v2 includes runtimeChunk twice with optimization.runtimeChunk option in webpack v4 about webpack-flush-chunks HOT 9 CLOSED

optimization: {
        runtimeChunk: {
            name: 'bootstrap'
        },
        splitChunks: {
            chunks: 'initial',
            cacheGroups: {
                vendors: {
                    test: /[\\/]node_modules[\\/]/,
                    name: 'vendor'
                }
            }
        },
}

import { flatten, includes } from 'lodash';

function filesFromChunks(chunkNames, assets, checkChunkNames) {
  const hasChunk = entry => {
    const result = !!assets[entry];
    if (!result && checkChunkNames) {
      console.warn(`Unable to find ${entry} in Webpack chunks.`);
    }

    return result;
  };

  const entryToFiles = entry => assets[entry];

  return [].concat(...chunkNames.filter(hasChunk).map(entryToFiles));
}

export default function chunksMap(clientStats) {
  const publicPath = clientStats.publicPath.replace(/\/$/, '');
  const beforeAssets = filesFromChunks(['bootstrap', 'vendor'], clientStats.assetsByChunkName);
  const afterAssets = filesFromChunks(['main'], clientStats.assetsByChunkName);

  return function flushChunks(chunkNames) {
    const mainAssets = flatten(chunkNames.map(chunkName => clientStats.namedChunkGroups[chunkName].assets));
    const allNeededAssets = [...beforeAssets, ...mainAssets, ...afterAssets];

    const jsAssets = allNeededAssets
      .filter(asset => includes(asset, '.js'))
      .map(file => `<script type='${includes(file, '.map') ? 'application/json' : 'text/javascript'}' src='${publicPath}/${file}' defer></script>`)
      .join('\n');

    return {
      js: jsAssets,
    };
  };
}