Colorized output is not disabled when output is redirected

[software-dov]

Describe the bug
Redirecting nox output does not correctly determine that stdout is not a tty and adds color control codes to the output.

How to reproduce
Given a noxfile that defines some targets, e.g. unit tests, run
cd path/to/repo && python -m nox -s &> output-log.txt

Expected behavior
The contents of output-log.txt should be plain ASCII (or UTF-8) and not contain cursor control codes.

[dhermes]

TIL, neat!

# main.py
import sys


def main():
    print(f"STDIN : {sys.stdin.isatty()}")
    print(f"STDOUT: {sys.stdout.isatty()}")


if __name__ == "__main__":
    main()

yields

$ python main.py
STDIN : True
STDOUT: True
$ python main.py > is_tty.txt && /bin/cat is_tty.txt && rm -f is_tty.txt
STDIN : True
STDOUT: False
$ /usr/bin/touch stdin.txt && python main.py < stdin.txt && rm -f stdin.txt
STDIN : False
STDOUT: True

[dhermes]

AFAICT we only check if STDIN is a TTY and only do it in two places (1 and 2).

[software-dov]

Why does nox care if STDIN is a TTY?

[theacodes]

Probably just a mistake on my part. We should change it to stdout.

…

On Tue, Dec 3, 2019 at 10:42 AM Dov Shlachter ***@***.***> wrote: Why does nox care if STDIN is a TTY? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#266>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAB5I427PPGC3AYZRXF2HCLQW2SAFANCNFSM4JUO6G5Q> .