Fix --no-color not working

[teatwig]

I wanted to try out the new --color/--no-color options in Elixir 1.18.2 and disabling color doesn't work.

If I create the following file test.exs

IO.puts(IO.ANSI.format([:bright, "test message", :reset]))

and run it from my color enabled terminal it correctly displays in bright text.

If I run it with elixir --no-color test.exs it still prints it with bright text.

After applying the patch in this PR it prints correctly without any ANSI color escape sequences.

This seems to be an error when the changes introduced in 786f3ce where refectored: 2c1a836#diff-78a6fd95d2c5f4d0c0a5414b1393fc082ac242d2f70a665abe06f5e571da557d

[teatwig]

I was thinking about adding some tests to lib/elixir/test/elixir/kernel/cli_test.exs but I wasn't sure if it'd make more sense to create a new module for testing ANSI format or to add a test to one of the existing ones.

[josevalim]

Yes, that was a silly mistake. Thank you for the fix.

Regarding tests, those are hard to test in practice when shelling out, exactly the --no-color, because the default when shelling out is --no-color. :( And on the other cases, the computer may not have ansi enabled.

[josevalim]

💚 💙 💜 💛 ❤️

[teatwig]

Yeah that makes sense.
My idea would've been to simply test the output of evaluating IO.ANSI.enabled?/0 or alternatively inspecting the text to assert whether it has any escape sequences in it.

Something like elixir --color --eval 'IO.puts(IO.ANSI.enabled?())' should always return true.

But it's probably not super necessary :D

[josevalim]

Yeah, that would work for --color but it wouldn't test --no-color unfortunately as it would be false anyways! :(