vue.config.js

// const CSSLoaderResolver = require('@vue/cli-service/lib/webpack/CSSLoaderResolver')

// const langs = ['css', 'scss'] // I only care about these languages for now
// const isProd = process.env.NODE_ENV === 'production'
// const cssExtract = false
// const postCSS = true
// const sourceMap = true

// const userOptions = {
//   lintOnSave: false,
//   dll: true,
//   css: {
//     extract: cssExtract,
//     sourceMap: sourceMap
//   }
// }

// module.exports = Object.assign({}, userOptions, {
//   chainWebpack: config => {
//     // Customize CSS/SCSS loaders to handle relative paths
//     // Taking cues from @vue/cli-service/lib/config/css.js
//     const baseOptions = Object.assign({}, userOptions, {
//       sourceMap: sourceMap, // This was the missing option!
//       extract: isProd && userOptions.extract !== false,
//       minimize: isProd,
//       postcss: true
//     })

//     const resolver = new CSSLoaderResolver(baseOptions)

//     for (const lang of langs) {
//       // Remove existing rule
//       config.module.rules.delete(lang)

//       // Pull rule from default resolver for this language
//       const rule = resolver[lang]()

//       // Make an array of uses returned by the default resolver, in order
//       const newUses = []
//       for (const use of rule.use) {
//         newUses.push(use)

//         // Inject resolve-url-loader right after css-loader
//         if (use.loader === 'css-loader') {
//           newUses.push({
//             loader: 'resolve-url-loader',
//             options: {
//               sourceMap: sourceMap
//             }
//           })
//         }
//       }

//       // Set up a new rule for the language in this context
//       const context = config.module
//         .rule(lang)
//         .test(rule.test)
//         .include
//           .add(filepath => {
//             // Not ends with `.module.xxx`
//             return !/\.module\.[a-z]+$/.test(filepath)
//           })
//           .end()

//       // Now apply the new array of uses
//       newUses.forEach(use => {
//         context
//           .use(use.loader)
//             .loader(use.loader)
//             .options(use.options)
//       })
//     }
//   }
// })

// ----

module.exports = {
  lintOnSave: false,

  // https://cli.vuejs.org/guide/css.html#passing-options-to-pre-processor-loaders
  // making variable.scss available to all sass files, including .vue
  css: {
    sourceMap: true, // to enable resolve-url-loader
    loaderOptions: {
      sass: {
        data: '@import "@/assets/styles/variables.scss";'
      }
    }
  },


  // TODO: adicionar resolve-url-loader
  // @see https://forum.vuejs.org/t/using-resolve-url-loader-with-vue-cli-3-0-0/33036/3
  // @see https://github.com/mozilla-neutrino/webpack-chain/issues/28#issuecomment-334528021
  chainWebpack: config => {
    // descoberto via `vue inspect`
    // TODO: deve ser necessário adicionar as mesmas regras para oneOf('vue')
    config.module.rule('scss')
      .oneOf('normal')
        .use('resolve-url-loader')
        .loader('resolve-url-loader')
        .options({
          attempts: 1
        })
        .after('css-loader')

    config.module.rule('sass')
      .oneOf('normal')
        .use('resolve-url-loader')
        .loader('resolve-url-loader')
        .options({
          attempts: 1
        })
        .after('css-loader')
  }

};