Question

我正在测试我的新设置，为此我正在编译服务器端脚本，如下所示：

import mongoose from 'mongoose';
import User from './models/UserSchema.jsx';

var connStr = 'mongodb://localhost:27017/mongoose-bcrypt-test';
mongoose.connect(connStr, function(err) {
    if (err) throw err;
    console.log('Successfully connected to MongoDB');
});

// create a user a new user
var testUser = new User({
    username: 'jmar777',
    password: 'Password123'
});

// save user to database
testUser.save(function(err) {
    if (err) throw err;

    // attempt to authenticate user
    User.getAuthenticated('jmar777', 'Password123', function(err, user, reason){
        if (err) throw err;

        // login was successful if we have a user
        if (user) {
            // handle login success
            console.log('login success');
            return;
        }

        // otherwise we can determine why we failed
        var reasons = User.failedLogin;
        switch (reason) {
            case reasons.NOT_FOUND:
            case reasons.PASSWORD_INCORRECT:
                // note: these cases are usually treated the same - don't tell
                // the user *why* the login failed, only that it did
                break;
            case reasons.MAX_ATTEMPTS:
                // send email or otherwise notify user that account is
                // temporarily locked
                break;
        }
    });
});

我正在使用webpack，具有以下配置：

module.exports = {
    entry: './testing.js',
    module: {
        loaders: [
            {
                exclude: /node_modules/,
                loader: 'babel',
                query: {
                    plugins: ['./build/babelRelayPlugin'],
                },
                test: /\.jsx?$/
            },
            {
                loader: 'node-loader',
                test: /\.node$/,
            },
            {
                loader: 'json-loader',
                test: /\.json$/,
            },
            {
                loader: 'raw-loader',
                test: /\.md/,
            },
        ]
    },
    output: {
        filename: 'app.js',
        path: __dirname
    },
    // resolve: {
    //     extensions: ["", ".js", ".jsx", ".node", ".webpack-loader.js", ".web-loader.js", ".loader.js"]
    // },
    // node: {
    //     fs: "empty",
    //     net: "empty",
    //     tls: "empty"
    // },
    target: "node"
}

编译代码时，我收到了以下警告：

WARNING in ./~/mongoose/lib/drivers/index.js
Critical dependencies:
8:11-74 the request of a dependency is an expression
 @ ./~/mongoose/lib/drivers/index.js 8:11-74

WARNING in ./~/bcrypt/~/bindings/bindings.js
Critical dependencies:
76:22-40 the request of a dependency is an expression
76:43-53 the request of a dependency is an expression
 @ ./~/bcrypt/~/bindings/bindings.js 76:22-40 76:43-53

WARNING in ./~/mongoose/~/bson/lib/bson/index.js
Critical dependencies:
20:16-29 the request of a dependency is an expression
44:18-31 the request of a dependency is an expression
71:19-32 the request of a dependency is an expression
 @ ./~/mongoose/~/bson/lib/bson/index.js 20:16-29 44:18-31 71:19-32

WARNING in ./~/mongodb/~/es6-promise/dist/es6-promise.js
Module not found: Error: Cannot resolve module 'vertx' in C:\bifrostApp\node_modules\mongodb\node_modules\es6-promise\dist
 @ ./~/mongodb/~/es6-promise/dist/es6-promise.js 132:20-30

WARNING in ./~/mongodb/~/mongodb-core/~/bson/lib/bson/index.js
Critical dependencies:
20:16-29 the request of a dependency is an expression
44:18-31 the request of a dependency is an expression
71:19-32 the request of a dependency is an expression
 @ ./~/mongodb/~/mongodb-core/~/bson/lib/bson/index.js 20:16-29 44:18-31 71:19-32

谷歌搜索后，我发现了这一点 https://github.com/webpack/webpack/issues/196 这似乎说它不是一个交易破坏者。仍然不完全确定它是否是。脚本编译时没有错误，只编译那些警告。生成其中一个警告的一段代码是：

/*!
 * ignore
 */

var driver;

if (typeof window === 'undefined') {
  driver = require(global.MONGOOSE_DRIVER_PATH || './node-mongodb-native');
} else {
  driver = require('./browser');
}

/*!
 * ignore
 */

module.exports = driver;

当我用节点运行脚本时，我收到此错误： Error: Cannot find module './node-mongodb-native'. at C:\bifrostApp\app.js:2165:42 at webpackContextResolve (C:\bifrostApp\app.js:2165:90) at webpackContext (C:\bifrostApp\app.js:2162:30) at Object.map../SPEC.md (C:\bifrostApp\app.js:2120:35) at __webpack_require__ (C:\bifrostApp\app.js:20:30) at Object.<anonymous> (C:\bifrostApp\app.js:832:17) at __webpack_require__ (C:\bifrostApp\app.js:20:30) at Object.<anonymous> (C:\bifrostApp\app.js:125:15) at __webpack_require__ (C:\bifrostApp\app.js:20:30) at Object.<anonymous> (C:\bifrostApp\app.js:112:19)

./ node-mongodb-native是一个目录，错误来自webpackContextResolve(req)，上述路径为req：

var map = {
    "./SPEC.md": 6,
    "./browser/ReadPreference": 7,
    "./browser/ReadPreference.js": 7,
    "./browser/binary": 8,
    "./browser/binary.js": 8,
    "./browser/index": 31,
    "./browser/index.js": 31,
    "./browser/objectid": 32,
    "./browser/objectid.js": 32,
    "./index": 4,
    "./index.js": 4,
    "./node-mongodb-native/ReadPreference": 33,
    "./node-mongodb-native/ReadPreference.js": 33,
    "./node-mongodb-native/binary": 134,
    "./node-mongodb-native/binary.js": 134,
    "./node-mongodb-native/collection": 135,
    "./node-mongodb-native/collection.js": 135,
    "./node-mongodb-native/connection": 225,
    "./node-mongodb-native/connection.js": 225,
    "./node-mongodb-native/index": 231,
    "./node-mongodb-native/index.js": 231,
    "./node-mongodb-native/objectid": 232,
    "./node-mongodb-native/objectid.js": 232
};
function webpackContext(req) {
    return __webpack_require__(webpackContextResolve(req));
};
function webpackContextResolve(req) {
    return map[req] || (function() { throw new Error("Cannot find module '" + req + "'.") }());
};

./node-mongodb-native文件夹的路径将不存在，这是有道理的，因为map中的文件将在稍后使用.call执行。我的问题是，为什么该文件夹最终会有一个文件路径列表？我该怎么做才能解决这个问题？我认为它是一个webpack问题，只是不太确定如何处理它。任何帮助将不胜感激。

Answer 1

我试图用node运行我的脚本。通过babel-node运行它来修复它。

Answer 2

这是一个webpack警告消息。请查看此http://webpack.github.io/docs/context.html#critical-dependencies以找到答案

Webpack`依赖的请求是一个表达式`

2 个答案: