Refactoring, added tests

###Fix
# In light of submitting this as a pull request to the core of HA there have been some refactoring changes to comply with HA's style requirements
#Sensor names now moved to strings file to allow for translations
#Coordinator now properly handles multiple devices
#Spelling of signal strength sensor corrected

###Feature
#Tests added

tests/test_sensor.py

@@ -0,0 +1,109 @@
+"""Test Owlet Sensor."""
+from __future__ import annotations
+
+from homeassistant.core import HomeAssistant
+
+from . import async_init_integration
+
+
+async def test_sensors_asleep(hass: HomeAssistant) -> None:
+    """Test sensor values."""
+    await async_init_integration(
+        hass, properties_fixture="update_properties_asleep.json"
+    )
+
+    assert len(hass.states.async_all("sensor")) == 8
+
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_battery_percentage").state
+        == "50.0"
+    )
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_battery_remaining").state
+        == "400.0"
+    )
+    assert hass.states.get("sensor.owlet_baby_care_sock_heart_rate").state == "97.0"
+    assert hass.states.get("sensor.owlet_baby_care_sock_o2_saturation").state == "99.0"
+    assert (
+        hass.states.get(
+            "sensor.owlet_baby_care_sock_o2_saturation_10_minute_average"
+        ).state
+        == "97.0"
+    )
+
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_signal_strength").state == "30.0"
+    )
+    assert hass.states.get("sensor.owlet_baby_care_sock_skin_temperature").state == "34"
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_sleep_state").state
+        == "light_sleep"
+    )
+
+
+async def test_sensors_awake(hass: HomeAssistant) -> None:
+    """Test sensor values."""
+    await async_init_integration(
+        hass, properties_fixture="update_properties_awake.json"
+    )
+
+    assert len(hass.states.async_all("sensor")) == 8
+
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_battery_percentage").state
+        == "80.0"
+    )
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_battery_remaining").state
+        == "600.0"
+    )
+    assert hass.states.get("sensor.owlet_baby_care_sock_heart_rate").state == "110.0"
+    assert hass.states.get("sensor.owlet_baby_care_sock_o2_saturation").state == "98.0"
+    assert (
+        hass.states.get(
+            "sensor.owlet_baby_care_sock_o2_saturation_10_minute_average"
+        ).state
+        == "98.0"
+    )
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_signal_strength").state == "34.0"
+    )
+    assert hass.states.get("sensor.owlet_baby_care_sock_skin_temperature").state == "35"
+    assert hass.states.get("sensor.owlet_baby_care_sock_sleep_state").state == "awake"
+
+
+async def test_sensors_charging(hass: HomeAssistant) -> None:
+    """Test sensor values."""
+    await async_init_integration(
+        hass, properties_fixture="update_properties_charging.json"
+    )
+
+    assert len(hass.states.async_all("sensor")) == 8
+
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_battery_percentage").state
+        == "100.0"
+    )
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_battery_remaining").state
+        == "unknown"
+    )
+    assert hass.states.get("sensor.owlet_baby_care_sock_heart_rate").state == "unknown"
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_o2_saturation").state == "unknown"
+    )
+    assert (
+        hass.states.get(
+            "sensor.owlet_baby_care_sock_o2_saturation_10_minute_average"
+        ).state
+        == "unknown"
+    )
+
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_signal_strength").state == "34.0"
+    )
+    assert (
+        hass.states.get("sensor.owlet_baby_care_sock_skin_temperature").state
+        == "unknown"
+    )
+    assert hass.states.get("sensor.owlet_baby_care_sock_sleep_state").state == "unknown"