vue.config.js

const path = require('path')
const fs = require('fs')
const PrerenderSPAPlugin = require('prerender-spa-plugin')

const PurgecssPlugin = require('purgecss-webpack-plugin');
const glob = require('glob-all');

module.exports = {
    lintOnSave: false,
    pwa: {
        name: 'My App',
        themeColor: '#4DBA87',
        msTileColor: '#000000',
        appleMobileWebAppCapable: 'yes',
        appleMobileWebAppStatusBarStyle: 'black',

        // configure the workbox plugin
        workboxPluginMode: 'InjectManifest',
        workboxOptions: {
            // swSrc is required in InjectManifest mode.
            swSrc: 'src/sw.js',
            // ...other Workbox options...
        }
    },
    configureWebpack(config) {
        if (process.env.NODE_ENV === 'production') {
            return {

                plugins: [
                    new PrerenderSPAPlugin({
                        // Required - The path to the webpack-outputted app to prerender.
                        staticDir: path.join(__dirname, 'dist'),
                        // Required - Routes to render.
                        routes: ['/', '/habit', '/setting'],
                    }),
                ],
            }
        };
    },

    chainWebpack: config => {
        config.optimization
          .clear('splitChunks')
          .splitChunks({
            cacheGroups: {
              vue: {
                name: 'vue',
                test: /[\\/]node_modules[\\/]vue[\\/]/,
                priority: 0,
                chunks: 'initial'
              },
              vendors: {
                name: 'chunk-vendors',
                test: /[\\/]node_modules[\\/]/,
                priority: -10,
                chunks: 'initial'
              },
              common: {
                name: 'chunk-common',
                minChunks: 2,
                priority: -20,
                chunks: 'initial',
                reuseExistingChunk: true
              }
            }
          })
    }
}