测试期间导入scss文件失败

Question

我正在尝试在Vue组件中导入scss文件：

<style lang="scss">
  @import "./assets/styles/App.scss";
</style>

它在开发和生产版本（npm run dev，npm run build）上运行良好，但是在测试（Invalid CSS after "...load the styles": expected 1 selector or at-rule, was "var content = requi"）期间失败（npm test）。我正在使用业力作为跑步者。

我的配置： webpack.test.conf

'use strict'
// This is the webpack config used for unit tests.

const utils = require('./utils')
const webpack = require('webpack')
const merge = require('webpack-merge')
const baseWebpackConfig = require('./webpack.base.conf')

const webpackConfig = merge(baseWebpackConfig, {
  // use inline sourcemap for karma-sourcemap-loader
  module: {
    rules: utils.styleLoaders({ usePostCSS: true })
  },
  devtool: '#inline-source-map',
  resolveLoader: {
    alias: {
      'scss-loader': 'sass-loader'
    }
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env': require('../config/test.env')
    })
  ]
})

// no need for app entry during tests
delete webpackConfig.entry

module.exports = webpackConfig

webpack.base.conf

[...]
{
   test: /\.scss$/,
   use: [
     'vue-style-loader',
     'css-loader',
     'sass-loader'
   ]
 }
[...]

karma.conf.js

const webpackConfig = require('../../build/webpack.test.conf');

module.exports = function karmaConfig(config) {
  config.set({
    browsers: ['ChromeHeadless'],
    frameworks: ['mocha', 'sinon-chai'],
    reporters: ['spec', 'coverage'],
    files: ['./index.js'],
    preprocessors: {
      './index.js': ['webpack', 'sourcemap'],
    },
    webpack: webpackConfig,
    webpackMiddleware: {
      noInfo: true,
    },
    coverageReporter: {
      dir: './coverage',
      reporters: [
        { type: 'lcov', subdir: '.' },
        { type: 'text-summary' },
      ],
    },
  });
};

utils.js

exports.cssLoaders = function (options) {
  options = options || {}

  const cssLoader = {
    loader: 'css-loader',
    options: {
      sourceMap: options.sourceMap
    }
  }

  const postcssLoader = {
    loader: 'postcss-loader',
    options: {
      sourceMap: options.sourceMap
    }
  }

  // generate loader string to be used with extract text plugin
  function generateLoaders (loader, loaderOptions) {
    const loaders = options.usePostCSS ? [cssLoader, postcssLoader] : [cssLoader]

    if (loader) {
      loaders.push({
        loader: loader + '-loader',
        options: Object.assign({}, loaderOptions, {
          sourceMap: options.sourceMap
        })
      })
    }

    // Extract CSS when that option is specified
    // (which is the case during production build)
    if (options.extract) {
      return ExtractTextPlugin.extract({
        use: loaders,
        fallback: 'vue-style-loader'
      })
    } else {
      return ['vue-style-loader'].concat(loaders)
    }
  }

  // https://vue-loader.vuejs.org/en/configurations/extract-css.html
  return {
    css: generateLoaders(),
    postcss: generateLoaders(),
    less: generateLoaders('less'),
    sass: generateLoaders('sass', { indentedSyntax: true }),
    scss: generateLoaders('sass'),
    stylus: generateLoaders('stylus'),
    styl: generateLoaders('stylus')
  }

在我尝试导入scss文件之前，它工作正常（使用lang="scss"）。

我在这里想念的是什么？