Github action setup initiative

[lee1043]

Copied from xcdat repo

[lee1043]

I guess having this .pre-commit-config.yaml should help some checks, at least for flake8. I copied the file from the xcdat repo.

@tomvothecoder @acordonez could you please see if this looks okay to you?

[lee1043]

Pre-commit test is failing because it expects json files to follow python style... Not sure how to tell pre-commit check to ignore *.json files..

[acordonez]

@lee1043 I found some info about flake8 in pre-commit hooks here: https://flake8.pycqa.org/en/latest/user/using-hooks.html. Might be able to add something like "exclude: *.json"?

[tomvothecoder]

black is a code formatter and isort is an import statement sorter.

I'm assuming the codebase did not integrate these QA tools previously. This means both of these tools (along with the other hooks) need to be run on the codebase and perform formatting as needed. Otherwise, pre-commit will most likely throw error(s).

There are a few options moving forward

1. Run pre-commit locally and format everything in this PR
   • This will produce a large diff regardless, so this might be the way to go
   • Local usage: pre-commit install and pre-commit run --all-files
2. Exclude these for now and open up another issue if you want to use these QA tools
3. Exclude them and don't use them (I personally prefer to use them)

[lee1043]

@tomvothecoder many thanks for the info. I think your guess is correct, that such tests have not been performed for the PMP codes. I think option 2 might be the most efficient way to move forward.

[tomvothecoder]

Same comment regarding running the tools and fixing issues.

mypy is an optional static type checker. flake8 and mypy may catch some existing issues that need to be fixed manually.

[tomvothecoder]

These are general QA hooks

[tomvothecoder]

Pre-commit test is failing because it expects json files to follow python style... Not sure how to tell pre-commit check to ignore *.json files..

pre-commit is failing due to the Trim Trailing Whitespace hook. https://github.com/PCMDI/pcmdi_metrics/runs/4094320066?check_suite_focus=true#step:4:70
I expect the other hooks to also fail based on my review comments.

Configuring the QA tools/hooks:

• setup.cfg from xcdat to configure flake8, mypy, and isort.
  https://github.com/XCDAT/xcdat/blob/main/setup.cfg
• pyproject.yoml from xcdat to configure black (doesn't support setup.cfg).
  https://github.com/XCDAT/xcdat/blob/main/pyproject.toml