jsbundling-rails + webpack + webpack-dev-server

dev_server_proxy.rb

require "rack/proxy"

module Webpack
  class DevServerProxy < Rack::Proxy
    def perform_request(env)
      if Rails.env.development? && env['PATH_INFO'].start_with?('/assets')
        env["HTTP_HOST"] = env["HTTP_X_FORWARDED_HOST"] = 'localhost'
        env["HTTP_X_FORWARDED_SERVER"] = 'localhost:3035'
        env["HTTP_PORT"] = env["HTTP_X_FORWARDED_PORT"] = '3035'
        env["HTTP_X_FORWARDED_PROTO"] = env["HTTP_X_FORWARDED_SCHEME"] = 'http'
        env["HTTPS"] = env["HTTP_X_FORWARDED_SSL"] = 'off'
        env["SCRIPT_NAME"] = ''

        super(env)
      else
        @app.call(env)
      end
    end
  end
end

webpack.config.js

const path = require('path');
const webpack = require('webpack');
const { VueLoaderPlugin } = require('vue-loader');

const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');
const RemoveEmptyScriptsPlugin = require('webpack-remove-empty-scripts');

const mode = process.env.NODE_ENV === 'development' ? 'development' : 'production';

module.exports = {
  mode,
  optimization: {
    minimizer: [
      new CssMinimizerPlugin(),
    ],
  },
  devServer: {
    https: false,
    host: 'localhost',
    port: 3035,
    hot: true,
    compress: true,
    headers: {
      'Access-Control-Allow-Origin': '*',
    },
    devMiddleware: {
      publicPath: '/assets/',
    },
    static: {
      directory: path.resolve(__dirname, 'app/assets/builds'),
    },
  },
  entry: {
    application: './app/frontend/packs/application.js',
  },
  output: {
    filename: '[name].js',
    sourceMapFilename: '[name].js.map',
    path: path.resolve(__dirname, 'app/assets/builds'),
    assetModuleFilename: 'images/[name][ext]',
  },
  plugins: [
    new webpack.optimize.LimitChunkCountPlugin({
      maxChunks: 1,
    }),
    new webpack.ProvidePlugin({
      $: 'jquery',
      jQuery: 'jquery',
      Popper: ['popper.js', 'default'],
    }),
    new VueLoaderPlugin(),
    new MiniCssExtractPlugin(),
    new RemoveEmptyScriptsPlugin(),
  ],
  module: {
    rules: [
      {
        test: /\.(js|ts)$/,
        exclude: /node_modules/,
        use: ['babel-loader'],
      },
      {
        test: /\.vue$/,
        loader: 'vue-loader',
      },
      {
        test: /\.s?[ac]ss$/i,
        use: [MiniCssExtractPlugin.loader, 'css-loader', 'sass-loader'],
      },
      {
        test: /\.(png|jpe?g|gif|eot|woff2|woff|ttf|svg|webp)$/i,
        type: 'asset/resource',
      },
    ],
  },
  resolve: {
    // Webpackで利用するときの設定
    alias: {
      vue$: 'vue/dist/vue.esm.js',
      '~': path.resolve(__dirname, 'app/frontend'),
    },
    extensions: ['*', '.js', '.vue', '.json', '.sass', '.scss', '.css'],
  },
};