fix: respect NO_COLOR and TERM=dumb environment variables

[shaanmajid]

Fixes #763

Changes is_hidden() and drawable() to check term.features().colors_supported() instead of term.is_term(). The console crate's colors_supported() already checks for NO_COLOR and TERM=dumb, so this change makes indicatif respect those signals.

Test plan

Use the MRE from #763 with a path dependency:

indicatif = { path = "path/to/fix/branch/indicatif" }

script creates a pseudo-TTY so isatty() returns true. Grepping for 1b 5b (hex ESC[) detects ANSI escape sequences. With the fix, no output should appear when TERM=dumb or NO_COLOR=1.

# Normal TTY - escape sequences expected
script -q /dev/null ./target/release/mre 2>&1 | xxd | grep '1b 5b'
# Output: 00000050: ... 0d1b 5b32 4b ...  (ESC[2K present)

# With TERM=dumb - escape sequences should be suppressed
TERM=dumb script -q /dev/null ./target/release/mre 2>&1 | xxd | grep '1b 5b'
# No output expected

# With NO_COLOR=1 - escape sequences should be suppressed
NO_COLOR=1 script -q /dev/null ./target/release/mre 2>&1 | xxd | grep '1b 5b'
# No output expected

[djc]

I like it! @chris-laplante is there anything I'm missing here?

[chris-laplante]

I like it! @chris-laplante is there anything I'm missing here?

Looks nice and simple to me :)

[shaanmajid]

Thanks y'all :)

[j178]

Thanks! Any chance we could get a release for this?

[djc]

We can definitely do a release soon. There's one more potential fix I'd like to wait for (if it doesn't take too long).