title: delete generated .js files (from .ts) in folder using webpack
body: <p>I am trying to delete all <code>.js</code> files with in a folder which are generated from <code>.ts</code> files (from tsc)  using <a href="https://www.npmjs.com/package/clean-webpack-plugin" rel="nofollow noreferrer">clean-webpack-plugin</a></p>
  
  <p>but it is not deleting specific files, it is deleting all files.</p>
  
  <pre><code>             new CleanWebpackPlugin(['app'],
                  {
                      root: path.resolve('.'),
                      verbose: true,
                      dry: false,
                      exclude: ['**/*.ts','**/*.html']
                  })
  </code></pre>
  
  <p>How can i solve this problem</p>
  
  <ol>
  <li><p>either do not generate .js from tsc just generate bundle.js from webpack</p></li>
  <li><p>delete only .js files and not .ts/.html/.css from a given folder </p></li>
  </ol>
  
  <p>I also want to delete the <code>build</code> folder, seems like I would have to go back to <code>gulp</code> for this</p>