Adding a local plugin to a Vue CLI preset

chunksPlugin.js

// Local Plugin:
// https://cli.vuejs.org/guide/plugins-and-presets.html#project-local-plugin

// See also: 
// https://cli.vuejs.org/dev-guide/plugin-dev.html#modifying-webpack-config
module.exports = api => {
  const webpack = require('webpack')

  api.configureWebpack({
    plugins: [
      new webpack.optimize.LimitChunkCountPlugin({
        maxChunks: 1
      })
    ]
  })
  
  api.chainWebpack(config => {
    config.optimization.delete('splitChunks')
  })
}

generator.js

module.exports = api => {

  // https://cli.vuejs.org/dev-guide/plugin-dev.html#creating-new-templates
  api.render('./chunksPlugin.js')
  
  // We need to make cli aware of the local plugin by adding it to package.json
  // https://cli.vuejs.org/dev-guide/plugin-dev.html#extending-package
  api.extendPackage({
    vuePlugins: {
      service: ['chunksPlugin.js']
    }
  })
}

preset.json

{
  "useConfigFiles": true,
  "router": true,
  "plugins": {
   "@vue/cli-plugin-babel": {}, 
  }
}