Support reading GitHub token from env var

[tplass-ias]

Proposed change

I would like to share my config.yaml and update scripts in a git repo, so I need a way to supply the GitHub token outside of config.yaml

This solution felt natural to me, but I would be willing to take a second pass utilizing a credentials file instead. (or any other preferred solution!)

Thanks for this great tool!

How to test the change

I tested manually by exporting the env var and successfully building a db.json with auto-pr pull

Checklist

• Tests have been added to verify that the new code works (if possible)
• Documentation has been updated to reflect changes
• CHANGELOG.md has been updated to reflect changes

[daniddelrio]

Thanks for the contribution! If you can also add a test case for it in the /test directory, that would be amazing 🙏 Something like mocking the env var APR_API_KEY in the run_cli util function and testing if the functionality still works afterwards would work

[tplass-ias]

hey @daniddelrio, I copy+modified test_create_files to work as an e2e test for using the env var for the api key. It already had a mock for create_github_client, which I used to validate the API key from the env var is used.

I had to adjust the feature implementation to play nice with pytest. Since the default value for the Credentials dataclass is set at import time, I needed to replace it with a function to return the value of the APR_API_KEY. This way the default value reflects the value of the env var during execution, and not just at script load time. I think this is inconsequential for actual usage, so I made the change.

Click's CliRunner's env injection doesn't seem to inject the env var at the right time, so I used pytest's monkeypatch feature instead.

Please let me know if you have any other feedback or suggestions :)

[daniddelrio]

LGTM, thanks again!