node.js - 使用 socket.io 和 webpack 构建 React 应用程序不起作用

Question

我这周一直在阅读有关此问题的内容，但是网络上的任何解决方案都不适用于我正在开发的项目。我正在使用 React 及其相关技术开发一个 Web 应用程序。为了进行编译过程，我使用了新版本的 webpack (v2.3.2)。我的服务器 webpack 配置与客户端 webpack 配置分开。一切都运行良好，直到我添加了 socket.io 以制作一些实时组件。应用网络中的所有解决方案，当我运行捆绑脚本时，我仍然收到以下警告:

WARNING in ./~/express/lib/view.js
80:29-41 Critical dependency: the request of a dependency is an expression

WARNING in ./~/socket.io/lib/index.js
109:11-32 Critical dependency: the request of a dependency is an expression

WARNING in ./~/engine.io/lib/server.js
115:15-37 Critical dependency: the request of a dependency is an expression

当我尝试启动我的项目时，出现以下错误:

return /*require.resolve*/(!(function webpackMissingModule() { var e = new Error("Cannot find module \".\""); e.code = 'MODULE_NOT_FOUND'; throw e; }()));
                                                                                                                                           ^

Error: Cannot find module "."
    at webpackMissingModule (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:357017:76)
at Server.serveClient   (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:357020:25)
    at new Server (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:356959:8)
    at Server (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:356951:41)
    at Object.<anonymous> (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:72569:33)
    at __webpack_require__ (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:20:30)
    at Object.<anonymous> (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:344445:18)
    at __webpack_require__ (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:20:30)
    at /Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:66:18
    at Object.<anonymous> (/Users/macpro/Documents/lisa_project/pos_lisa/built/server/index.js:69:10)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)

这是我的webpack.client.config.js

const ExtractTextPlugin = require('extract-text-webpack-plugin');
const path = require('path');
const webpack = require('webpack');

module.exports = {
  entry: ['babel-polyfill', path.join(__dirname, '../source/client.jsx')],
  output: {
    filename: 'app.js',
    path: path.join(__dirname, '../built/statics'),
  },
  module: {
    rules: [
      {
        test: /\.json$/,
        use: 'json-loader',
      },
      {
        test: /\.jsx?$/,
        exclude: /(node_modules)/,
        loader: 'babel-loader',
        query: {
          presets: ['es2016', 'es2017', 'react'],
          plugins: ['transform-es2015-modules-commonjs'],
        },
      },
      {
        test: /\.css$/,
        exclude: /(node_modules)/,
        loader: ExtractTextPlugin.extract({
          fallback: 'style-loader',
          use: 'css-loader?modules',
        }),
      },
      {
        test: /\.inline.svg$/,
        loader: 'babel-loader!react-svg-loader?' + JSON.stringify({
          svgo: {
            // svgo options
            plugins: [{removeTitle: false}],
            floatPrecision: 2
          }
        }),
      },
      {
        test: /\.jpe?g$|\.gif$|\.png$|^(?!.*\.inline\.svg$).*\.svg$/,
        loader: 'url-loader?limit=400000'
      },
    ],
    noParse: [ path.join(__dirname, '../node_modules/ws') ],
  },
  externals: [ path.join(__dirname, '../node_modules/ws'), path.join(__dirname, '../node_modules/socket.io') ],
  target: 'web',
  resolve: {
    extensions: ['.js', '.jsx', '.css', '.json'],
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env.BROWSER': true,
    }),
    new ExtractTextPlugin({
      filename: '../statics/styles.css',
      ignoreOrder: true,
    }),
  ],
  watch: true,
};

这是我的webpack.server.config.js

const ExtractTextPlugin = require('extract-text-webpack-plugin');
const path = require('path');
const webpack = require('webpack');

module.exports = {
  entry: ['babel-polyfill', path.join(__dirname, '../source/server.jsx')],
  output: {
    filename: 'index.js',
    path: path.join(__dirname, '../built/server'),
  },
  module: {
    rules: [
      {
        test: /\.json$/,
        use: 'json-loader',
      },
      {
        test: /\.jsx?$/,
        exclude: /(node_modules)/,
        loader: 'babel-loader',
        query: {
          presets: ['latest-minimal', 'react'],
        },
      },
      {
        test: /\.css$/,
        exclude: /(node_modules)/,
        loader: ExtractTextPlugin.extract({
          fallback: 'style-loader',
          use: 'css-loader?modules',
        }),
      },
      {
        test: /\.inline.svg$/,
        loaders: [ 'babel-loader',
          {
            loader: 'react-svg-loader',
            query: {
              svgo: {
                plugins: [{removeTitle: false}],
                floatPrecision: 2
              }
            }
          }
        ]
      },
      {
        test: /\.jpe?g$|\.gif$|\.png$|^(?!.*\.inline\.svg$).*\.svg$/,
        loader: 'url-loader?limit=400000'
      },
    ],
    noParse: [ path.join(__dirname, '../node_modules/ws') ],
  },
  externals: [ path.join(__dirname, '../node_modules/ws'), path.join(__dirname, '../node_modules/socket.io') ],
  target: 'node',
  resolve: {
    extensions: ['.js', '.jsx', '.css', '.json'],
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env.BROWSER': false,
    }),
    new ExtractTextPlugin({
      filename: '../statics/styles.css',
      ignoreOrder: true,
    }),
  ],
  watch: true,
};

还有我的server.jsx(重要部分)

import http from 'http';
import express from 'express';
import socketio from 'socket.io';

const lisaApp = express();
const server = http.createServer(lisaApp);
const io = socketio(server);

提前感谢您的帮助和解答

Answer 1

好吧，我找到了解决方案，也许对其他人有帮助。在使用 webpack 的服务器端配置中，我们必须读取 node_modules 内的目录列表并提供给外部，保留模块的“require”，因此我们必须将以下内容添加到服务器端配置中。 (仅服务器端，客户端webpack工作正常):

const fs = require('fs');

var nodeModules = {};
fs.readdirSync('node_modules')
  .filter(function(x) {
    return ['.bin'].indexOf(x) === -1;
  })
  .forEach(function(mod) {
    nodeModules[mod] = 'commonjs ' + mod;
  });

此代码必须位于 const webpack 和 module.exports 之间。在“module”对象之后，添加以下行:

externals: nodeModules,

希望这对某人有帮助。