title: webpack-bundle-analyzer shows webpack -p does not remove development dependency react-dom.development.js
body: <p>This is my webpack setup</p>
  
  <pre><code>const path = require('path');
  const HtmlWebpackPlugin = require('html-webpack-plugin');
  const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
  
  
  const SOURCE_DIR = './src';
  const HtmlWebpackPluginConfig = new HtmlWebpackPlugin({
    template: SOURCE_DIR + '/index.html',
    filename: 'index.html',
    inject: 'body'
  });
  
  module.exports = env =&gt; {
    console.log(`Environment Configs: ${JSON.stringify(env) || 'Default'}`);
    console.log(`
    Available Configs:
    --env.watch = true / false //for allow webpack to watch build
    `)
    let environment = env || {};
    const {
      watch,
      analyze,
    } = environment;
  
    const configedAnalyzer = new BundleAnalyzerPlugin({
      // Can be `server`, `static` or `disabled`.
      // In `server` mode analyzer will start HTTP server to show bundle report.
      // In `static` mode single HTML file with bundle report will be generated.
      // In `disabled` mode you can use this plugin to just generate Webpack Stats JSON file by setting `generateStatsFile` to `true`.
      analyzerMode: 'static',//was server
      // Host that will be used in `server` mode to start HTTP server.
      analyzerHost: '127.0.0.1',
      // Port that will be used in `server` mode to start HTTP server.
      analyzerPort: 9124,
      // Path to bundle report file that will be generated in `static` mode.
      // Relative to bundles output directory.
      reportFilename: './../report/bundle_anlaysis.html',
      // Module sizes to show in report by default.
      // Should be one of `stat`, `parsed` or `gzip`.
      // See "Definitions" section for more information.
      defaultSizes: 'stat',
      // Automatically open report in default browser
      openAnalyzer: Boolean(analyze),
      // If `true`, Webpack Stats JSON file will be generated in bundles output directory
      generateStatsFile: Boolean(analyze),
      // Name of Webpack Stats JSON file that will be generated if `generateStatsFile` is `true`.
      // Relative to bundles output directory.
      statsFilename: 'stats.json',
      // Options for `stats.toJson()` method.
      // For example you can exclude sources of your modules from stats file with `source: false` option.
      // See more options here: https://github.com/webpack/webpack/blob/webpack-1/lib/Stats.js#L21
      statsOptions: null,
      // Log level. Can be 'info', 'warn', 'error' or 'silent'.
      logLevel: 'info'
    });
  
    return {
      entry: SOURCE_DIR + '/index.js',
      output: {
        path: path.resolve(__dirname, "dist"),
        filename: 'bundle.js',
      },
      module: {
        rules: [
          {
            test: /\.js$/,
            exclude: /(node_modules)/,
            use: {
              loader: 'babel-loader',
              options: {
                presets: ['env', 'react']
              }
            }
          }
        ]
      },
      watchOptions: {
        aggregateTimeout: 300,
        poll: 1000
      },
      watch: Boolean(watch),
      plugins: [HtmlWebpackPluginConfig, configedAnalyzer], //
      devServer: {
        contentBase: path.join(__dirname, "dist"),
        compress: false,
        port: 9123,
      }
    };
  }
  </code></pre>
  
  <p>When I do <code>webpack -p</code> file size is a lot smaller but this react-dom.development.js take over almost 50% of the size, in my case 500ish KB out of 1.1ish MB.</p>
  
  <p>Report here:</p>
  
  <p><a href="https://i.stack.imgur.com/13v4O.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/13v4O.png" alt="enter image description here"></a></p>
  
  <p>To see a demo of the report and how it got run you can check <a href="https://github.com/adamchenwei/webpack-playground/tree/master/modularization/app" rel="nofollow noreferrer">this</a> repository.</p>
  
  <p>NOTE: even I add <code>NODE_ENV=production</code>, size is smaller but the development JavaScript file is still there!</p>