Webpack + Express + EJS:错误:找不到模块"."

Question

我正在用webpack,typescript和ejs编写一个快速的Web应用程序.当遇到一个应该提供.ejs文件的路由时,我收到以下错误:

Error: Cannot find module "."
   at webpackMissingModule (/Users/max/Development/test/express-webpack/dist/server.js:20669:74)
   at new View (/Users/max/Development/test/express-webpack/dist/server.js:20669:152)
   at EventEmitter.render (/Users/max/Development/test/express-webpack/dist/server.js:18776:12)
   at ServerResponse.render (/Users/max/Development/test/express-webpack/dist/server.js:20479:7)
   at /Users/max/Development/test/express-webpack/dist/server.js:25508:7
   at Layer.handle [as handle_request] (/Users/max/Development/test/express-webpack/dist/server.js:4524:5)
   at next (/Users/max/Development/test/express-webpack/dist/server.js:4743:13)
   at Route.dispatch (/Users/max/Development/test/express-webpack/dist/server.js:4724:3)
   at Layer.handle [as handle_request] (/Users/max/Development/test/express-webpack/dist/server.js:4524:5)
   at /Users/max/Development/test/express-webpack/dist/server.js:4054:22

这是代码:

的package.json:

{
  "name": "express-webpack",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "awesome-typescript-loader": "^3.0.0-beta.18",
    "copy-webpack-plugin": "^4.0.1",
    "debug": "^2.6.0",
    "ejs": "^2.5.5",
    "express": "^4.14.0",
    "json-loader": "^0.5.4",
    "source-map-loader": "^0.1.6",
    "webpack": "^2.2.0-rc.3"
  }
}

webpack.config.js

var CopyWebpackPlugin = require('copy-webpack-plugin');

module.exports = {
    entry: __dirname + "/src/index.js",
    target: "node",
    output: {
        filename: "server.js",
        path: __dirname + "/dist"
    },

    // Enable sourcemaps for debugging webpack's output.
    devtool: "source-map",

    resolve: {
        // Add '.ts' and '.tsx' as resolvable extensions.
        extensions: [".webpack.js", ".web.js", ".ts", ".tsx", ".js"]
    },

    module: {
        rules: [
            // All files with a '.ts' or '.tsx' extension will be handled by 'awesome-typescript-loader'.
            { test: /\.tsx?$/, loader: "awesome-typescript-loader" },
            { test: /\.json$/, loader: 'json-loader' },

            // All output '.js' files will have any sourcemaps re-processed by 'source-map-loader'.
            { enforce: "pre", test: /\.js$/, loader: "source-map-loader" }
        ]
    },

    plugins: [
        new CopyWebpackPlugin([
            { from: 'src/views', to: 'views' }
        ])
    ],

    node: {
      fs: "empty"
    }
};

SRC/index.js

var express = require('express');

var app = express();
app.set("view engine", "ejs");
app.set("views", "./views");
app.get('/', function(req, res, next){
  res.render('index'); // <-- error originates here AFAIK
});
app.listen(8000);

意见/ index.ejs

hello world

复制步骤:

• 运行webpack以构建项目
• 使用启动服务器 node dist/server.js
• 访问 http://localhost:8000
• 期望看到index.ejs的内容,而不是高于堆栈跟踪

知道出了什么问题吗？

Answer 1

我深入研究了webpack生成的代码,我发现似乎有一个关于webpack的上下文解析评估的bug.有一个简单的表达式表达用于要求选定的视图引擎,但它无法解决这个问题.

要解决此问题,请在索引中编写

const ejs = require("ejs").__express;
const app = express();
app.set("view engine", "ejs");   
app.engine('.ejs', ejs);// <-- this does the trick

但是如果你想要一个明确的解决方案,请在webpack repo上打开一个问题.

Answer 2

添加 Cleiton 的答案，现在在调用 app.engine(string, callback) 时必须有一个回调函数

app.set('views', 'src/views');
app.set('view engine', 'ejs');
app.engine('ejs', require('ejs').__express); //<-- this