Fix get_history_metadata() raising YFPricesMissingError for valid tickers (#2745)

tests/test_get_history_metadata.py

@@ -0,0 +1,125 @@
+"""
+Regression tests for issue #2745:
+get_history_metadata() raised YFPricesMissingError for valid tickers (e.g. ROG.SW)
+when the intraday enrichment request returned no data, even though history() had
+already populated _history_metadata with currency, exchangeName, timezone, etc.
+
+Two bugs fixed:
+  1. history() always overwrote _history_metadata with {} on a failed fetch,
+     destroying previously cached good metadata.
+  2. get_history_metadata() let the optional intraday fetch propagate
+     YFPricesMissingError instead of returning the metadata already cached.
+"""
+import unittest
+from unittest.mock import MagicMock
+
+from yfinance.scrapers.history import PriceHistory
+from yfinance.exceptions import YFPricesMissingError
+
+
+def _make_ph(json_payload):
+    """Return a PriceHistory whose HTTP layer returns json_payload."""
+    mock_resp = MagicMock()
+    mock_resp.text = ""
+    mock_resp.json.return_value = json_payload
+
+    mock_data = MagicMock()
+    mock_data.get.return_value = mock_resp
+    mock_data.cache_get.return_value = mock_resp
+
+    return PriceHistory(data=mock_data, ticker="FAKE", tz="America/New_York")
+
+
+def _good_chart(meta: dict) -> dict:
+    """Minimal Yahoo chart payload with valid meta and one price row."""
+    return {
+        "chart": {
+            "result": [{
+                "meta": meta,
+                "timestamp": [1700000000],
+                "indicators": {
+                    "quote": [{
+                        "open": [100.0],
+                        "high": [101.0],
+                        "low": [99.0],
+                        "close": [100.5],
+                        "volume": [1000000],
+                    }],
+                    "adjclose": [{"adjclose": [100.5]}],
+                },
+                "events": {},
+            }],
+            "error": None,
+        }
+    }
+
+
+_GOOD_META = {
+    "currency": "CHF",
+    "exchangeName": "EBS",
+    "exchangeTimezoneName": "Europe/Zurich",
+    "instrumentType": "EQUITY",
+    "validRanges": ["1d", "5d", "1mo", "3mo", "6mo", "1y", "2y", "5y", "10y", "ytd", "max"],
+    "regularMarketTime": 1700000000,
+    "regularMarketPrice": 250.0,
+    "priceHint": 2,
+}
+
+_EMPTY_CHART = {"chart": {"result": None, "error": None}}
+
+
+class TestMetadataNotOverwrittenOnFailure(unittest.TestCase):
+    """Fix 1: failed intraday fetch must not clobber previously cached metadata."""
+
+    def test_good_metadata_preserved_after_empty_intraday(self):
+        ph = _make_ph(_good_chart(_GOOD_META))
+        # First call: daily history succeeds and caches metadata
+        ph.history(period="1mo", raise_errors=False)
+        cached = ph._history_metadata.copy()
+        self.assertEqual(cached.get("currency"), "CHF")
+
+        # Second call: intraday returns empty chart
+        ph._data.get.return_value.json.return_value = _EMPTY_CHART
+        ph.history(period="5d", interval="1h", raise_errors=False)
+
+        # Metadata must not have been wiped out
+        self.assertEqual(ph._history_metadata.get("currency"), "CHF",
+                         "Good metadata was overwritten by an empty intraday response")
+
+    def test_metadata_set_to_empty_when_never_populated(self):
+        ph = _make_ph(_EMPTY_CHART)
+        ph.history(period="1mo", raise_errors=False)
+        # No prior metadata: it's fine to end up with {}
+        self.assertEqual(ph._history_metadata, {})
+
+
+class TestGetHistoryMetadataDoesNotRaise(unittest.TestCase):
+    """Fix 2: get_history_metadata() must not raise when intraday enrichment fails."""
+
+    def test_returns_cached_metadata_when_intraday_fails(self):
+        ph = _make_ph(_good_chart(_GOOD_META))
+        # Populate metadata via a daily history call
+        ph.history(period="1mo", raise_errors=False)
+        self.assertIsNotNone(ph._history_metadata)
+
+        # Now make the intraday enrichment call fail
+        ph._data.get.return_value.json.return_value = _EMPTY_CHART
+
+        # Should NOT raise — should return whatever metadata we have
+        try:
+            md = ph.get_history_metadata()
+        except YFPricesMissingError:
+            self.fail("get_history_metadata() raised YFPricesMissingError "
+                      "even though metadata was already cached")
+
+        self.assertIn("currency", md)
+        self.assertEqual(md["currency"], "CHF")
+
+    def test_metadata_none_when_history_never_called(self):
+        """Before any history() call, _history_metadata is None."""
+        ph = _make_ph(_EMPTY_CHART)
+        self.assertIsNone(ph._history_metadata)
+
+
+if __name__ == "__main__":
+    unittest.main()

yfinance/scrapers/history.py

@@ -244,7 +244,8 @@ def history(self, period=period_default, interval="1d",
         except Exception:
             meta = {}
 
-        self._history_metadata = meta
+        if meta or self._history_metadata is None:
+            self._history_metadata = meta
         self._history_metadata['YF repair?'] = repair
 
         intraday = params["interval"][-1] in ("m", 'h')
@@ -569,7 +570,11 @@ def get_history_metadata(self, repair=_SENTINEL_) -> dict:
                 else:
                     # default
                     repair = False
-            self._get_history_cache(period="5d", interval="1h", repair=repair)['prices']
+            try:
+                self._get_history_cache(period="5d", interval="1h", repair=repair)['prices']
+            except YFPricesMissingError:
+                # tradingPeriods is optional enrichment; return whatever metadata we already have
+                pass
 
         if self._history_metadata_formatted is False:
             self._history_metadata = utils.format_history_metadata(self._history_metadata)