将 Webpack 与 Karma 一起使用会导致节点模块加载错误

Question

我正在尝试使用 Karma 运行我的 Jasmine 测试，但我相信某些应该加载的模块没有加载，这可能是依赖问题，但我的想法已经不多了。

karma.conf.js

var webpackConfig = require('./webpack.config.js');
webpackConfig.entry = {};

module.exports = function(config) {
  config.set({
    // base path that will be used to resolve all patterns (eg. files, exclude)
    basePath: '',
    // frameworks to use
    // available frameworks: https://npmjs.org/browse/keyword/karma-adapter
    frameworks: ['jasmine'],
    // list of files / patterns to load in the browser
    files: [
        { pattern: 'test-context.js'}
    ],
    // list of files to exclude
    exclude: [
    ],
    // preprocess matching files before serving them to the browser
    // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
    preprocessors: {
        'test-context.js': ['webpack']
    },
    webpack: webpackConfig,
    webpackMiddleware: {
      noInfo: true
    },
    // test results reporter to use
    // possible values: 'dots', 'progress'
    // available reporters: https://npmjs.org/browse/keyword/karma-reporter
    reporters: ['progress'],
    // web server port
    port: 9876,
    // enable / disable colors in the output (reporters and logs)
    colors: true,
    // level of logging
    // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
    logLevel: config.LOG_INFO,
    // enable / disable watching file and executing tests whenever any file changes
    autoWatch: true,
    // start these browsers
    // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
    browsers: ['Chrome'],
    // Continuous Integration mode
    // if true, Karma captures browsers, runs the tests and exits
    singleRun: false,
    // Concurrency level
    // how many browser should be started simultaneous
    concurrency: Infinity,
    debug: true
  })
}

webpack.config.js

var path = require('path');
var webpack = require('webpack');

module.exports = {
  entry: [
    'babel-polyfill',
    './index.js'
  ],
  output: {
      publicPath: '/',
      filename: 'main.js'
  },
  devtool: 'source-map',
  resolve: {
    extensions: ['', '.js', '.jsx']
  },
  module: {
    rules: [
      {
        test: /\.json$/,
        use: 'json-loader'
      }
    ],
    loaders: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/
      },
      {
        test: /\.json$/,
        loader: 'json-loader'
      }
    ]
  },
  node: {
    net: 'empty',
    tls: 'empty',
    //dns: 'empty',
    fs: 'empty'
  },
  externals: {
    //'crypto': 'crypto'
  },
  debug: true
};

package.json

{
  "name": "Web-Application",
  "version": "0.0.1",
  "description": "A web application",
  "engines": {
    "node": "5.9.1"
  },
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "tests": "karma start"
  },
  "dependencies": {
    "babel-preset-es2015": "^6.22.0",
    "babel-preset-react": "^6.23.0",
    "babel-register": "^6.23.0",
    "box-node-sdk": "^1.3.0",
    "ejs": "2.4.1",
    "express": "4.13.3",
    "node-libs-browser": "^2.0.0",
    "crypto-browserify": "^3.11.0"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/heroku/node-js-getting-started"
  },
  "keywords": [
    "node",
    "heroku",
    "express"
  ],
  "license": "MIT",
  "devDependencies": {
    "babel-cli": "^6.23.0",
    "babel-core": "^6.23.1",
    "babel-loader": "^v6.4.0",
    "babel-preset-env": "^1.2.0",
    "babel-preset-es2015": "^6.22.0",
    "express": "4.13.3",
    "jasmine-core": "^2.5.2",
    "json-loader": "^0.5.4",
    "karma": "^1.5.0",
    "karma-babel-preprocessor": "^6.0.1",
    "karma-chrome-launcher": "^2.0.0",
    "karma-jasmine": "^1.1.0",
    "karma-phantomjs2-launcher": "^0.5.0",
    "karma-webpack": "^2.0.2",
    "webpack": "^1.3.0",
    "webpack-dev-server": "1.10.1"
  }
}

我加了

node: {
    net: 'empty',
    tls: 'empty',
    //dns: 'empty',
    fs: 'empty'
  }, 

在代码中删除以前的依赖问题，但这可能只是修复了服务层，可能存在更深层次的依赖问题。

堆栈跟踪：

Git 源代码

https://github.com/noobiehacker/revaBoxWeb

感谢任何帮助或提示>

Answer 1

此示例是一个使用 express 的 Node.js 应用程序，它需要 Node.js 内置模块，例如 fs 或 net。但是您尝试使用 webpack 构建一个 Web 应用程序（默认目标是 web）并且在浏览器中这些模块不可用。 Webpack 告诉您无法解析这些模块，但您决定将它们清空，从而导致运行时错误。

要将express 与webpack 一起使用，您需要将target 配置为node，这样webpack 就不会触及内置模块。

target: 'node'

您还需要删除之前添加的node 配置。

我正在尝试使用 Karma 运行我的 Jasmine 测试

如上所述，您正在构建一个 Node.js 应用程序，但 Karma 是一个浏览器测试工具。它将无法运行您的代码。您的代码旨在由节点运行并由节点而不是浏览器测试。