Angular 2 CLI 升级到最新版本，现在 ng serve 给我错误

Question

我在当前的 Angular 2 CLI 项目中升级到 1.0.0-beta.11-webpack.8，并更新了我的 angular-cli.json 以匹配升级后的预期属性命令行界面。当我运行 ng serve 时，出现此错误:

`Cannot read property 'length' of undefined
TypeError: Cannot read property 'length' of undefined
    at Object.getWebpackCommonConfig (/Applications/MAMP/htdocs/learnloop/node_modules/angular-cli/addon/ng2/models/webpack-build-common.ts:23:25)
    at new NgCliWebpackConfig (/Applications/MAMP/htdocs/learnloop/node_modules/angular-cli/addon/ng2/models/webpack-config.ts:13:30)
    at Class.exports.default.Task.extend.run (/Applications/MAMP/htdocs/learnloop/node_modules/angular-cli/addon/ng2/tasks/serve-webpack.ts:19:22)
    at /Applications/MAMP/htdocs/learnloop/node_modules/angular-cli/addon/ng2/commands/serve.ts:84:26
    at process._tickCallback (internal/process/next_tick.js:103:7)`

我为此纠结了一段时间，但在运行所有这些命令并让 Angular CLI 不处于损坏状态之后，我遇到了这个问题。这是我运行的命令:

`npm uninstall -g angular-cli
npm cache clean
npm install -g angular-cli@webpack
rm -rf node_modules dist tmp typings
npm install --save-dev angular-cli@webpack`

最后，这是我正在运行的节点、npm 和 Angular CLI 的版本:

节点 v6.4.0
NPM 3.10.3
angular-cli: 1.0.0-beta.11-webpack.8

这是我的 angular-cli.json:

`{
  "project": {
    "version": "1.0.0-beta.11-webpack.8",
    "name": "learnloop"
  },
  "apps": [
    {
      "main": "src/main.ts",
      "tsconfig": "src/tsconfig.json",
      "mobile": false,
      "prefix": "app",
      "root": "src",
      "styles": [
        "styles.scss"
      ]
    }
  ],
  "addons": [],
  "packages": [],
  "e2e": {
    "protractor": {
      "config": "config/protractor.conf.js"
    }
  },
  "test": {
    "karma": {
      "config": "config/karma.conf.js"
    }
  },
  "defaults": {
    "styleExt": "scss",
    "prefixInterfaces": false,
    "lazyRoutePrefix": "+"
  }
}`

我为冗长的文字道歉，但我想确保你们都拥有可能帮助解决此问题所需的一切。我在这里做错了什么？

Answer 1

我设法让它发挥作用。尝试将其粘贴到您的 angular-cli.json 中(相应地进行编辑):

{
  "project": {
    "version": "1.0.0-beta.11-webpack.8",
    "name": "<name-of-app>"
  },
  "apps": [
    {
      "root": "src",
      "outDir": "dist",
      "assets": "assets",
      "index": "index.html",
      "main": "main.ts",
      "test": "test.ts",
      "tsconfig": "tsconfig.json",
      "prefix": "app",
      "mobile": false,
      "styles": [
        "styles.scss"
      ],
      "scripts": [],
      "environments": {
        "source": "environments/environment.ts",
        "prod": "environments/environment.prod.ts",
        "dev": "environments/environment.dev.ts"
      }
    }
  ],
  "addons": [],
  "packages": [],
  "e2e": {
    "protractor": {
      "config": "./protractor.conf.js"
    }
  },
  "test": {
    "karma": {
      "config": "./karma.conf.js"
    }
  },
  "defaults": {
    "styleExt": "scss",
    "prefixInterfaces": false,
    "lazyRoutePrefix": "+"
  }
}

然后在根项目目录中键入 ng init。它会要求您替换一堆不同的文件或保留它们。文件之间存在一些细微差别，尤其是在 app.module.ts 内部，因此请确保先提交，因为文件结构和文件内部代码会有一些变化。