day (#1150). Keying the file
+by symbol rather than by day keeps the cache from growing a file per symbol per
+day (#1330).
 """
 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")
+NOW = pd.Timestamp("2026-07-18 12:00")
 STALE = su.OHLCV_CACHE_TTL_SECONDS + 60
 
 
-def _write(tmp_path, name="cache.csv", age_seconds=0.0, last_date="2026-07-17"):
+def _write(tmp_path, name="AAPL-YFin-data.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)
+    pd.DataFrame({"Date": [last_date], "Close": [100.0]}).to_csv(f, index=False)
+    written = NOW.timestamp() - age_seconds
+    os.utime(f, (written, written))
+    return f
+
+
+def _load(tmp_path, monkeypatch, curr_date, download):
+    monkeypatch.setattr(su, "get_config", lambda: {"data_cache_dir": str(tmp_path)})
+    monkeypatch.setattr(su.pd.Timestamp, "today", staticmethod(lambda: NOW))
+    monkeypatch.setattr(su.yf, "download", download)
+    return su.load_ohlcv("AAPL", curr_date)
+
+
+def _fail_download(*a, **k):
+    raise AssertionError("fresh cache must not refetch")
 
 
 @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.
+def test_current_day_cache_past_ttl_is_not_fresh(tmp_path):
+    # Today's bar missing or still in progress: row inspection can't tell, so the TTL governs.
+    assert su._cache_is_fresh(_write(tmp_path, age_seconds=STALE), NOW.normalize(), NOW) is False
     f = _write(tmp_path, age_seconds=STALE, last_date="2026-07-18")
-    assert su._needs_same_day_refresh(f, TODAY, TODAY) is True
+    assert su._cache_is_fresh(f, NOW.normalize(), NOW) is False
 
 
 @pytest.mark.unit
-def test_recent_cache_is_not_refetched(tmp_path):
+def test_recent_cache_is_fresh(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
+    assert su._cache_is_fresh(_write(tmp_path), NOW.normalize(), NOW) is True
 
 
 @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")
+def test_historical_request_uses_todays_cache_past_the_ttl(tmp_path):
     f = _write(tmp_path, age_seconds=STALE, last_date="2026-04-30")
-    assert su._needs_same_day_refresh(f, past, TODAY) is False
+    assert su._cache_is_fresh(f, pd.Timestamp("2026-05-01"), NOW) is True
+
+
+@pytest.mark.unit
+def test_a_download_from_an_earlier_day_is_not_fresh(tmp_path):
+    f = _write(tmp_path, age_seconds=13 * 3600)  # yesterday 23:00
+    assert su._cache_is_fresh(f, pd.Timestamp("2026-05-01"), NOW) 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))
-
+    """End-to-end: the freshness check is wired into load_ohlcv's cache branch."""
+    _write(tmp_path, age_seconds=STALE)
     calls = []
 
     def _fake_download(*a, **k):
@@ -83,27 +75,31 @@ def test_load_ohlcv_refetches_stale_same_day_cache(tmp_path, monkeypatch):
             {"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"))
-
+    out = _load(tmp_path, monkeypatch, "2026-07-18", _fake_download)
     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.
+    _write(tmp_path, last_date="2026-07-18")
+    _load(tmp_path, monkeypatch, "2026-07-18", _fail_download)
+
+
+@pytest.mark.unit
+def test_one_cache_file_per_symbol_across_days(tmp_path, monkeypatch):
+    """A later day's download replaces the symbol's file instead of adding one (#1330)."""
     monkeypatch.setattr(su, "get_config", lambda: {"data_cache_dir": str(tmp_path)})
-    monkeypatch.setattr(su.pd.Timestamp, "today", staticmethod(lambda: TODAY))
+    frame = pd.DataFrame({"Date": pd.to_datetime(["2026-07-16", "2026-07-17"]), "Close": [1.0, 2.0]})
+    downloads = []
+    monkeypatch.setattr(su.yf, "download", lambda *a, **k: downloads.append(1) or frame.set_index("Date"))
 
-    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)
+    for day in ("2026-07-18 10:00", "2026-07-19 10:00", "2026-07-20 10:00"):
+        now = pd.Timestamp(day)
+        monkeypatch.setattr(su.pd.Timestamp, "today", staticmethod(lambda now=now: now))
+        su.load_ohlcv("AAPL", "2026-07-17")
+        written = list(tmp_path.glob("AAPL-*.csv"))
+        os.utime(written[0], (now.timestamp(), now.timestamp()))
 
-    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"))
+    assert len(downloads) == 3, "each new day refetches"
+    assert [p.name for p in tmp_path.iterdir()] == ["AAPL-YFin-data.csv"]