NO_COLOR implementation doesn't match the spec

[chocolateboy]

NO_COLOR is meant to disable color regardless of the value:

All command-line software which outputs text with ANSI color added should check for the presence of a NO_COLOR environment variable that, when present (regardless of its value), prevents the addition of ANSI color.

i.e. all of the following should disable color:

$ NO_COLOR=1 command  # ✔ 
$ NO_COLOR=0 command  # ✔
$ NO_COLOR= command   # x
$ NO_COLOR="" command # x

But the current implementation expects it to be truthy:

kleur/index.mjs

Line 10 in b08ad63

enabled: !NODE_DISABLE_COLORS && !NO_COLOR && TERM !== 'dumb' && (

[lukeed]

Ah, thanks! Even though it's in bold, I overlooked it 😆 Probably a cross-language thing? FOO=0 feels like it should always be an off-flag.

PR welcome, otherwise I probably won't get to it later today.

//cc @stramel since it might be a surprise to you too

[chocolateboy]

FOO=0 feels like it should always be an off-flag.

Yes, it's an annoying misfeature of the NO_COLOR spec (no other environment variables I'm aware of behave like it :-)

[lukeed]

How did you encounter this? Were you actually trying to do NO_COLOR= or NO_COLOR=0 in real usage?

[chocolateboy]

Trying to get FORCE_COLOR to not work like NO_COLOR in another library...