Add AsusWRT Devices Connected Sensor

[timmo001]

Proposed change

Adds a new sensor with the number of connected devices.

Type of change

• New feature (which adds functionality to an existing integration)

Example entry for configuration.yaml:

# Example configuration.yaml
asuswrt:
  host: !secret asuswrt_host
  username: !secret asuswrt_username
  password: !secret asuswrt_password
  protocol: ssh
  mode: router
  sensors:
    - devices
    - upload
    - download
    - upload_speed
    - download_speed

Additional information

• Link to documentation pull request: Add new sensor home-assistant.io#12966

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

[probot-home-assistant]

Hey there @kennedyshead, mind taking a look at this pull request as its been labeled with a integration (asuswrt) you are listed as a codeowner for? Thanks!

[timmo001]

I did try to add a unique_id, but couldn't find a good candidate. @kennedyshead since it's your library, do you know a way to get the router's mac address or serial number for example?

This can always be a future change however

[MartinHjelmare]

We try to avoid grouping values as attributes. Can we instead make one binary sensor per connected device with device class connectivity?

[timmo001]

Well we have device_tracker for that so I guess I'll remove the attributes

[MartinHjelmare]

Codeowner should approve too.

[kennedyshead]

This just might be a bad idea...
I will do some tests. There might be a way to build these sensors without doing extra calls?

[kennedyshead]

Nah! This will work fine for now.
There will be a 5s cache in aioasuswrt in the future I think... These routers are sensitive in how many commands that run.

btw: Yes I'm 100% sure we can get a unique id for the router if we want to.

[kennedyshead]

In short: 🐬

[MartinHjelmare]

Please extend the sensor tests to cover the diff. Ie set the "sensors" key in the config with "devices" when setting up the component with async_setup_component and patch the library appropriately.

[MartinHjelmare]

Please await hass.async_block_till_done() after setting up the component in the test and assert the state of the entities via the core state machine. We propably need to extend the mocking of the api methods to return appropriate data.

[MartinHjelmare]

Great!