Add type option "first_available" to sensor group in group component (#155525)

homeassistant/components/group/config_flow.py

@@ -39,6 +39,7 @@ from .valve import async_create_preview_valve
 
 _STATISTIC_MEASURES = [
     "last",
+    "first_available",
     "max",
     "mean",
     "median",

homeassistant/components/group/sensor.py

@@ -68,6 +68,8 @@ ATTR_MEAN = "mean"
 ATTR_MEDIAN = "median"
 ATTR_LAST = "last"
 ATTR_LAST_ENTITY_ID = "last_entity_id"
+ATTR_FIRST_AVAILABLE = "first_available"
+ATTR_FIRST_AVAILABLE_ENTITY_ID = "first_available_entity_id"
 ATTR_RANGE = "range"
 ATTR_STDEV = "stdev"
 ATTR_SUM = "sum"
@@ -78,6 +80,7 @@ SENSOR_TYPES = {
     ATTR_MEAN: "mean",
     ATTR_MEDIAN: "median",
     ATTR_LAST: "last",
+    ATTR_FIRST_AVAILABLE: "first_available",
     ATTR_RANGE: "range",
     ATTR_STDEV: "stdev",
     ATTR_SUM: "sum",
@@ -255,6 +258,19 @@ def calc_last(
     return attributes, last
 
 
+def calc_first_available(
+    sensor_values: list[tuple[str, float, State]],
+) -> tuple[dict[str, str | None], float | None]:
+    """Calculate first available value."""
+    first_available_entity_id: str | None = None
+    first_available: float | None = None
+    if sensor_values:
+        first_available_entity_id, first_available, _ = sensor_values[0]
+
+    attributes = {ATTR_FIRST_AVAILABLE_ENTITY_ID: first_available_entity_id}
+    return attributes, first_available
+
+
 def calc_range(
     sensor_values: list[tuple[str, float, State]],
 ) -> tuple[dict[str, str | None], float]:
@@ -309,6 +325,7 @@ CALC_TYPES: dict[
     "mean": calc_mean,
     "median": calc_median,
     "last": calc_last,
+    "first_available": calc_first_available,
     "range": calc_range,
     "stdev": calc_stdev,
     "sum": calc_sum,

homeassistant/components/group/strings.json

@@ -280,6 +280,7 @@
   "selector": {
     "type": {
       "options": {
+        "first_available": "First available",
         "last": "Most recently updated",
         "max": "Maximum",
         "mean": "Arithmetic mean",

tests/components/group/test_sensor.py

@@ -12,6 +12,7 @@ import pytest
 from homeassistant import config as hass_config
 from homeassistant.components.group import DOMAIN
 from homeassistant.components.group.sensor import (
+    ATTR_FIRST_AVAILABLE_ENTITY_ID,
     ATTR_LAST_ENTITY_ID,
     ATTR_MAX_ENTITY_ID,
     ATTR_MIN_ENTITY_ID,
@@ -86,6 +87,11 @@ def set_or_remove_state(
         ("mean", MEAN, {}),
         ("median", MEDIAN, {}),
         ("last", VALUES[2], {ATTR_LAST_ENTITY_ID: "sensor.test_3"}),
+        (
+            "first_available",
+            VALUES[0],
+            {ATTR_FIRST_AVAILABLE_ENTITY_ID: "sensor.test_1"},
+        ),
         ("range", RANGE, {}),
         ("stdev", STDEV, {}),
         ("sum", SUM_VALUE, {}),
@@ -861,6 +867,62 @@ async def test_last_sensor(hass: HomeAssistant) -> None:
         assert state.attributes.get("last_entity_id") == entity_id
 
 
+async def test_first_available_sensor(hass: HomeAssistant) -> None:
+    """Test the first available sensor."""
+    config = {
+        SENSOR_DOMAIN: {
+            "platform": DOMAIN,
+            "name": "test_first_available",
+            "type": "first_available",
+            "entities": ["sensor.test_1", "sensor.test_2", "sensor.test_3"],
+            "unique_id": "very_unique_id_first_available_sensor",
+            "ignore_non_numeric": True,
+        }
+    }
+
+    assert await async_setup_component(hass, "sensor", config)
+    await hass.async_block_till_done()
+
+    entity_ids = config["sensor"]["entities"]
+
+    # Ensure that while sensor states are being set
+    # the group will always point to the first available sensor.
+
+    for entity_id, value in dict(zip(entity_ids, VALUES, strict=False)).items():
+        hass.states.async_set(entity_id, value)
+        await hass.async_block_till_done()
+        state = hass.states.get("sensor.test_first_available")
+        assert str(float(VALUES[0])) == state.state
+        assert entity_ids[0] == state.attributes.get("first_available_entity_id")
+
+    # If the second sensor of the group becomes unavailable
+    # then the first one should still be taken.
+
+    hass.states.async_set(entity_ids[1], STATE_UNAVAILABLE)
+    await hass.async_block_till_done()
+    state = hass.states.get("sensor.test_first_available")
+    assert str(float(VALUES[0])) == state.state
+    assert entity_ids[0] == state.attributes.get("first_available_entity_id")
+
+    # If the first sensor of the group becomes now unavailable
+    # then the third one should be taken.
+
+    hass.states.async_set(entity_ids[0], STATE_UNAVAILABLE)
+    await hass.async_block_till_done()
+    state = hass.states.get("sensor.test_first_available")
+    assert str(float(VALUES[2])) == state.state
+    assert entity_ids[2] == state.attributes.get("first_available_entity_id")
+
+    # If all sensors of the group become unavailable
+    # then the group should also be unavailable.
+
+    hass.states.async_set(entity_ids[2], STATE_UNAVAILABLE)
+    await hass.async_block_till_done()
+    state = hass.states.get("sensor.test_first_available")
+    assert state.state == STATE_UNAVAILABLE
+    assert state.attributes.get("first_available_entity_id") is None
+
+
 async def test_sensors_attributes_added_when_entity_info_available(
     hass: HomeAssistant,
 ) -> None: