ticker-validate: add /api/ticker/historical with weekend-walkback

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/test_ticker_validate.py

@@ -135,3 +135,110 @@ async def test_validate_seeds_universe_and_quote(tmp_path, monkeypatch):
     assert len(rows) == 1
     assert rows[0].price == 100.0
     assert rows[0].currency == "USD"
+
+
+@pytest.mark.asyncio
+async def test_historical_happy_path(monkeypatch):
+    from app.routers.ticker_validate import get_historical
+    import app.routers.ticker_validate as mod
+
+    async def _fake_hist(client, symbol, target_iso):
+        # close, currency, actual_iso
+        return 185.92, "USD", "2024-01-12"
+    monkeypatch.setattr(mod, "fetch_yahoo_historical", _fake_hist)
+
+    result = await get_historical(symbol="aapl", date="2024-01-15")
+
+    assert result["ok"] is True
+    assert result["close"] == 185.92
+    assert result["currency"] == "USD"
+    # 2024-01-15 was a Monday — but our fake says it walked back to Jan 12 (Fri).
+    assert result["actual_date"] == "2024-01-12"
+
+
+@pytest.mark.asyncio
+async def test_historical_future_date_rejected():
+    from fastapi import HTTPException
+    from app.routers.ticker_validate import get_historical
+
+    future = "2099-01-01"
+    with pytest.raises(HTTPException) as exc:
+        await get_historical(symbol="AAPL", date=future)
+    assert exc.value.status_code == 400
+    assert "future" in str(exc.value.detail).lower()
+
+
+@pytest.mark.asyncio
+async def test_historical_bad_date_format_rejected():
+    from fastapi import HTTPException
+    from app.routers.ticker_validate import get_historical
+
+    with pytest.raises(HTTPException) as exc:
+        await get_historical(symbol="AAPL", date="not-a-date")
+    assert exc.value.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_historical_no_data(monkeypatch):
+    from app.routers.ticker_validate import get_historical
+    import app.routers.ticker_validate as mod
+
+    async def _fake_hist(client, symbol, target_iso):
+        return None, None, None
+    monkeypatch.setattr(mod, "fetch_yahoo_historical", _fake_hist)
+
+    result = await get_historical(symbol="ZZZNEW", date="2020-01-15")
+    assert result["ok"] is False
+    assert "no data" in result["error"].lower()
+
+
+@pytest.mark.asyncio
+async def test_historical_provider_failure(monkeypatch):
+    import httpx
+
+    from app.routers.ticker_validate import get_historical
+    import app.routers.ticker_validate as mod
+
+    async def _fake_hist(client, symbol, target_iso):
+        raise httpx.RequestError("connection failed")
+    monkeypatch.setattr(mod, "fetch_yahoo_historical", _fake_hist)
+
+    result = await get_historical(symbol="AAPL", date="2024-01-15")
+    assert result["ok"] is False
+    assert "couldn" in result["error"].lower() or "fetch" in result["error"].lower()
+
+
+@pytest.mark.asyncio
+async def test_fetch_yahoo_historical_walks_back_to_preceding_trading_day(monkeypatch):
+    """Unit test for the helper itself: feed a hand-crafted series with a
+    weekend gap, ask for the Saturday close, expect Friday's close."""
+    from app.routers.ticker_validate import fetch_yahoo_historical
+
+    # Build a fake httpx client that returns a chart payload with a
+    # Thu-Fri-Mon-Tue series; we ask for Saturday and expect Friday.
+    thu_ts = int(datetime(2024, 1, 11, tzinfo=timezone.utc).timestamp())
+    fri_ts = int(datetime(2024, 1, 12, tzinfo=timezone.utc).timestamp())
+    mon_ts = int(datetime(2024, 1, 15, tzinfo=timezone.utc).timestamp())
+    payload = {
+        "chart": {"result": [{
+            "meta": {"currency": "USD"},
+            "timestamp": [thu_ts, fri_ts, mon_ts],
+            "indicators": {"quote": [{"close": [184.0, 185.92, 186.10]}]},
+        }]}
+    }
+
+    class _FakeResponse:
+        def __init__(self, data): self._data = data
+        def json(self): return self._data
+        def raise_for_status(self): pass
+
+    class _FakeClient:
+        async def get(self, *args, **kwargs):
+            return _FakeResponse(payload)
+
+    close, currency, actual = await fetch_yahoo_historical(
+        _FakeClient(), "AAPL", "2024-01-13",  # a Saturday
+    )
+    assert close == 185.92
+    assert currency == "USD"
+    assert actual == "2024-01-12"