Enable basic type checking for mqtt (#52463)

* Enable basic type checking for mqtt

* Tweak

homeassistant/components/mqtt/__init__.py

@@ -9,7 +9,7 @@ import logging
 from operator import attrgetter
 import ssl
 import time
-from typing import Any, Callable, Union
+from typing import Any, Awaitable, Callable, Union, cast
 import uuid
 
 import attr
@@ -73,7 +73,12 @@ from .const import (
     PROTOCOL_311,
 )
 from .discovery import LAST_DISCOVERY
-from .models import Message, MessageCallbackType, PublishPayloadType
+from .models import (
+    AsyncMessageCallbackType,
+    Message,
+    MessageCallbackType,
+    PublishPayloadType,
+)
 from .util import _VALID_QOS_SCHEMA, valid_publish_topic, valid_subscribe_topic
 
 _LOGGER = logging.getLogger(__name__)
@@ -284,26 +289,36 @@ def async_publish_template(
     hass.async_create_task(hass.services.async_call(DOMAIN, SERVICE_PUBLISH, data))
 
 
-def wrap_msg_callback(msg_callback: MessageCallbackType) -> MessageCallbackType:
+AsyncDeprecatedMessageCallbackType = Callable[
+    [str, PublishPayloadType, int], Awaitable[None]
+]
+DeprecatedMessageCallbackType = Callable[[str, PublishPayloadType, int], None]
+
+
+def wrap_msg_callback(
+    msg_callback: AsyncDeprecatedMessageCallbackType | DeprecatedMessageCallbackType,
+) -> AsyncMessageCallbackType | MessageCallbackType:
     """Wrap an MQTT message callback to support deprecated signature."""
     # Check for partials to properly determine if coroutine function
     check_func = msg_callback
     while isinstance(check_func, partial):
         check_func = check_func.func
 
-    wrapper_func = None
+    wrapper_func: AsyncMessageCallbackType | MessageCallbackType
     if asyncio.iscoroutinefunction(check_func):
 
         @wraps(msg_callback)
-        async def async_wrapper(msg: Any) -> None:
+        async def async_wrapper(msg: Message) -> None:
             """Call with deprecated signature."""
-            await msg_callback(msg.topic, msg.payload, msg.qos)
+            await cast(AsyncDeprecatedMessageCallbackType, msg_callback)(
+                msg.topic, msg.payload, msg.qos
+            )
 
         wrapper_func = async_wrapper
     else:
 
         @wraps(msg_callback)
-        def wrapper(msg: Any) -> None:
+        def wrapper(msg: Message) -> None:
             """Call with deprecated signature."""
             msg_callback(msg.topic, msg.payload, msg.qos)
 
@@ -315,7 +330,10 @@ def wrap_msg_callback(msg_callback: MessageCallbackType) -> MessageCallbackType:
 async def async_subscribe(
     hass: HomeAssistant,
     topic: str,
-    msg_callback: MessageCallbackType,
+    msg_callback: AsyncMessageCallbackType
+    | MessageCallbackType
+    | DeprecatedMessageCallbackType
+    | AsyncDeprecatedMessageCallbackType,
     qos: int = DEFAULT_QOS,
     encoding: str | None = "utf-8",
 ):
@@ -334,12 +352,15 @@ async def async_subscribe(
     wrapped_msg_callback = msg_callback
     # If we have 3 parameters with no default value, wrap the callback
     if non_default == 3:
+        module = inspect.getmodule(msg_callback)
         _LOGGER.warning(
             "Signature of MQTT msg_callback '%s.%s' is deprecated",
-            inspect.getmodule(msg_callback).__name__,
+            module.__name__ if module else "<unknown>",
             msg_callback.__name__,
         )
-        wrapped_msg_callback = wrap_msg_callback(msg_callback)
+        wrapped_msg_callback = wrap_msg_callback(
+            cast(DeprecatedMessageCallbackType, msg_callback)
+        )
 
     async_remove = await hass.data[DATA_MQTT].async_subscribe(
         topic,
@@ -378,16 +399,12 @@ def subscribe(
 
 async def _async_setup_discovery(
     hass: HomeAssistant, conf: ConfigType, config_entry
-) -> bool:
+) -> None:
     """Try to start the discovery of MQTT devices.
 
     This method is a coroutine.
     """
-    success: bool = await discovery.async_start(
-        hass, conf[CONF_DISCOVERY_PREFIX], config_entry
-    )
-
-    return success
+    await discovery.async_start(hass, conf[CONF_DISCOVERY_PREFIX], config_entry)
 
 
 async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
@@ -539,7 +556,7 @@ class Subscription:
     matcher: Any = attr.ib()
     job: HassJob = attr.ib()
     qos: int = attr.ib(default=0)
-    encoding: str = attr.ib(default="utf-8")
+    encoding: str | None = attr.ib(default="utf-8")
 
 
 class MQTT:
@@ -566,7 +583,7 @@ class MQTT:
         self._mqttc: mqtt.Client = None
         self._paho_lock = asyncio.Lock()
 
-        self._pending_operations = {}
+        self._pending_operations: dict[str, asyncio.Event] = {}
 
         if self.hass.state == CoreState.running:
             self._ha_started.set()
@@ -688,12 +705,12 @@ class MQTT:
             _raise_on_error(msg_info.rc)
         await self._wait_for_mid(msg_info.mid)
 
-    async def async_connect(self) -> str:
+    async def async_connect(self) -> None:
         """Connect to the host. Does not process messages yet."""
         # pylint: disable=import-outside-toplevel
         import paho.mqtt.client as mqtt
 
-        result: int = None
+        result: int | None = None
         try:
             result = await self.hass.async_add_executor_job(
                 self._mqttc.connect,
@@ -770,7 +787,7 @@ class MQTT:
         This method is a coroutine.
         """
         async with self._paho_lock:
-            result: int = None
+            result: int | None = None
             result, mid = await self.hass.async_add_executor_job(
                 self._mqttc.unsubscribe, topic
             )
@@ -781,7 +798,7 @@ class MQTT:
     async def _async_perform_subscription(self, topic: str, qos: int) -> None:
         """Perform a paho-mqtt subscription."""
         async with self._paho_lock:
-            result: int = None
+            result: int | None = None
             result, mid = await self.hass.async_add_executor_job(
                 self._mqttc.subscribe, topic, qos
             )
@@ -952,12 +969,12 @@ class MQTT:
             )
 
 
-def _raise_on_error(result_code: int) -> None:
+def _raise_on_error(result_code: int | None) -> None:
     """Raise error if error result."""
     # pylint: disable=import-outside-toplevel
     import paho.mqtt.client as mqtt
 
-    if result_code != 0:
+    if result_code is not None and result_code != 0:
         raise HomeAssistantError(
             f"Error talking to MQTT: {mqtt.error_string(result_code)}"
         )
@@ -1014,13 +1031,13 @@ async def websocket_remove_device(hass, connection, msg):
     )
 
 
-@websocket_api.async_response
 @websocket_api.websocket_command(
     {
         vol.Required("type"): "mqtt/subscribe",
         vol.Required("topic"): valid_subscribe_topic,
     }
 )
+@websocket_api.async_response
 async def websocket_subscribe(hass, connection, msg):
     """Subscribe to a MQTT topic."""
     if not connection.user.is_admin:

homeassistant/components/mqtt/binary_sensor.py

@@ -226,6 +226,7 @@ class MqttBinarySensor(MqttEntity, BinarySensorEntity):
     def available(self) -> bool:
         """Return true if the device is available and value has not expired."""
         expire_after = self._config.get(CONF_EXPIRE_AFTER)
-        return MqttAvailability.available.fget(self) and (
+        # mypy doesn't know about fget: https://github.com/python/mypy/issues/6185
+        return MqttAvailability.available.fget(self) and (  # type: ignore[attr-defined]
             expire_after is None or not self._expired
         )

homeassistant/components/mqtt/debug_info.py

@@ -1,7 +1,7 @@
 """Helper to handle a set of topics to subscribe to."""
 from collections import deque
 from functools import wraps
-from typing import Any
+from typing import Any, Callable
 
 from homeassistant.core import HomeAssistant
 
@@ -12,7 +12,9 @@ DATA_MQTT_DEBUG_INFO = "mqtt_debug_info"
 STORED_MESSAGES = 10
 
 
-def log_messages(hass: HomeAssistant, entity_id: str) -> MessageCallbackType:
+def log_messages(
+    hass: HomeAssistant, entity_id: str
+) -> Callable[[MessageCallbackType], MessageCallbackType]:
     """Wrap an MQTT message callback to support message logging."""
 
     def _log_message(msg):
@@ -24,7 +26,7 @@ def log_messages(hass: HomeAssistant, entity_id: str) -> MessageCallbackType:
         if msg not in messages:
             messages.append(msg)
 
-    def _decorator(msg_callback: MessageCallbackType):
+    def _decorator(msg_callback: MessageCallbackType) -> MessageCallbackType:
         @wraps(msg_callback)
         def wrapper(msg: Any) -> None:
             """Log message."""

homeassistant/components/mqtt/device_trigger.py

@@ -119,15 +119,15 @@ class Trigger:
     """Device trigger settings."""
 
     device_id: str = attr.ib()
-    discovery_data: dict = attr.ib()
+    discovery_data: dict | None = attr.ib()
     hass: HomeAssistant = attr.ib()
-    payload: str = attr.ib()
-    qos: int = attr.ib()
-    remove_signal: Callable[[], None] = attr.ib()
+    payload: str | None = attr.ib()
+    qos: int | None = attr.ib()
+    remove_signal: Callable[[], None] | None = attr.ib()
     subtype: str = attr.ib()
-    topic: str = attr.ib()
+    topic: str | None = attr.ib()
     type: str = attr.ib()
-    value_template: str = attr.ib()
+    value_template: str | None = attr.ib()
     trigger_instances: list[TriggerInstance] = attr.ib(factory=list)
 
     async def add_trigger(self, action, automation_info):
@@ -289,7 +289,7 @@ async def async_device_removed(hass: HomeAssistant, device_id: str):
 
 async def async_get_triggers(hass: HomeAssistant, device_id: str) -> list[dict]:
     """List device triggers for MQTT devices."""
-    triggers = []
+    triggers: list[dict] = []
 
     if DEVICE_TRIGGERS not in hass.data:
         return triggers

homeassistant/components/mqtt/discovery.py

@@ -83,7 +83,7 @@ class MQTTConfig(dict):
 
 async def async_start(  # noqa: C901
     hass: HomeAssistant, discovery_topic, config_entry=None
-) -> bool:
+) -> None:
     """Start MQTT Discovery."""
     mqtt_integrations = {}
 
@@ -298,10 +298,8 @@ async def async_start(  # noqa: C901
                 0,
             )
 
-    return True
 
-
-async def async_stop(hass: HomeAssistant) -> bool:
+async def async_stop(hass: HomeAssistant) -> None:
     """Stop MQTT Discovery."""
     if DISCOVERY_UNSUBSCRIBE in hass.data:
         for unsub in hass.data[DISCOVERY_UNSUBSCRIBE]:

homeassistant/components/mqtt/mixins.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 from abc import abstractmethod
 import json
 import logging
+from typing import Callable
 
 import voluptuous as vol
 
@@ -194,11 +195,11 @@ async def async_setup_entry_helper(hass, domain, async_setup, schema):
 class MqttAttributes(Entity):
     """Mixin used for platforms that support JSON attributes."""
 
-    _attributes_extra_blocked = frozenset()
+    _attributes_extra_blocked: frozenset[str] = frozenset()
 
     def __init__(self, config: dict) -> None:
         """Initialize the JSON attributes mixin."""
-        self._attributes = None
+        self._attributes: dict | None = None
         self._attributes_sub_state = None
         self._attributes_config = config
 
@@ -225,7 +226,7 @@ class MqttAttributes(Entity):
                 payload = msg.payload
                 if attr_tpl is not None:
                     payload = attr_tpl.async_render_with_possible_json_value(payload)
-                json_dict = json.loads(payload)
+                json_dict = json.loads(payload) if isinstance(payload, str) else None
                 if isinstance(json_dict, dict):
                     filtered_dict = {
                         k: v
@@ -272,7 +273,7 @@ class MqttAvailability(Entity):
     def __init__(self, config: dict) -> None:
         """Initialize the availability mixin."""
         self._availability_sub_state = None
-        self._available = {}
+        self._available: dict = {}
         self._available_latest = False
         self._availability_setup_from_config(config)
 
@@ -397,7 +398,7 @@ class MqttDiscoveryUpdate(Entity):
         """Initialize the discovery update mixin."""
         self._discovery_data = discovery_data
         self._discovery_update = discovery_update
-        self._remove_signal = None
+        self._remove_signal: Callable | None = None
         self._removed_from_hass = False
 
     async def async_added_to_hass(self) -> None:

homeassistant/components/mqtt/models.py

@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 import datetime as dt
-from typing import Callable, Union
+from typing import Awaitable, Callable, Union
 
 import attr
 
@@ -21,4 +21,5 @@ class Message:
     timestamp: dt.datetime | None = attr.ib(default=None)
 
 
+AsyncMessageCallbackType = Callable[[Message], Awaitable[None]]
 MessageCallbackType = Callable[[Message], None]

homeassistant/components/mqtt/sensor.py

@@ -242,6 +242,7 @@ class MqttSensor(MqttEntity, SensorEntity):
     def available(self) -> bool:
         """Return true if the device is available and value has not expired."""
         expire_after = self._config.get(CONF_EXPIRE_AFTER)
-        return MqttAvailability.available.fget(self) and (
+        # mypy doesn't know about fget: https://github.com/python/mypy/issues/6185
+        return MqttAvailability.available.fget(self) and (  # type: ignore[attr-defined]
             expire_after is None or not self._expired
         )

mypy.ini

@@ -1345,9 +1345,6 @@ ignore_errors = true
 [mypy-homeassistant.components.motion_blinds.*]
 ignore_errors = true
 
-[mypy-homeassistant.components.mqtt.*]
-ignore_errors = true
-
 [mypy-homeassistant.components.mullvad.*]
 ignore_errors = true
 

script/hassfest/mypy_config.py

@@ -125,7 +125,6 @@ IGNORED_MODULES: Final[list[str]] = [
     "homeassistant.components.minecraft_server.*",
     "homeassistant.components.mobile_app.*",
     "homeassistant.components.motion_blinds.*",
-    "homeassistant.components.mqtt.*",
     "homeassistant.components.mullvad.*",
     "homeassistant.components.neato.*",
     "homeassistant.components.ness_alarm.*",