SxsnPC/node_modules/vue/packages/compiler-sfc/src/stylePlugins/trim.ts

import { PluginCreator } from 'postcss'

const trimPlugin: PluginCreator<{}> = () => {
  return {
    postcssPlugin: 'vue-sfc-trim',
    Once(root) {
      root.walk(({ type, raws }) => {
        if (type === 'rule' || type === 'atrule') {
          if (raws.before) raws.before = '\n'
          if ('after' in raws && raws.after) raws.after = '\n'
        }
      })
    }
  }
}

trimPlugin.postcss = true
export default trimPlugin