node.js - 使用 webpack 转译 Node 服务器和 socket.io

Question

我尝试为使用 socket.io 的 Node 服务器使用 webpack。

我有一个简单的服务器:

var server = require('http').createServer();
var io = require('socket.io').listen(server);

io.on('connection', function(client) {
  console.log('new client');

  client.on('hello', function(data) {
    console.log('msg: ', data);
  });

  client.on('disconnect', function(){
    console.log('client disconnect');
  });
});

server.listen(3000);

还有我的 webpack.config.js

var config = {
  target: "node",
  entry: {
    server: ["server.js"]
  },
  module: {
    loaders: [
      {
        test: /\.(txt|json|osgjs|osgt|bin)$/,
        loader: "file?name=[path][name].[ext]"
      }
    ],
    noParse: ["ws"]
  }
  externals: ["ws"],
  output: {
    path: __dirname,
    filename: "[name].js"
  }
}

module.exports = config;

当我“编译”时我没有错误，只是一个警告:

> NODE_ENV=development BUILD_TARGET=server webpack --display-error-details

Hash: a692e23215bcd6caa05a
Version: webpack 1.13.2
Time: 672ms
                                       Asset     Size  Chunks             Chunk Names
              _/node_modules/mime-db/db.json   145 kB          [emitted]  
_/node_modules/socket.io-client/package.json  4.29 kB          [emitted]  
                                   server.js   572 kB       0  [emitted]  server
   [0] multi server 28 bytes {0} [built]
   [1] ./server.js 346 bytes {0} [built]
    + 88 hidden modules

WARNING in ../~/engine.io/lib/server.js
Critical dependencies:
74:43-65 the request of a dependency is an expression
 @ ../~/engine.io/lib/server.js 74:43-65

当我尝试启动我的服务器时:

fs.js:977
  return binding.fstat(fd);
                 ^

Error: EBADF: bad file descriptor, fstat
    at Error (native)
    at Object.fs.fstatSync (fs.js:977:18)
    at tryStatSync (fs.js:462:13)
    at fs.readFileSync (fs.js:510:12)
    at Object.<anonymous> (/Users/alexis/Documents/server.js:109:21)
    at __webpack_require__ (/Users/alexis/Documents/server.js:21:30)
    at Object.<anonymous> (/Users/alexis/Documents/server.js:56:34)
    at __webpack_require__ (/Users/alexis/Documents/server.js:21:30)
    at Object.<anonymous> (/Users/alexis/Documents/server.js:48:19)
    at __webpack_require__ (/Users/alexis/Documents/server.js:21:30)

我用:

• Node :6.7.0
• 网络包:1.13.2
• socket.io: 1.5.1

Answer 1

警告来自动态要求，例如:

const test = require('scripts/' + scriptName)

忽略它通常是安全的。 Webpack 尝试使用上下文模块来处理动态需求，它基本上是所有可能匹配动态需求的模块的表示。你可以在这里读更多关于它的内容: https://webpack.github.io/docs/context.html

关于这个错误，如果你不需要将 socket.io 打包到你的输出包中，你可以将它添加到 webpack 的外部配置中，webpack 会忽略它，但是你需要有一个 node_modules 文件夹解决方案中的 socket.io。

所以你的配置将是:

var config = {
  target: "node",
  entry: {
    server: ["server.js"]
  },
  module: {
    loaders: [
      {
        test: /\.(txt|json|osgjs|osgt|bin)$/,
        loader: "file?name=[path][name].[ext]"
      }
    ],
    noParse: ["ws"]
  }
  externals: ["ws", "socket.io"],
  output: {
    path: __dirname,
    filename: "[name].js"
  }
}

module.exports = config;

实际上最好不要在后端应用程序的 bundle 中包含 node_modules 依赖项，并且有一个 webpack 插件专门用于此目的: https://www.npmjs.com/package/webpack-node-externals

如果您想改用插件，您的配置将是(在安装 webpack-node-externals 之后):

var nodeExternals = require('webpack-node-externals')

var config = {
  target: "node",
  entry: {
    server: ["server.js"]
  },
  module: {
    loaders: [
      {
        test: /\.(txt|json|osgjs|osgt|bin)$/,
        loader: "file?name=[path][name].[ext]"
      }
    ],
    noParse: ["ws"]
  }
  externals: [nodeExternals()],
  output: {
    path: __dirname,
    filename: "[name].js"
  }
}

module.exports = config;