title: Can not load "webpack", it is not registered! Perhaps you are missing some plugin?
body: <p>ERROR [preprocess]: Can not load "webpack", it is not registered!
  Perhaps you are missing some plugin?</p>
  
  <p>Webpack version:
  4.14.0</p>
  
  <p>Webpack Karma version:
  2.0.4</p>
  
  <p>Karma version:
  3.0.0</p>
  
  <p>Linux </p>
  
  <pre><code> module.exports = ( config ) =&gt; {
        config.set( {
          basePath: path.resolve( __dirname ),
          browsers: [ 'PhantomJS' ],
          files: [ {
            pattern: '../../../spec/**/*.spec.js',
            watch: true
          } ],
          preprocessors: {
            [ '../../../spec/**/*.spec.js' ]: [ 'webpack' ]
          },
          reporters: [ 'mocha' ],
          plugins: [
            'karma-webpack',
            'karma-mocha',
            'karma-phantomjs-launcher',
            'karma-mocha-reporter',
          ],
          webpack: {
            mode: 'development',
            target: 'web',
            module: {
              rules: [ {
                test: /\.js$/,
                exclude: /node_modules/,
                use: {
                  loader: 'babel-loader'
                }
              } ]
            },
            resolve: {
              extensions: [ '.js', '.jsx ' ],
              modules: [ 'node_modules', 'src' ],
            }
          },
          webpackMiddleware: {
            noInfo: true,
            stats: {
              chunks: false
            }
          },
        } )
      } 
  </code></pre>