Shouldn't be able to use --dir and -o together

[zachary95]

Hello,

I'm experiencing some issues by executing this command:

postcss components/**/*.css --dir 'wouldBeIgnoredAnyway' -o 'styles/app.css'

It compiles every source files well but output only contains the last compiled file.

I've checked the source code, that's because css() does fs.outputFile() which overwrite content every time one input get proceed.

Yet, I did a little fix on a fork available here : https://github.com/TheSuperFly/postcss-cli/tree/fix/overwritting. I'll create a pull request when a maintainer confirms that's a real issue and not a bad usage.

[michael-ciniawsky]

This is bad usage as implicit concatenation should be avoided, please use postcss-import instead with the --dir dest/ flag in case you have multiple dest CSS files (complete1.css, complete2.css, ... etc (src/*.css)).

[RyanZim]

That's poor usage; --dir and -o are supposed to be mutually exclusive. It is a bug that postcss-cli doesn't throw an error when you use them together.

[zachary95]

Ok, I see. So if you don't want this issue to be filled again, either we should trigger an error to avoid this behavior of overwritting or handle it nicely by handling multiple inputs when one output is expected, like sass's cli does transparently.

AHMA, option two is the way to go since I've been using postcss in a react (next.js) context where stylesheet belongs to components and should not require to edit global reference for being used, added or removed.

In my fork, I did a fs.append() on each compilation which could make a live reload system go crazy. But as an improvement, I can hold an certain amount of compiled sources in memory then commit at a certain moment to avoid memory leak.

Now you choose! 😄

[RyanZim]

Yeah, going to trigger an error here. Implicit concatenation isn't something I want, since I can't guarantee the order the files are appended to the output will always be consistent.

[michael-ciniawsky]

Yep, should throw. next.js (webpack) file structure is out-of-scope