Add an option to ignore postcss warnings

[NikolayMakhonin]

Description

I want to disable unnecessary postcss warning in the console, like this:

[vite:css] C:\projects\my-site\src\styles\mixins.pcss is empty

Suggested solution

I propose to add a new option similar to onwarn in rollup, in which it will be possible to filter postcss warnings. I think the warnings filter should be used here

Alternative

Put this comment into mixins.pcss file: /* The file is empty now */

Additional context

No response

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[sapphi-red]

This is possible by customLogger option.

import { createLogger, defineConfig } from 'vite';

const logger = createLogger();
const originalWarning = logger.warn;
logger.warn = (msg, options) => {
  if (msg.includes('vite:css') && msg.includes(' is empty')) return;
  originalWarning(msg, options);
};

export default defineConfig({
  customLogger: logger,
});

https://stackblitz.com/edit/vitejs-vite-mjupek?file=vite.config.js&terminal=dev

[bluwy]

I feel like customLogger here is the best option as we would have a single point to handle all warnings of a Vite app. It looks like the option isn't documented though, so we could also do that.