From e65ea4edb07f53fca60ccc3ebee880c5e38e132f Mon Sep 17 00:00:00 2001
From: Wu Shuwen <mikewushuwen@outlook.com>
Date: Tue, 20 Oct 2026 14:39:11 +0800
Subject: [PATCH] Yield while waiting for boiler temperature

---
 custom_components/sat/overshoot_protection.py |   1 +
 tests/test_overshoot_protection.py            | 138 ++++++++++++++++++
 2 files changed, 139 insertions(+)
 create mode 100644 tests/test_overshoot_protection.py

diff --git a/custom_components/sat/overshoot_protection.py b/custom_components/sat/overshoot_protection.py
index b3413e97..10c5f4b7 100644
--- a/custom_components/sat/overshoot_protection.py
+++ b/custom_components/sat/overshoot_protection.py
@@ -67,6 +67,7 @@ async def _wait_for_stable_temperature(self) -> None:
         """Wait until the boiler temperature stabilizes, influenced by relative modulation."""
         while not self._coordinator.boiler_temperature:
             _LOGGER.warning("Waiting for boiler temperature")
+            await asyncio.sleep(SLEEP_INTERVAL)
 
         starting_temperature = self._coordinator.boiler_temperature
         previous_average_temperature = self._coordinator.boiler_temperature
diff --git a/tests/test_overshoot_protection.py b/tests/test_overshoot_protection.py
new file mode 100644
index 00000000..4b9908ea
--- /dev/null
+++ b/tests/test_overshoot_protection.py
@@ -0,0 +1,138 @@
+"""Exercise overshoot calculation with native coordinator data updates."""
+
+import asyncio
+from contextlib import suppress
+
+import pytest
+from homeassistant.core import HomeAssistant
+
+from custom_components.sat import overshoot_protection
+from custom_components.sat.const import (
+    CONF_HEATING_SYSTEM,
+    CONF_MINIMUM_SETPOINT,
+    CONF_MQTT_TOPIC,
+    CONF_SIMULATION,
+    HEATING_SYSTEM_RADIATORS,
+    MODE_MQTT_OPENTHERM,
+)
+from custom_components.sat.coordinator import SatDataUpdateCoordinatorFactory
+from custom_components.sat.mqtt.opentherm import (
+    DATA_BOILER_TEMPERATURE,
+    DATA_CENTRAL_HEATING,
+    DATA_CONTROL_SETPOINT,
+    DATA_FLAME_ACTIVE,
+    DATA_MAXIMUM_CONTROL_SETPOINT,
+    DATA_REL_MOD_LEVEL,
+    STATE_ON,
+    SatOpenThermMqttCoordinator,
+)
+from custom_components.sat.overshoot_protection import OvershootProtection
+
+
+@pytest.fixture
+def coordinator(hass: HomeAssistant) -> SatOpenThermMqttCoordinator:
+    """Use the production coordinator without publishing device commands."""
+    result = SatDataUpdateCoordinatorFactory.resolve(
+        hass,
+        MODE_MQTT_OPENTHERM,
+        "test-gateway",
+        {
+            CONF_HEATING_SYSTEM: HEATING_SYSTEM_RADIATORS,
+            CONF_MINIMUM_SETPOINT: 57,
+            CONF_MQTT_TOPIC: "test",
+        },
+        {CONF_SIMULATION: True},
+    )
+    result.async_set_updated_data({
+        DATA_CENTRAL_HEATING: STATE_ON,
+        DATA_FLAME_ACTIVE: STATE_ON,
+        DATA_CONTROL_SETPOINT: "57",
+        DATA_MAXIMUM_CONTROL_SETPOINT: "75",
+        DATA_REL_MOD_LEVEL: "0",
+    })
+    return result
+
+
+@pytest.fixture
+def protection(
+    coordinator: SatOpenThermMqttCoordinator,
+    monkeypatch: pytest.MonkeyPatch,
+) -> OvershootProtection:
+    """Shorten the polling interval without replacing asyncio scheduling."""
+    monkeypatch.setattr(overshoot_protection, "SLEEP_INTERVAL", 0.001)
+    return OvershootProtection(coordinator, HEATING_SYSTEM_RADIATORS)
+
+
+async def _publish_temperatures(coordinator: SatOpenThermMqttCoordinator) -> None:
+    await asyncio.sleep(0.01)
+    coordinator.async_set_updated_data({DATA_BOILER_TEMPERATURE: "40.0"})
+    await asyncio.sleep(0.01)
+    coordinator.async_set_updated_data({DATA_BOILER_TEMPERATURE: "40.2"})
+
+
+@pytest.mark.parametrize("initial_temperature", [None, "0"], ids=["unavailable", "zero"])
+async def test_waits_for_delayed_temperature(
+    coordinator: SatOpenThermMqttCoordinator,
+    protection: OvershootProtection,
+    initial_temperature: str | None,
+) -> None:
+    if initial_temperature is not None:
+        coordinator.async_set_updated_data({DATA_BOILER_TEMPERATURE: initial_temperature})
+    updater = asyncio.create_task(_publish_temperatures(coordinator))
+    try:
+        result = await asyncio.wait_for(protection.calculate(), timeout=1)
+        await updater
+        assert result == 40.2
+        assert coordinator.boiler_temperature == 40.2
+    finally:
+        updater.cancel()
+        with suppress(asyncio.CancelledError):
+            await updater
+
+
+@pytest.mark.parametrize("initial_temperature", [None, "0"], ids=["unavailable", "zero"])
+async def test_missing_temperature_obeys_stable_wait_timeout(
+    coordinator: SatOpenThermMqttCoordinator,
+    protection: OvershootProtection,
+    monkeypatch: pytest.MonkeyPatch,
+    initial_temperature: str | None,
+) -> None:
+    if initial_temperature is not None:
+        coordinator.async_set_updated_data({DATA_BOILER_TEMPERATURE: initial_temperature})
+    monkeypatch.setattr(
+        overshoot_protection, "OVERSHOOT_PROTECTION_STABLE_WAIT", 0.02
+    )
+    with pytest.raises(TimeoutError):
+        await protection.calculate()
+
+
+async def test_missing_temperature_can_be_cancelled(
+    protection: OvershootProtection,
+) -> None:
+    task = asyncio.create_task(protection.calculate())
+    try:
+        await asyncio.sleep(0.01)
+        task.cancel()
+        with pytest.raises(asyncio.CancelledError):
+            await task
+        assert task.cancelled()
+    finally:
+        task.cancel()
+        with suppress(asyncio.CancelledError):
+            await task
+
+
+async def test_available_temperature_still_completes(
+    coordinator: SatOpenThermMqttCoordinator,
+    protection: OvershootProtection,
+) -> None:
+    coordinator.async_set_updated_data({DATA_BOILER_TEMPERATURE: "40.0"})
+    updater = asyncio.create_task(_publish_temperatures(coordinator))
+    try:
+        result = await asyncio.wait_for(protection.calculate(), timeout=1)
+        await updater
+        assert result == 40.2
+    finally:
+        updater.cancel()
+        with suppress(asyncio.CancelledError):
+            await updater