Away user has null data

[ron7684]

A shared bed with an away user returns null data that is not properly handled by HA

Logger: homeassistant
Source: components/sensor/__init__.py:664
First occurred: 2:44:02 PM (56 occurrences)
Last logged: 7:20:34 PM

Error doing job: Task exception was never retrieved (None)
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/sensor/__init__.py", line 662, in state
    numerical_value = float(value)  # type:ignore[arg-type]
                      ^^^^^^^^^^^^
ValueError: could not convert string to float: 'None'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 258, in _handle_refresh_interval
    await self._async_refresh(log_failures=True, scheduled=True)
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 453, in _async_refresh
    self.async_update_listeners()
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 168, in async_update_listeners
    update_callback()
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 533, in _handle_coordinator_update
    self.async_write_ha_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1005, in async_write_ha_state
    self._async_write_ha_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1130, in _async_write_ha_state
    self.__async_calculate_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1067, in __async_calculate_state
    state = self._stringify_state(available)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1011, in _stringify_state
    if (state := self.state) is None:
                 ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/sensor/__init__.py", line 664, in state
    raise ValueError(
ValueError: Sensor sensor.guest_s_hrv has device class 'None', state class 'measurement' unit 'ms' and suggested precision 'None' thus indicating it has a numeric value; however, it has the non-numeric value: 'None' (<class 'str'>)

[ron7684]

Logger: homeassistant.components.sensor
Source: helpers/entity_platform.py:598
integration: Sensor (documentation, issues)
First occurred: 2:39:00 PM (2 occurrences)
Last logged: 2:39:00 PM

Error adding entity sensor.guest_s_hrv for domain sensor with platform eight_sleep
Error adding entity sensor.guest_s_breath_rate for domain sensor with platform eight_sleep
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/sensor/__init__.py", line 662, in state
    numerical_value = float(value)  # type:ignore[arg-type]
                      ^^^^^^^^^^^^
ValueError: could not convert string to float: 'None'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 598, in _async_add_entities
    await coro
  File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 912, in _async_add_entity
    await entity.add_to_platform_finish()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1366, in add_to_platform_finish
    self.async_write_ha_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1005, in async_write_ha_state
    self._async_write_ha_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1130, in _async_write_ha_state
    self.__async_calculate_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1067, in __async_calculate_state
    state = self._stringify_state(available)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1011, in _stringify_state
    if (state := self.state) is None:
                 ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/sensor/__init__.py", line 664, in state
    raise ValueError(
ValueError: Sensor sensor.guest_s_hrv has device class 'None', state class 'measurement' unit 'ms' and suggested precision 'None' thus indicating it has a numeric value; however, it has the non-numeric value: 'None' (<class 'str'>)

[lukas-clarke]

This seems like a low priority issue. We want the values to be None and to show "Unknown" when away because they are not valid when set to away.
The fix for this would look like catching this error in order to not have it dirty the logs. But the underlying logic isn't really causing an issue.