Move MqttServiceInfo to init.py (#60905)

Co-authored-by: epenet <epenet@users.noreply.github.com>
Co-authored-by: Paulus Schoutsen <balloob@gmail.com>

tests/components/mqtt/test_init.py

@@ -1812,3 +1812,27 @@ async def test_publish_json_from_template(hass, mqtt_mock):
 
     assert mqtt_mock.async_publish.called
     assert mqtt_mock.async_publish.call_args[0][1] == test_str
+
+
+async def test_service_info_compatibility(hass, caplog):
+    """Test compatibility with old-style dict.
+
+    To be removed in 2022.6
+    """
+    discovery_info = mqtt.MqttServiceInfo(
+        topic="tasmota/discovery/DC4F220848A2/config",
+        payload="",
+        qos=0,
+        retain=False,
+        subscribed_topic="tasmota/discovery/#",
+        timestamp=None,
+    )
+
+    # Ensure first call get logged
+    assert discovery_info["topic"] == "tasmota/discovery/DC4F220848A2/config"
+    assert "Detected code that accessed discovery_info['topic']" in caplog.text
+
+    # Ensure second call doesn't get logged
+    caplog.clear()
+    assert discovery_info["topic"] == "tasmota/discovery/DC4F220848A2/config"
+    assert "Detected code that accessed discovery_info['topic']" not in caplog.text