From 8be6f441ddc76205dad677b39668b5c5846f65bc Mon Sep 17 00:00:00 2001
From: Artur Pragacz <49985303+arturpragacz@users.noreply.github.com>
Date: Tue, 31 Mar 2026 11:53:36 +0200
Subject: [PATCH] Register condition platform upon use (#166939)

---
 homeassistant/helpers/condition.py | 25 +++++++++-----
 tests/helpers/test_condition.py    | 53 ++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+), 8 deletions(-)

diff --git a/homeassistant/helpers/condition.py b/homeassistant/helpers/condition.py
index 5cf8df5d36c7..810b8f40b732 100644
--- a/homeassistant/helpers/condition.py
+++ b/homeassistant/helpers/condition.py
@@ -230,19 +230,23 @@ async def _register_condition_platform(
     from homeassistant.components import automation  # noqa: PLC0415
 
     new_conditions: set[str] = set()
+    conditions = hass.data[CONDITIONS]
 
     if hasattr(platform, "async_get_conditions"):
-        for condition_key in await platform.async_get_conditions(hass):
+        all_conditions = await platform.async_get_conditions(hass)
+        for condition_key in all_conditions:
             condition_key = get_absolute_description_key(
                 integration_domain, condition_key
             )
-            hass.data[CONDITIONS][condition_key] = integration_domain
-            new_conditions.add(condition_key)
+            if condition_key not in conditions:
+                conditions[condition_key] = integration_domain
+                new_conditions.add(condition_key)
         if not new_conditions:
-            _LOGGER.debug(
-                "Integration %s returned no conditions in async_get_conditions",
-                integration_domain,
-            )
+            if not all_conditions:
+                _LOGGER.debug(
+                    "Integration %s returned no conditions in async_get_conditions",
+                    integration_domain,
+                )
             return
     else:
         _LOGGER.debug(
@@ -821,12 +825,17 @@ async def _async_get_condition_platform(
             f'Invalid condition "{condition_key}" specified'
         ) from None
     try:
-        return platform, await integration.async_get_platform("condition")
+        platform_module = await integration.async_get_platform("condition")
     except ImportError:
         raise HomeAssistantError(
             f"Integration '{platform}' does not provide condition support"
         ) from None
 
+    # Ensure conditions are registered so descriptions can be loaded
+    await _register_condition_platform(hass, platform, platform_module)
+
+    return platform, platform_module
+
 
 async def _async_get_checker(condition: Condition) -> ConditionCheckerType:
     new_checker = await condition.async_get_checker()
diff --git a/tests/helpers/test_condition.py b/tests/helpers/test_condition.py
index e21a3d048d00..ab5fe80825c1 100644
--- a/tests/helpers/test_condition.py
+++ b/tests/helpers/test_condition.py
@@ -48,9 +48,11 @@ from homeassistant.helpers.condition import (
     ATTR_BEHAVIOR,
     BEHAVIOR_ALL,
     BEHAVIOR_ANY,
+    CONDITIONS,
     Condition,
     ConditionChecker,
     EntityNumericalConditionWithUnitBase,
+    _async_get_condition_platform,
     async_validate_condition_config,
     make_entity_numerical_condition,
     make_entity_numerical_condition_with_unit,
@@ -2276,6 +2278,57 @@ async def test_platform_backwards_compatibility_for_new_style_configs(
     assert result == config_old_style
 
 
+async def test_get_condition_platform_registers_conditions(
+    hass: HomeAssistant,
+) -> None:
+    """Test _async_get_condition_platform registers conditions and notifies subscribers."""
+
+    class MockCondition(Condition):
+        """Mock condition."""
+
+        @classmethod
+        async def async_validate_config(
+            cls, hass: HomeAssistant, config: ConfigType
+        ) -> ConfigType:
+            return config
+
+        async def async_get_checker(self) -> ConditionChecker:
+            return lambda **kwargs: True
+
+    async def async_get_conditions(
+        hass: HomeAssistant,
+    ) -> dict[str, type[Condition]]:
+        return {"cond_a": MockCondition, "cond_b": MockCondition}
+
+    mock_integration(hass, MockModule("test"))
+    mock_platform(
+        hass, "test.condition", Mock(async_get_conditions=async_get_conditions)
+    )
+
+    subscriber_events: list[set[str]] = []
+
+    async def subscriber(new_conditions: set[str]) -> None:
+        subscriber_events.append(new_conditions)
+
+    condition.async_subscribe_platform_events(hass, subscriber)
+
+    assert "test.cond_a" not in hass.data[CONDITIONS]
+    assert "test.cond_b" not in hass.data[CONDITIONS]
+
+    # First call registers all conditions from the platform and notifies subscribers
+    await _async_get_condition_platform(hass, "test.cond_a")
+
+    assert hass.data[CONDITIONS]["test.cond_a"] == "test"
+    assert hass.data[CONDITIONS]["test.cond_b"] == "test"
+    assert len(subscriber_events) == 1
+    assert subscriber_events[0] == {"test.cond_a", "test.cond_b"}
+
+    # Subsequent calls are idempotent — no re-registration or re-notification
+    await _async_get_condition_platform(hass, "test.cond_a")
+    await _async_get_condition_platform(hass, "test.cond_b")
+    assert len(subscriber_events) == 1
+
+
 @pytest.mark.parametrize("enabled_value", [True, "{{ 1 == 1 }}"])
 async def test_enabled_condition(
     hass: HomeAssistant, enabled_value: bool | str