Using in non-tty environment giving errors

I am using this cli tool in lerna, which is not using tty channel to spawn child process for running npm scripts. In that case, the chalk command always faile with error code 1

Invalid style: THE_STRING_I_WANT_TO_LOG

Further investigate indicates if not using tty, this package is using getStdin from get-stdin to get the input, and trying to process all input as style. This is wrong as the data I want to print is also part of styles array, which is not a preset style, hence the error.

Run this in any non-tty process and you can reproduce the issue.

[Qix-]

Alright figured it out. To work around this, pass --no-stdin directly after chalk.

(You also need to add {stdio: 'inherit'} but that isn’t due to this library in any way).

In your repro, that looks like this:

execSync('npx chalk --no-stdin yellow "expect my colorful log 1"', {stdio: 'inherit'});

> chalk-cli-issue-11@1.0.0 log
> node index.js

expect my colorful log 1

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@sindresorhus I think meow is handling stdin all wrong, to be completely fair with you. --no-stdin is very much not a common unix pattern.

This is 1) undocumented as per our help docs, 2) not really a common unix-ey thing, 3) mishandles stdin if the option is accidentally omitted, clearly with a confusing effect. Not sure what the best course of action is aside from dropping meow and going with something a bit lighter weight.

I had also tagged this as “bug” but… I guess it’s not, if we’re going by how meow expects CLIs to work… not sure what to think about that.

[Qix-]

@sindresorhus

What is the intended behavior of this conditional? It’s the culprit here. There is no great way to detect if the user wants stdin consumption without having them specify it.

https://github.com/chalk/chalk-cli/blob/932d798cdce67d9e28f4b40fa9446a5ae0a8a52c/cli.js#L78

The fix here would be to allow passing - as the “input” or otherwise passing a new --stdin, -s flag that indicates stdin should be used as the input. My preference is the latter as it’s easier to discern between wanting stdin to parse and a literal - to display.