Test pymodbus

[janiversen]

Breaking change

Proposed change

This is a major rewrite of the low level modbus test harness (pymodbus library), tests now include:

• test of exceptions
• test of write
• test of modbus services.

This PR allows all modbus platforms to mock class modbusHub (our class) and thus avoid thinking about the pymodbus library. The PR is also helpful in the coming pymodbus upgrade (2.5.1).

Care have been used to ensure the tests do not use the internals of HA.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example entry for configuration.yaml:

# Example configuration.yaml

Just run pytest.

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

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.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[probot-home-assistant]

Hey there @adamchengtkc, @vzahradnik, mind taking a look at this pull request as its been labeled with an integration (modbus) you are listed as a codeowner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[janiversen]

I think this is not a modbus problem, let us try again to see if it is a fluke

[janiversen]

Changed mock(_logger) to caplog, as @MartinHjelmare suggested in #48829. I will update the other test (if needed) when providing PR´s for the rest of the outstanding issues. Target is to have most issues solved in 2021.5

[balloob]

This looks great! I had a few tiny comments.

[janiversen]

@balloob I think all your issues are solved (hopefully to your liking). Lets see if the checks are ok too.

[MartinHjelmare]

There's no public interface to the ModbusHub class yet, so then we should avoid accessing it in tests. Or is the plan to make it a public interface, ie public so that other integrations can use the hub instance directly?

[janiversen]

Just searched in tests/components and it seems all test suites access hass.data, so adding a get_domain function to hass might be a very good idea.

[MartinHjelmare]

Thanks!

[janiversen]

This is hopefully a glitch (I am not going to contact security as advised).