title: Karma can't load webpack
body: <p>I'm getting this error;</p>
  
  <pre><code>16 07 2015 13:03:52.741:WARN [preprocess]: Can not load "webpack"!
     Error: Can not resolve circular dependency! (Resolving: preprocessor:webpack -&gt; webpackPlugin -&gt; preprocessor:webpack)
  </code></pre>
  
  <p>My karma.conf looks like;</p>
  
  <pre><code>var webpack = require('webpack');
  
  module.exports = function (config) {
    config.set({
      browsers: [ 'Chrome' ], //run in Chrome
      singleRun: true, //just run once by default
      frameworks: [ 'mocha' ], //use the mocha test framework
      files: [
        'tests.webpack.js' //just load this file
      ],
      preprocessors: {
        'tests.webpack.js': [ 'webpack', 'sourcemap' ] //preprocess with webpack and our sourcemap loader
      },
      reporters: [ 'dots' ], //report results in this format
      webpack: { //kind of a copy of your webpack config
        devtool: 'inline-source-map', //just do inline source maps instead of the default
        module: {
          loaders: [
            { test: /\.js$/, loader: 'babel-loader' }
          ]
        }
      },
      webpackServer: {
        noInfo: true //please don't spam the console when running in karma!
      }
    });
  };
  </code></pre>
  
  <p>and tests.webpack.js</p>
  
  <pre><code>var context = require.context('./src', true, /-test\.js$/); //make sure you have your directory and regex test set correctly!
  context.keys().forEach(context);
  </code></pre>
  
  <p>I do have karma and karma-webpack installed. </p>
  
  <p>Any ideas ? </p>