Add native ESPHome API binary sensor (#19371)

* Add esphomelib native API binary sensor

* Fixes

* 🚑 Lint

homeassistant/components/binary_sensor/esphome.py

@@ -0,0 +1,63 @@
+"""Support for ESPHome binary sensors."""
+import logging
+
+from typing import TYPE_CHECKING, Optional
+
+from homeassistant.components.binary_sensor import BinarySensorDevice
+from homeassistant.components.esphome import EsphomeEntity, \
+    platform_async_setup_entry
+
+if TYPE_CHECKING:
+    # pylint: disable=unused-import
+    from aioesphomeapi import BinarySensorInfo, BinarySensorState  # noqa
+
+DEPENDENCIES = ['esphome']
+_LOGGER = logging.getLogger(__name__)
+
+
+async def async_setup_entry(hass, entry, async_add_entities):
+    """Set up ESPHome binary sensors based on a config entry."""
+    # pylint: disable=redefined-outer-name
+    from aioesphomeapi import BinarySensorInfo, BinarySensorState  # noqa
+
+    await platform_async_setup_entry(
+        hass, entry, async_add_entities,
+        component_key='binary_sensor',
+        info_type=BinarySensorInfo, entity_type=EsphomeBinarySensor,
+        state_type=BinarySensorState
+    )
+
+
+class EsphomeBinarySensor(EsphomeEntity, BinarySensorDevice):
+    """A binary sensor implementation for ESPHome."""
+
+    @property
+    def _static_info(self) -> 'BinarySensorInfo':
+        return super()._static_info
+
+    @property
+    def _state(self) -> Optional['BinarySensorState']:
+        return super()._state
+
+    @property
+    def is_on(self):
+        """Return true if the binary sensor is on."""
+        if self._static_info.is_status_binary_sensor:
+            # Status binary sensors indicated connected state.
+            # So in their case what's usually _availability_ is now state
+            return self._entry_data.available
+        if self._state is None:
+            return None
+        return self._state.state
+
+    @property
+    def device_class(self):
+        """Return the class of this device, from component DEVICE_CLASSES."""
+        return self._static_info.device_class
+
+    @property
+    def available(self):
+        """Return True if entity is available."""
+        if self._static_info.is_status_binary_sensor:
+            return True
+        return super(EsphomeEntity, self).available

homeassistant/components/esphome/__init__.py

@@ -31,7 +31,10 @@ DISPATCHER_ON_LIST = 'esphome_{entry_id}_on_list'
 DISPATCHER_ON_DEVICE_UPDATE = 'esphome_{entry_id}_on_device_update'
 DISPATCHER_ON_STATE = 'esphome_{entry_id}_on_state'
 # The HA component types this integration supports
-HA_COMPONENTS = ['sensor']
+HA_COMPONENTS = [
+    'sensor',
+    'binary_sensor'
+]
 
 _LOGGER = logging.getLogger(__name__)