Use Your Favorite PostCSS-Plugins With Svelte

Svelte plugin for using PostCSS plugins in svelte components

Install

npm install --save-dev svelte-postcss

or

npm i -D headmad/svelte-postcss

Usage

// rollup.config.js

import svelte from 'rollup-plugin-svelte';
import postcss from 'svelte-postcss';
import globalsStyles from 'postcss-svelte-global-styles'
...

export default {
  ...
  plugins: [
    svelte({
      preprocess: [
        postcss([ globalStyles, ...])
      ],
      ...
    })
  ]
}

In exemple, all PostCSS plugins will be applied to each svelte-file separately.
If you whant appli PostCSS to all styles of project, you mast add next code

// rollup.config.js

import svelte from 'rollup-plugin-svelte';
import postcss from 'svelte-postcss';
import globalsStyles from 'postcss-svelte-global-styles'
import mqPacker from 'css-mqpacker'
...

export default {
  ...
  plugins: [
    svelte({
      preprocess: [
        postcss([ globalStyles ])
      ],
      ...
      css: async (css) => {
        await postcss([    mqPacker() ])
          .run(css.code)
          .then((output) => { css.code = output })
        css.write('public/build/bundle.css');
      },
      ...
    })
  ]
}

In exemple used plugins postcss-svelte-global-styles and css-mqpacker

Also

You can use other gonfig sources. Like exemple - section postcss in package.json

{
  ...
  "postcss": {
    "map": false,
    "plugins": {
      "postcss-svelte-global-styles": {},
      ...
    }
  }
}

Or postcss.config.js file

module.exports = {
  map: false,
  plugins: {
    'postcss-svelte-global-styles': {}
    }
  }
}

License

MIT