Always pass FORCE_COLOR & NO_COLOR to the environment

[hashar]

The environment variables FORCE_COLOR and NO_COLORare a popular way to force or disable color output. An example usage is pytest being run under a CI system.

• ran the linter to address style issues (tox -e fix)
• wrote descriptive pull request text
• ensured there are test(s) validating the fix
• added news fragment in docs/changelog folder
• updated/extended the documentation

[gaborbernat]

https://no-color.org/ and FORCE_COLOR are the standard env vars. These app-specific ones don't get to be in the core.

[hashar]

I went with PY_COLORS a while ago which was even used by tox at some point ( #163 ). The other use case I had was for pytest but it has learned about NO_COLOR FORCE_COLOR since version 6.0.0 ( pytest-dev/pytest#7466 ).

def should_do_markup(file: TextIO) -> bool:
    if os.environ.get("PY_COLORS") == "1":
        return True
    if os.environ.get("PY_COLORS") == "0":
        return False
    if "NO_COLOR" in os.environ:
        return False
    if "FORCE_COLOR" in os.environ:
        return True
    return (
        hasattr(file, "isatty") and file.isatty() and os.environ.get("TERM") != "dumb"
    )

May I repurpose this pull request to add NO_COLOR and FORCE_COLOR to the environment variables passed by default? I find them handy.

[gaborbernat]

I don't think you need to add support for them. They should work today. Did you find the opposite?

[hashar]

NO_COLOR and FORCE_COLOR are only handled by the config cli parser to set the color flag. For the environments, they are not passed:

[testenv]
commands = python3 -c 'import os; print(os.environ.get("FORCE_COLOR"))'

$ FORCE_COLOR=1 tox -q
None

(same for NO_COLOR)

[gaborbernat]

If that doesn't work, a pull request is welcome. Just make sure to add the test and the changelog.

[hashar]

May you please reopen the pull request or should I send a new one? :)

[gaborbernat]

Don't forget to add test and changelog.

[hashar]

@gaborbernat I have repurposed the pull request to pass pass FORCE_COLOR and NO_COLOR instead of PY_COLORS.

[gaborbernat]

Yeah, but the CI is failing now that's blocking progress.

[hashar]

A test was failing under Windows OS.

I also fixed docs/changelog/3171.feature.rst which I forgot to update.

[gaborbernat]