From 4c51d0d2cf655518abb3604632c3cfd247e93a1d Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 3 Oct 2021 09:28:39 -1000
Subject: [PATCH] Round tplink energy sensors to prevent insignificant updates
 (#56999)

- These sensors wobble quite a bit and the precision did
  not have sensible limits which generated a massive amount
  of data in the database which was not very useful
---
 homeassistant/components/tplink/sensor.py | 10 ++++++++--
 tests/components/tplink/test_sensor.py    | 20 ++++++++++----------
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/homeassistant/components/tplink/sensor.py b/homeassistant/components/tplink/sensor.py
index 0afcf96dba5..9bd4a056d33 100644
--- a/homeassistant/components/tplink/sensor.py
+++ b/homeassistant/components/tplink/sensor.py
@@ -44,6 +44,7 @@ class TPLinkSensorEntityDescription(SensorEntityDescription):
     """Describes TPLink sensor entity."""
 
     emeter_attr: str | None = None
+    precision: int | None = None
 
 
 ENERGY_SENSORS: tuple[TPLinkSensorEntityDescription, ...] = (
@@ -54,6 +55,7 @@ ENERGY_SENSORS: tuple[TPLinkSensorEntityDescription, ...] = (
         state_class=STATE_CLASS_MEASUREMENT,
         name="Current Consumption",
         emeter_attr="power",
+        precision=1,
     ),
     TPLinkSensorEntityDescription(
         key=ATTR_TOTAL_ENERGY_KWH,
@@ -62,6 +64,7 @@ ENERGY_SENSORS: tuple[TPLinkSensorEntityDescription, ...] = (
         state_class=STATE_CLASS_TOTAL_INCREASING,
         name="Total Consumption",
         emeter_attr="total",
+        precision=3,
     ),
     TPLinkSensorEntityDescription(
         key=ATTR_TODAY_ENERGY_KWH,
@@ -69,6 +72,7 @@ ENERGY_SENSORS: tuple[TPLinkSensorEntityDescription, ...] = (
         device_class=DEVICE_CLASS_ENERGY,
         state_class=STATE_CLASS_TOTAL_INCREASING,
         name="Today's Consumption",
+        precision=3,
     ),
     TPLinkSensorEntityDescription(
         key=ATTR_VOLTAGE,
@@ -77,6 +81,7 @@ ENERGY_SENSORS: tuple[TPLinkSensorEntityDescription, ...] = (
         state_class=STATE_CLASS_MEASUREMENT,
         name="Voltage",
         emeter_attr="voltage",
+        precision=1,
     ),
     TPLinkSensorEntityDescription(
         key=ATTR_CURRENT_A,
@@ -85,6 +90,7 @@ ENERGY_SENSORS: tuple[TPLinkSensorEntityDescription, ...] = (
         state_class=STATE_CLASS_MEASUREMENT,
         name="Current",
         emeter_attr="current",
+        precision=2,
     ),
 )
 
@@ -97,11 +103,11 @@ def async_emeter_from_device(
         val = getattr(device.emeter_realtime, attr)
         if val is None:
             return None
-        return cast(float, val)
+        return round(cast(float, val), description.precision)
 
     # ATTR_TODAY_ENERGY_KWH
     if (emeter_today := device.emeter_today) is not None:
-        return cast(float, emeter_today)
+        return round(cast(float, emeter_today), description.precision)
     # today's consumption not available, when device was off all the day
     # bulb's do not report this information, so filter it out
     return None if device.is_bulb else 0.0
diff --git a/tests/components/tplink/test_sensor.py b/tests/components/tplink/test_sensor.py
index 839588d2756..5413e036d96 100644
--- a/tests/components/tplink/test_sensor.py
+++ b/tests/components/tplink/test_sensor.py
@@ -34,14 +34,14 @@ async def test_color_light_with_an_emeter(hass: HomeAssistant) -> None:
         voltage=None,
         current=5,
     )
-    bulb.emeter_today = 5000
+    bulb.emeter_today = 5000.0036
     with _patch_discovery(device=bulb), _patch_single_discovery(device=bulb):
         await async_setup_component(hass, tplink.DOMAIN, {tplink.DOMAIN: {}})
         await hass.async_block_till_done()
         await hass.async_block_till_done()
 
     expected = {
-        "sensor.my_bulb_today_s_consumption": 5000,
+        "sensor.my_bulb_today_s_consumption": 5000.004,
         "sensor.my_bulb_current": 5,
     }
     entity_id = "light.my_bulb"
@@ -69,10 +69,10 @@ async def test_plug_with_an_emeter(hass: HomeAssistant) -> None:
     plug.color_temp = None
     plug.has_emeter = True
     plug.emeter_realtime = Mock(
-        power=100,
-        total=30,
-        voltage=121,
-        current=5,
+        power=100.06,
+        total=30.0049,
+        voltage=121.19,
+        current=5.035,
     )
     plug.emeter_today = None
     with _patch_discovery(device=plug), _patch_single_discovery(device=plug):
@@ -81,11 +81,11 @@ async def test_plug_with_an_emeter(hass: HomeAssistant) -> None:
         await hass.async_block_till_done()
 
     expected = {
-        "sensor.my_plug_current_consumption": 100,
-        "sensor.my_plug_total_consumption": 30,
+        "sensor.my_plug_current_consumption": 100.1,
+        "sensor.my_plug_total_consumption": 30.005,
         "sensor.my_plug_today_s_consumption": 0.0,
-        "sensor.my_plug_voltage": 121,
-        "sensor.my_plug_current": 5,
+        "sensor.my_plug_voltage": 121.2,
+        "sensor.my_plug_current": 5.04,
     }
     entity_id = "switch.my_plug"
     state = hass.states.get(entity_id)