Nuxt/packages/webpack/src/presets/pug.ts

import { WebpackConfigContext } from '../utils/config'

export function pug (ctx: WebpackConfigContext) {
  ctx.config.module.rules.push({
    test: /\.pug$/i,
    oneOf: [
      {
        resourceQuery: /^\?vue/i,
        use: [{
          loader: 'pug-plain-loader',
          options: ctx.options.build.loaders.pugPlain
        }]
      },
      {
        use: [
          'raw-loader',
          {
            loader: 'pug-plain-loader',
            options: ctx.options.build.loaders.pugPlain
          }
        ]
      }
    ]
  })
}