Return correct value for 60 minute spot prices at all times

Author: slovdahl

spothinta_api/models.py

@@ -11,13 +11,18 @@
     from zoneinfo import ZoneInfo
 
 
-def _timed_value(moment: datetime, prices: dict[datetime, float]) -> float | None:
+def _timed_value(
+    moment: datetime,
+    prices: dict[datetime, float],
+    resolution: timedelta,
+) -> float | None:
     """Return a function that returns a value at a specific time.
 
     Args:
     ----
         moment: The time to get the value for.
         prices: A dictionary with market prices.
+        resolution: The time resolution of price intervals (default: 15 minutes).
 
     Returns:
     -------
@@ -26,7 +31,7 @@ def _timed_value(moment: datetime, prices: dict[datetime, float]) -> float | Non
     """
     value = None
     for timestamp, price in prices.items():
-        future_dt = timestamp + timedelta(minutes=15)
+        future_dt = timestamp + resolution
         if timestamp <= moment < future_dt:
             value = round(price, 5)
     return value
@@ -373,7 +378,7 @@ def price_at_time(self, moment: datetime) -> float | None:
             The price at the specified time.
 
         """
-        value = _timed_value(moment, self.prices)
+        value = _timed_value(moment, self.prices, self.resolution)
         if value is not None or value == 0:
             return value
         return None

tests/test_models.py

@@ -486,6 +486,68 @@ async def test_model_dst_spring_forward_23h(aresponses: ResponsesMockServer) ->
         assert energy.average_price_today is not None
 
 
+@pytest.mark.freeze_time("2023-05-06 15:30:00+03:00")
+async def test_model_60_minute_resolution_non_interval_start(
+    aresponses: ResponsesMockServer,
+) -> None:
+    """Test 60-minute resolution when queried at mid-interval time.
+
+    Regression test: price_at_time() and current_price should work correctly
+    even when the queried moment is not at an interval start (e.g., 15:30
+    within the 15:00-16:00 hour). The interval logic should check if moment
+    falls within [start, start+resolution), using the actual resolution,
+    not hardcoded 15 minutes.
+    """
+    aresponses.add(
+        "api.spot-hinta.fi",
+        "/TodayAndDayForward",
+        "GET",
+        aresponses.Response(
+            status=200,
+            headers={"Content-Type": "application/json"},
+            text=load_fixtures("energy.json"),
+        ),
+    )
+    async with ClientSession() as session:
+        client = SpotHinta(session=session)
+        energy: Electricity = await client.energy_prices()
+        assert energy is not None
+        assert isinstance(energy, Electricity)
+        # At 15:30, we're in the 15:00-16:00 interval
+        # Should return the price for 15:00 (0.062)
+        assert energy.current_price == 0.062
+        # Also test price_at_time at a non-interval-start time
+        moment_15_30 = datetime(2023, 5, 6, 12, 30, tzinfo=timezone.utc)
+        assert energy.price_at_time(moment_15_30) == 0.062
+
+
+@pytest.mark.freeze_time("2023-05-06 15:58:00+03:00")
+async def test_model_60_minute_resolution_late_in_interval(
+    aresponses: ResponsesMockServer,
+) -> None:
+    """Test 60-minute resolution at late moment in interval.
+
+    Regression test: verifies current_price works correctly at 15:58
+    (late in the 15:00-16:00 hour), not just at mid-interval times.
+    """
+    aresponses.add(
+        "api.spot-hinta.fi",
+        "/TodayAndDayForward",
+        "GET",
+        aresponses.Response(
+            status=200,
+            headers={"Content-Type": "application/json"},
+            text=load_fixtures("energy.json"),
+        ),
+    )
+    async with ClientSession() as session:
+        client = SpotHinta(session=session)
+        energy: Electricity = await client.energy_prices()
+        assert energy is not None
+        # At 15:58, still in the 15:00-16:00 interval
+        assert energy.current_price == 0.062
+
+
 @pytest.mark.freeze_time("2026-10-25 11:00:00Z")
 async def test_model_dst_fall_back_25h(aresponses: ResponsesMockServer) -> None:
     """DST fall back (25-hour day) on 2026-10-25 in Europe/Stockholm.