Remove None support from ESPHome supported_frequency_ranges

Always return frequency ranges from device info, matching the
updated RadioFrequencyTransmitterEntity contract.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.core_files.yaml

@@ -36,6 +36,7 @@ base_platforms: &base_platforms
   - homeassistant/components/image_processing/**
   - homeassistant/components/infrared/**
   - homeassistant/components/lawn_mower/**
+  - homeassistant/components/radio_frequency/**
   - homeassistant/components/light/**
   - homeassistant/components/lock/**
   - homeassistant/components/media_player/**

homeassistant/components/esphome/entry_data.py

@@ -35,6 +35,7 @@ from aioesphomeapi import (
     MediaPlayerInfo,
     MediaPlayerSupportedFormat,
     NumberInfo,
+    RadioFrequencyInfo,
     SelectInfo,
     SensorInfo,
     SensorState,
@@ -88,6 +89,7 @@ INFO_TYPE_TO_PLATFORM: dict[type[EntityInfo], Platform] = {
     FanInfo: Platform.FAN,
     InfraredInfo: Platform.INFRARED,
     LightInfo: Platform.LIGHT,
+    RadioFrequencyInfo: Platform.RADIO_FREQUENCY,
     LockInfo: Platform.LOCK,
     MediaPlayerInfo: Platform.MEDIA_PLAYER,
     NumberInfo: Platform.NUMBER,

homeassistant/components/esphome/radio_frequency.py

@@ -0,0 +1,79 @@
+"""Radio Frequency platform for ESPHome."""
+
+from __future__ import annotations
+
+from functools import partial
+import logging
+
+from aioesphomeapi import (
+    EntityState,
+    RadioFrequencyCapability,
+    RadioFrequencyInfo,
+    RadioFrequencyModulation,
+)
+from rf_protocols import ModulationType, RadioFrequencyCommand
+
+from homeassistant.components.radio_frequency import RadioFrequencyTransmitterEntity
+from homeassistant.core import callback
+
+from .entity import (
+    EsphomeEntity,
+    convert_api_error_ha_error,
+    platform_async_setup_entry,
+)
+
+_LOGGER = logging.getLogger(__name__)
+
+PARALLEL_UPDATES = 0
+
+MODULATION_TYPE_TO_ESPHOME: dict[ModulationType, RadioFrequencyModulation] = {
+    ModulationType.OOK: RadioFrequencyModulation.OOK,
+}
+
+
+class EsphomeRadioFrequencyEntity(
+    EsphomeEntity[RadioFrequencyInfo, EntityState], RadioFrequencyTransmitterEntity
+):
+    """ESPHome radio frequency entity using native API."""
+
+    @property
+    def supported_frequency_ranges(self) -> list[tuple[int, int]]:
+        """Return supported frequency ranges from device info."""
+        return [(self._static_info.frequency_min, self._static_info.frequency_max)]
+
+    @callback
+    def _on_device_update(self) -> None:
+        """Call when device updates or entry data changes."""
+        super()._on_device_update()
+        if self._entry_data.available:
+            self.async_write_ha_state()
+
+    @convert_api_error_ha_error
+    async def async_send_command(self, command: RadioFrequencyCommand) -> None:
+        """Send an RF command."""
+        timings = [
+            interval
+            for timing in command.get_raw_timings()
+            for interval in (timing.high_us, -timing.low_us)
+        ]
+        _LOGGER.debug("Sending RF command: %s", timings)
+
+        self._client.radio_frequency_transmit_raw_timings(
+            self._static_info.key,
+            frequency=command.frequency,
+            timings=timings,
+            modulation=MODULATION_TYPE_TO_ESPHOME[command.modulation],
+            repeat_count=command.repeat_count + 1,
+            device_id=self._static_info.device_id,
+        )
+
+
+async_setup_entry = partial(
+    platform_async_setup_entry,
+    info_type=RadioFrequencyInfo,
+    entity_type=EsphomeRadioFrequencyEntity,
+    state_type=EntityState,
+    info_filter=lambda info: bool(
+        info.capabilities & RadioFrequencyCapability.TRANSMITTER
+    ),
+)

homeassistant/components/radio_frequency/__init__.py

@@ -0,0 +1,189 @@
+"""Provides functionality to interact with radio frequency devices."""
+
+from __future__ import annotations
+
+from abc import abstractmethod
+from datetime import timedelta
+import logging
+from typing import final
+
+from rf_protocols import ModulationType, RadioFrequencyCommand
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import STATE_UNAVAILABLE
+from homeassistant.core import Context, HomeAssistant, callback
+from homeassistant.exceptions import HomeAssistantError
+from homeassistant.helpers import config_validation as cv, entity_registry as er
+from homeassistant.helpers.entity import EntityDescription
+from homeassistant.helpers.entity_component import EntityComponent
+from homeassistant.helpers.restore_state import RestoreEntity
+from homeassistant.helpers.typing import ConfigType
+from homeassistant.util import dt as dt_util
+from homeassistant.util.hass_dict import HassKey
+
+from .const import DOMAIN
+
+__all__ = [
+    "DOMAIN",
+    "ModulationType",
+    "RadioFrequencyTransmitterEntity",
+    "RadioFrequencyTransmitterEntityDescription",
+    "async_get_transmitters",
+    "async_send_command",
+]
+
+_LOGGER = logging.getLogger(__name__)
+
+DATA_COMPONENT: HassKey[EntityComponent[RadioFrequencyTransmitterEntity]] = HassKey(
+    DOMAIN
+)
+ENTITY_ID_FORMAT = DOMAIN + ".{}"
+PLATFORM_SCHEMA = cv.PLATFORM_SCHEMA
+PLATFORM_SCHEMA_BASE = cv.PLATFORM_SCHEMA_BASE
+SCAN_INTERVAL = timedelta(seconds=30)
+
+
+async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
+    """Set up the radio_frequency domain."""
+    component = hass.data[DATA_COMPONENT] = EntityComponent[
+        RadioFrequencyTransmitterEntity
+    ](_LOGGER, DOMAIN, hass, SCAN_INTERVAL)
+    await component.async_setup(config)
+
+    return True
+
+
+async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
+    """Set up a config entry."""
+    return await hass.data[DATA_COMPONENT].async_setup_entry(entry)
+
+
+async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
+    """Unload a config entry."""
+    return await hass.data[DATA_COMPONENT].async_unload_entry(entry)
+
+
+@callback
+def async_get_transmitters(
+    hass: HomeAssistant,
+    frequency: int,
+    modulation: ModulationType,
+) -> list[str]:
+    """Get entity IDs of all RF transmitters supporting the given frequency.
+
+    An empty list means no compatible transmitters.
+
+    Raises:
+        HomeAssistantError: If no transmitters exist.
+    """
+    component = hass.data.get(DATA_COMPONENT)
+    if component is None:
+        raise HomeAssistantError(
+            translation_domain=DOMAIN,
+            translation_key="component_not_loaded",
+        )
+
+    entities = list(component.entities)
+    if not entities:
+        raise HomeAssistantError(
+            translation_domain=DOMAIN,
+            translation_key="no_transmitters",
+        )
+
+    return [
+        entity.entity_id
+        for entity in entities
+        if any(
+            low <= frequency <= high for low, high in entity.supported_frequency_ranges
+        )
+    ]
+
+
+async def async_send_command(
+    hass: HomeAssistant,
+    entity_id_or_uuid: str,
+    command: RadioFrequencyCommand,
+    context: Context | None = None,
+) -> None:
+    """Send an RF command to the specified radio_frequency entity.
+
+    Raises:
+        HomeAssistantError: If the radio_frequency entity is not found.
+    """
+    component = hass.data.get(DATA_COMPONENT)
+    if component is None:
+        raise HomeAssistantError(
+            translation_domain=DOMAIN,
+            translation_key="component_not_loaded",
+        )
+
+    ent_reg = er.async_get(hass)
+    entity_id = er.async_validate_entity_id(ent_reg, entity_id_or_uuid)
+    entity = component.get_entity(entity_id)
+    if entity is None:
+        raise HomeAssistantError(
+            translation_domain=DOMAIN,
+            translation_key="entity_not_found",
+            translation_placeholders={"entity_id": entity_id},
+        )
+
+    if context is not None:
+        entity.async_set_context(context)
+
+    await entity.async_send_command_internal(command)
+
+
+class RadioFrequencyTransmitterEntityDescription(
+    EntityDescription, frozen_or_thawed=True
+):
+    """Describes radio frequency transmitter entities."""
+
+
+class RadioFrequencyTransmitterEntity(RestoreEntity):
+    """Base class for radio frequency transmitter entities."""
+
+    entity_description: RadioFrequencyTransmitterEntityDescription
+    _attr_should_poll = False
+    _attr_state: None = None
+
+    __last_command_sent: str | None = None
+
+    @property
+    def supported_frequency_ranges(self) -> list[tuple[int, int]]:
+        """Return list of (min_hz, max_hz) tuples."""
+        raise NotImplementedError
+
+    @property
+    @final
+    def state(self) -> str | None:
+        """Return the entity state."""
+        return self.__last_command_sent
+
+    @final
+    async def async_send_command_internal(self, command: RadioFrequencyCommand) -> None:
+        """Send an RF command and update state.
+
+        Should not be overridden, handles setting last sent timestamp.
+        """
+        await self.async_send_command(command)
+        self.__last_command_sent = dt_util.utcnow().isoformat(timespec="milliseconds")
+        self.async_write_ha_state()
+
+    @final
+    async def async_internal_added_to_hass(self) -> None:
+        """Call when the radio frequency entity is added to hass."""
+        await super().async_internal_added_to_hass()
+        state = await self.async_get_last_state()
+        if state is not None and state.state not in (STATE_UNAVAILABLE, None):
+            self.__last_command_sent = state.state
+
+    @abstractmethod
+    async def async_send_command(self, command: RadioFrequencyCommand) -> None:
+        """Send an RF command.
+
+        Args:
+            command: The RF command to send.
+
+        Raises:
+            HomeAssistantError: If transmission fails.
+        """

homeassistant/components/radio_frequency/const.py

@@ -0,0 +1,5 @@
+"""Constants for the Radio Frequency integration."""
+
+from typing import Final
+
+DOMAIN: Final = "radio_frequency"

homeassistant/components/radio_frequency/icons.json

@@ -0,0 +1,7 @@
+{
+  "entity_component": {
+    "_": {
+      "default": "mdi:radio-tower"
+    }
+  }
+}

homeassistant/components/radio_frequency/manifest.json

@@ -0,0 +1,9 @@
+{
+  "domain": "radio_frequency",
+  "name": "Radio Frequency",
+  "codeowners": ["@home-assistant/core"],
+  "documentation": "https://www.home-assistant.io/integrations/radio_frequency",
+  "integration_type": "entity",
+  "quality_scale": "internal",
+  "requirements": ["rf-protocols==0.0.1"]
+}

homeassistant/components/radio_frequency/strings.json

@@ -0,0 +1,13 @@
+{
+  "exceptions": {
+    "component_not_loaded": {
+      "message": "Radio Frequency component not loaded"
+    },
+    "entity_not_found": {
+      "message": "Radio Frequency entity `{entity_id}` not found"
+    },
+    "no_transmitters": {
+      "message": "No Radio Frequency transmitters available"
+    }
+  }
+}

homeassistant/components/radio_frequency/translations/en.json

@@ -0,0 +1,13 @@
+{
+  "exceptions": {
+    "component_not_loaded": {
+      "message": "Radio Frequency component not loaded"
+    },
+    "entity_not_found": {
+      "message": "Radio Frequency entity `{entity_id}` not found"
+    },
+    "no_transmitters": {
+      "message": "No Radio Frequency transmitters available"
+    }
+  }
+}

homeassistant/generated/entity_platforms.py

@@ -31,6 +31,7 @@ class EntityPlatforms(StrEnum):
     IMAGE_PROCESSING = "image_processing"
     INFRARED = "infrared"
     LAWN_MOWER = "lawn_mower"
+    RADIO_FREQUENCY = "radio_frequency"
     LIGHT = "light"
     LOCK = "lock"
     MEDIA_PLAYER = "media_player"

requirements_all.txt

@@ -2831,6 +2831,9 @@ renson-endura-delta==1.7.2
 # homeassistant.components.reolink
 reolink-aio==0.19.1
 
+# homeassistant.components.radio_frequency
+rf-protocols==0.0.1
+
 # homeassistant.components.idteck_prox
 rfk101py==0.0.1
 

requirements_test_all.txt

@@ -2409,6 +2409,9 @@ renson-endura-delta==1.7.2
 # homeassistant.components.reolink
 reolink-aio==0.19.1
 
+# homeassistant.components.radio_frequency
+rf-protocols==0.0.1
+
 # homeassistant.components.rflink
 rflink==0.0.67
 

tests/components/esphome/test_radio_frequency.py

@@ -0,0 +1,211 @@
+"""Test ESPHome radio frequency platform."""
+
+from aioesphomeapi import (
+    APIClient,
+    APIConnectionError,
+    RadioFrequencyCapability,
+    RadioFrequencyInfo,
+    RadioFrequencyModulation,
+)
+import pytest
+from rf_protocols import ModulationType, OOKCommand, Timing
+
+from homeassistant.components import radio_frequency
+from homeassistant.const import STATE_UNAVAILABLE
+from homeassistant.core import HomeAssistant
+from homeassistant.exceptions import HomeAssistantError
+
+from .conftest import MockESPHomeDevice, MockESPHomeDeviceType
+
+ENTITY_ID = "radio_frequency.test_rf"
+
+
+async def _mock_rf_device(
+    mock_esphome_device: MockESPHomeDeviceType,
+    mock_client: APIClient,
+    capabilities: RadioFrequencyCapability = RadioFrequencyCapability.TRANSMITTER,
+    frequency_min: int = 433_000_000,
+    frequency_max: int = 434_000_000,
+    supported_modulations: int = 1,
+) -> MockESPHomeDevice:
+    entity_info = [
+        RadioFrequencyInfo(
+            object_id="rf",
+            key=1,
+            name="RF",
+            capabilities=capabilities,
+            frequency_min=frequency_min,
+            frequency_max=frequency_max,
+            supported_modulations=supported_modulations,
+        )
+    ]
+    return await mock_esphome_device(
+        mock_client=mock_client, entity_info=entity_info, states=[]
+    )
+
+
+@pytest.mark.parametrize(
+    ("capabilities", "entity_created"),
+    [
+        (RadioFrequencyCapability.TRANSMITTER, True),
+        (RadioFrequencyCapability.RECEIVER, False),
+        (
+            RadioFrequencyCapability.TRANSMITTER | RadioFrequencyCapability.RECEIVER,
+            True,
+        ),
+        (RadioFrequencyCapability(0), False),
+    ],
+)
+async def test_radio_frequency_entity_transmitter(
+    hass: HomeAssistant,
+    mock_client: APIClient,
+    mock_esphome_device: MockESPHomeDeviceType,
+    capabilities: RadioFrequencyCapability,
+    entity_created: bool,
+) -> None:
+    """Test radio frequency entity with transmitter capability is created."""
+    await _mock_rf_device(mock_esphome_device, mock_client, capabilities)
+
+    state = hass.states.get(ENTITY_ID)
+    assert (state is not None) == entity_created
+
+
+async def test_radio_frequency_multiple_entities_mixed_capabilities(
+    hass: HomeAssistant,
+    mock_client: APIClient,
+    mock_esphome_device: MockESPHomeDeviceType,
+) -> None:
+    """Test multiple radio frequency entities with mixed capabilities."""
+    entity_info = [
+        RadioFrequencyInfo(
+            object_id="rf_transmitter",
+            key=1,
+            name="RF Transmitter",
+            capabilities=RadioFrequencyCapability.TRANSMITTER,
+        ),
+        RadioFrequencyInfo(
+            object_id="rf_receiver",
+            key=2,
+            name="RF Receiver",
+            capabilities=RadioFrequencyCapability.RECEIVER,
+        ),
+        RadioFrequencyInfo(
+            object_id="rf_transceiver",
+            key=3,
+            name="RF Transceiver",
+            capabilities=(
+                RadioFrequencyCapability.TRANSMITTER | RadioFrequencyCapability.RECEIVER
+            ),
+        ),
+    ]
+    await mock_esphome_device(
+        mock_client=mock_client,
+        entity_info=entity_info,
+        states=[],
+    )
+
+    # Only transmitter and transceiver should be created
+    assert hass.states.get("radio_frequency.test_rf_transmitter") is not None
+    assert hass.states.get("radio_frequency.test_rf_receiver") is None
+    assert hass.states.get("radio_frequency.test_rf_transceiver") is not None
+
+
+async def test_radio_frequency_send_command_success(
+    hass: HomeAssistant,
+    mock_client: APIClient,
+    mock_esphome_device: MockESPHomeDeviceType,
+) -> None:
+    """Test sending RF command successfully."""
+    await _mock_rf_device(mock_esphome_device, mock_client)
+
+    command = OOKCommand(
+        frequency=433_920_000,
+        timings=[
+            Timing(high_us=350, low_us=1050),
+            Timing(high_us=350, low_us=350),
+        ],
+    )
+    await radio_frequency.async_send_command(hass, ENTITY_ID, command)
+
+    mock_client.radio_frequency_transmit_raw_timings.assert_called_once()
+    call_args = mock_client.radio_frequency_transmit_raw_timings.call_args
+    assert call_args[0][0] == 1  # key
+    assert call_args[1]["frequency"] == 433_920_000
+    assert call_args[1]["modulation"] == RadioFrequencyModulation.OOK
+    assert call_args[1]["repeat_count"] == 1
+    assert call_args[1]["device_id"] == 0
+    assert call_args[1]["timings"] == [350, -1050, 350, -350]
+
+
+async def test_radio_frequency_send_command_failure(
+    hass: HomeAssistant,
+    mock_client: APIClient,
+    mock_esphome_device: MockESPHomeDeviceType,
+) -> None:
+    """Test sending RF command with APIConnectionError raises HomeAssistantError."""
+    await _mock_rf_device(mock_esphome_device, mock_client)
+
+    mock_client.radio_frequency_transmit_raw_timings.side_effect = APIConnectionError(
+        "Connection lost"
+    )
+
+    command = OOKCommand(
+        frequency=433_920_000,
+        timings=[Timing(high_us=350, low_us=1050)],
+    )
+
+    with pytest.raises(HomeAssistantError) as exc_info:
+        await radio_frequency.async_send_command(hass, ENTITY_ID, command)
+    assert exc_info.value.translation_domain == "esphome"
+    assert exc_info.value.translation_key == "error_communicating_with_device"
+
+
+async def test_radio_frequency_entity_availability(
+    hass: HomeAssistant,
+    mock_client: APIClient,
+    mock_esphome_device: MockESPHomeDeviceType,
+) -> None:
+    """Test radio frequency entity becomes available after device reconnects."""
+    mock_device = await _mock_rf_device(mock_esphome_device, mock_client)
+
+    state = hass.states.get(ENTITY_ID)
+    assert state is not None
+    assert state.state != STATE_UNAVAILABLE
+
+    await mock_device.mock_disconnect(False)
+    await hass.async_block_till_done()
+
+    state = hass.states.get(ENTITY_ID)
+    assert state is not None
+    assert state.state == STATE_UNAVAILABLE
+
+    await mock_device.mock_connect()
+    await hass.async_block_till_done()
+
+    state = hass.states.get(ENTITY_ID)
+    assert state is not None
+    assert state.state != STATE_UNAVAILABLE
+
+
+async def test_radio_frequency_supported_frequency_ranges(
+    hass: HomeAssistant,
+    mock_client: APIClient,
+    mock_esphome_device: MockESPHomeDeviceType,
+) -> None:
+    """Test supported frequency ranges are exposed from device info."""
+    await _mock_rf_device(
+        mock_esphome_device,
+        mock_client,
+        frequency_min=433_000_000,
+        frequency_max=434_000_000,
+    )
+
+    transmitters = radio_frequency.async_get_transmitters(
+        hass, 433_920_000, ModulationType.OOK
+    )
+    assert len(transmitters) == 1
+
+    transmitters = radio_frequency.async_get_transmitters(
+        hass, 868_000_000, ModulationType.OOK
+    )
+    assert len(transmitters) == 0

tests/components/radio_frequency/__init__.py

@@ -0,0 +1 @@
+"""Tests for the Radio Frequency integration."""

tests/components/radio_frequency/conftest.py

@@ -0,0 +1,71 @@
+"""Common fixtures for the Radio Frequency tests."""
+
+from typing import override
+
+import pytest
+from rf_protocols import ModulationType, RadioFrequencyCommand, Timing
+
+from homeassistant.components.radio_frequency import RadioFrequencyTransmitterEntity
+from homeassistant.components.radio_frequency.const import DOMAIN
+from homeassistant.core import HomeAssistant
+from homeassistant.setup import async_setup_component
+
+
+@pytest.fixture
+async def init_integration(hass: HomeAssistant) -> None:
+    """Set up the Radio Frequency integration for testing."""
+    assert await async_setup_component(hass, DOMAIN, {})
+    await hass.async_block_till_done()
+
+
+class MockRadioFrequencyCommand(RadioFrequencyCommand):
+    """Mock RF command for testing."""
+
+    def __init__(
+        self,
+        *,
+        frequency: int = 433_920_000,
+        modulation: ModulationType = ModulationType.OOK,
+        repeat_count: int = 0,
+    ) -> None:
+        """Initialize mock command."""
+        super().__init__(
+            frequency=frequency, modulation=modulation, repeat_count=repeat_count
+        )
+
+    @override
+    def get_raw_timings(self) -> list[Timing]:
+        """Return mock timings."""
+        return [Timing(high_us=350, low_us=1050), Timing(high_us=350, low_us=350)]
+
+
+class MockRadioFrequencyEntity(RadioFrequencyTransmitterEntity):
+    """Mock radio frequency entity for testing."""
+
+    _attr_has_entity_name = True
+    _attr_name = "Test RF transmitter"
+
+    def __init__(
+        self,
+        unique_id: str,
+        frequency_ranges: list[tuple[int, int]] | None = None,
+    ) -> None:
+        """Initialize mock entity."""
+        self._attr_unique_id = unique_id
+        self._frequency_ranges = frequency_ranges or [(433_000_000, 434_000_000)]
+        self.send_command_calls: list[RadioFrequencyCommand] = []
+
+    @property
+    def supported_frequency_ranges(self) -> list[tuple[int, int]]:
+        """Return supported frequency ranges."""
+        return self._frequency_ranges
+
+    async def async_send_command(self, command: RadioFrequencyCommand) -> None:
+        """Mock send command."""
+        self.send_command_calls.append(command)
+
+
+@pytest.fixture
+def mock_rf_entity() -> MockRadioFrequencyEntity:
+    """Return a mock radio frequency entity."""
+    return MockRadioFrequencyEntity("test_rf_transmitter")

tests/components/radio_frequency/test_init.py

@@ -0,0 +1,171 @@
+"""Tests for the Radio Frequency integration setup."""
+
+from unittest.mock import AsyncMock
+
+from freezegun.api import FrozenDateTimeFactory
+import pytest
+from rf_protocols import ModulationType
+
+from homeassistant.components.radio_frequency import (
+    DATA_COMPONENT,
+    DOMAIN,
+    async_get_transmitters,
+    async_send_command,
+)
+from homeassistant.const import STATE_UNAVAILABLE, STATE_UNKNOWN
+from homeassistant.core import HomeAssistant, State
+from homeassistant.exceptions import HomeAssistantError
+from homeassistant.setup import async_setup_component
+from homeassistant.util import dt as dt_util
+
+from .conftest import MockRadioFrequencyCommand, MockRadioFrequencyEntity
+
+from tests.common import mock_restore_cache
+
+
+async def test_get_transmitters_component_not_loaded(hass: HomeAssistant) -> None:
+    """Test getting transmitters raises when the component is not loaded."""
+    with pytest.raises(HomeAssistantError, match="component_not_loaded"):
+        async_get_transmitters(hass, 433_920_000, ModulationType.OOK)
+
+
+@pytest.mark.usefixtures("init_integration")
+async def test_get_transmitters_no_entities(hass: HomeAssistant) -> None:
+    """Test getting transmitters raises when none are registered."""
+    with pytest.raises(
+        HomeAssistantError,
+        match="No Radio Frequency transmitters available",
+    ):
+        async_get_transmitters(hass, 433_920_000, ModulationType.OOK)
+
+
+@pytest.mark.usefixtures("init_integration")
+async def test_get_transmitters_with_frequency_ranges(
+    hass: HomeAssistant,
+    mock_rf_entity: MockRadioFrequencyEntity,
+) -> None:
+    """Test transmitter with frequency ranges filters correctly."""
+    component = hass.data[DATA_COMPONENT]
+    await component.async_add_entities([mock_rf_entity])
+
+    # 433.92 MHz is within 433-434 MHz range
+    result = async_get_transmitters(hass, 433_920_000, ModulationType.OOK)
+    assert result == [mock_rf_entity.entity_id]
+
+    # 868 MHz is outside the range
+    result = async_get_transmitters(hass, 868_000_000, ModulationType.OOK)
+    assert result == []
+
+
+@pytest.mark.usefixtures("init_integration")
+async def test_rf_entity_initial_state(
+    hass: HomeAssistant,
+    mock_rf_entity: MockRadioFrequencyEntity,
+) -> None:
+    """Test radio frequency entity has no state before any command is sent."""
+    component = hass.data[DATA_COMPONENT]
+    await component.async_add_entities([mock_rf_entity])
+
+    state = hass.states.get("radio_frequency.test_rf_transmitter")
+    assert state is not None
+    assert state.state == STATE_UNKNOWN
+
+
+@pytest.mark.usefixtures("init_integration")
+async def test_async_send_command_success(
+    hass: HomeAssistant,
+    mock_rf_entity: MockRadioFrequencyEntity,
+    freezer: FrozenDateTimeFactory,
+) -> None:
+    """Test sending command via async_send_command helper."""
+    component = hass.data[DATA_COMPONENT]
+    await component.async_add_entities([mock_rf_entity])
+
+    now = dt_util.utcnow()
+    freezer.move_to(now)
+
+    command = MockRadioFrequencyCommand(frequency=433_920_000)
+    await async_send_command(hass, mock_rf_entity.entity_id, command)
+
+    assert len(mock_rf_entity.send_command_calls) == 1
+    assert mock_rf_entity.send_command_calls[0] is command
+
+    state = hass.states.get("radio_frequency.test_rf_transmitter")
+    assert state is not None
+    assert state.state == now.isoformat(timespec="milliseconds")
+
+
+@pytest.mark.usefixtures("init_integration")
+async def test_async_send_command_error_does_not_update_state(
+    hass: HomeAssistant,
+    mock_rf_entity: MockRadioFrequencyEntity,
+) -> None:
+    """Test that state is not updated when async_send_command raises an error."""
+    component = hass.data[DATA_COMPONENT]
+    await component.async_add_entities([mock_rf_entity])
+
+    state = hass.states.get("radio_frequency.test_rf_transmitter")
+    assert state is not None
+    assert state.state == STATE_UNKNOWN
+
+    command = MockRadioFrequencyCommand(frequency=433_920_000)
+
+    mock_rf_entity.async_send_command = AsyncMock(
+        side_effect=HomeAssistantError("Transmission failed")
+    )
+
+    with pytest.raises(HomeAssistantError, match="Transmission failed"):
+        await async_send_command(hass, mock_rf_entity.entity_id, command)
+
+    state = hass.states.get("radio_frequency.test_rf_transmitter")
+    assert state is not None
+    assert state.state == STATE_UNKNOWN
+
+
+@pytest.mark.usefixtures("init_integration")
+async def test_async_send_command_entity_not_found(hass: HomeAssistant) -> None:
+    """Test async_send_command raises error when entity not found."""
+    command = MockRadioFrequencyCommand(frequency=433_920_000)
+
+    with pytest.raises(
+        HomeAssistantError,
+        match="Radio Frequency entity `radio_frequency.nonexistent_entity` not found",
+    ):
+        await async_send_command(hass, "radio_frequency.nonexistent_entity", command)
+
+
+async def test_async_send_command_component_not_loaded(hass: HomeAssistant) -> None:
+    """Test async_send_command raises error when component not loaded."""
+    command = MockRadioFrequencyCommand(frequency=433_920_000)
+
+    with pytest.raises(HomeAssistantError, match="component_not_loaded"):
+        await async_send_command(hass, "radio_frequency.some_entity", command)
+
+
+@pytest.mark.parametrize(
+    ("restored_value", "expected_state"),
+    [
+        ("2026-01-01T12:00:00.000+00:00", "2026-01-01T12:00:00.000+00:00"),
+        (STATE_UNAVAILABLE, STATE_UNKNOWN),
+    ],
+)
+async def test_rf_entity_state_restore(
+    hass: HomeAssistant,
+    mock_rf_entity: MockRadioFrequencyEntity,
+    restored_value: str,
+    expected_state: str,
+) -> None:
+    """Test radio frequency entity state restore."""
+    mock_restore_cache(
+        hass, [State("radio_frequency.test_rf_transmitter", restored_value)]
+    )
+
+    assert await async_setup_component(hass, DOMAIN, {})
+    await hass.async_block_till_done()
+
+    component = hass.data[DATA_COMPONENT]
+    await component.async_add_entities([mock_rf_entity])
+
+    state = hass.states.get("radio_frequency.test_rf_transmitter")
+    assert state is not None
+    assert state.state == expected_state