`NO_COLOR` not an alias for `NODE_DISABLE_COLORS` in v18

[veganaize]

Version

v18.20.5

Platform

Linux archlinux 6.6.56-1-lts #1 SMP PREEMPT_DYNAMIC Thu, 10 Oct 2024 12:04:53 +0000 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

1. Download an appropriate v18 binary from: https://nodejs.org/download/release/v18.20.5/
2. Unpack it and navigate to the node executable.
3. From the terminal run: NO_COLOR=1 ./node
4. Inside the REPL enter: [1]
5. Press [ENTER] and verify the result prints the 1 in color.

How often does it reproduce? Is there a required condition?

The issue is consistent 100% of the time.

What is the expected behavior? Why is that the expected behavior?

The expected behavior is that NO_COLOR should be an alias for NODE_DISABLE_COLORS because that's what's stated in the documentation.

What do you see instead?

Currently, for v18 (still under LTS at the time of this writing), NO_COLOR only disables color for output outside of the REPL, not within it. NODE_DISABLE_COLORS disables colorized output both outside of the REPL and within it.

Additional information

The issue seems to have been corrected only for Node.js v19.0.0+

[richardlau]

Looks like this was introduced into v18.x by #48034 (backported to v18.x by #48684). The regression was fixed in later release lines by #51568.

@nodejs/lts Thoughts? Node.js 18 is in maintenance -- I'd normally be wary of changing anything output related but this appears to be a regression (in 18.17.0) and #51568 looks like a straightforward change that should only affect the REPL.

[jasnell]

I'd say it's worth fixing in v18