From 1ca9deb520101a105d6653fb88146575529174e9 Mon Sep 17 00:00:00 2001
From: Diogo Gomes <diogogomes@gmail.com>
Date: Tue, 7 Sep 2021 07:12:54 +0100
Subject: [PATCH] Integration Sensor Initial State (#55875)

* initial state is UNAVAILABLE

* update tests
---
 homeassistant/components/integration/sensor.py | 11 ++++++++---
 tests/components/integration/test_sensor.py    |  7 +++----
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/homeassistant/components/integration/sensor.py b/homeassistant/components/integration/sensor.py
index d9a41cf714e..c0e4a723515 100644
--- a/homeassistant/components/integration/sensor.py
+++ b/homeassistant/components/integration/sensor.py
@@ -106,7 +106,7 @@ class IntegrationSensor(RestoreEntity, SensorEntity):
         """Initialize the integration sensor."""
         self._sensor_source_id = source_entity
         self._round_digits = round_digits
-        self._state = 0
+        self._state = STATE_UNAVAILABLE
         self._method = integration_method
 
         self._name = name if name is not None else f"{source_entity} integral"
@@ -187,7 +187,10 @@ class IntegrationSensor(RestoreEntity, SensorEntity):
             except AssertionError as err:
                 _LOGGER.error("Could not calculate integral: %s", err)
             else:
-                self._state += integral
+                if isinstance(self._state, Decimal):
+                    self._state += integral
+                else:
+                    self._state = integral
                 self.async_write_ha_state()
 
         async_track_state_change_event(
@@ -202,7 +205,9 @@ class IntegrationSensor(RestoreEntity, SensorEntity):
     @property
     def native_value(self):
         """Return the state of the sensor."""
-        return round(self._state, self._round_digits)
+        if isinstance(self._state, Decimal):
+            return round(self._state, self._round_digits)
+        return self._state
 
     @property
     def native_unit_of_measurement(self):
diff --git a/tests/components/integration/test_sensor.py b/tests/components/integration/test_sensor.py
index 5eff62835ba..354f4af95ba 100644
--- a/tests/components/integration/test_sensor.py
+++ b/tests/components/integration/test_sensor.py
@@ -81,7 +81,6 @@ async def test_restore_state(hass: HomeAssistant) -> None:
             "platform": "integration",
             "name": "integration",
             "source": "sensor.power",
-            "unit": ENERGY_KILO_WATT_HOUR,
             "round": 2,
         }
     }
@@ -116,7 +115,6 @@ async def test_restore_state_failed(hass: HomeAssistant) -> None:
             "platform": "integration",
             "name": "integration",
             "source": "sensor.power",
-            "unit": ENERGY_KILO_WATT_HOUR,
         }
     }
 
@@ -125,9 +123,10 @@ async def test_restore_state_failed(hass: HomeAssistant) -> None:
 
     state = hass.states.get("sensor.integration")
     assert state
-    assert state.state == "0"
-    assert state.attributes.get("unit_of_measurement") == ENERGY_KILO_WATT_HOUR
+    assert state.state == "unavailable"
+    assert state.attributes.get("unit_of_measurement") is None
     assert state.attributes.get("state_class") == STATE_CLASS_TOTAL
+
     assert "device_class" not in state.attributes