anchor.diff:    Developers typically have separate configurations for development, production, and test environments.
     All three have a lot of configuration in common.
   
  -  开发、生产、测试不同的环境通常会分开配置，但实际上这些配置也有很多地方是通用的。
  +  开发、生产、测试等不同的环境通常会分开配置，但实际上这些配置也有很多地方是通用的。
   
     Gather the common configuration in a file called `webpack.common.js`.
     我们可以把这些通用的配置收归到一个文件，命名为`webpack.common.js`。
  
positive.code:   But most `import` statements don't mention the extension at all.
    Tell Webpack to resolve extension-less file requests by looking for matching files with
    `.ts` extension or `.js` extension (for regular JavaScript files and pre-compiled TypeScript files).
    实际上大部分`import`语句都不带扩展名，我们可以告诉Webpack，在查找这些没有扩展名的文件时，自动加上`.ts`或者`.js`扩展名来匹配。
  +makeExample('webpack/ts/config/webpack.common.js', 'resolve', 'config/webpack.common.js')(format=".")
  
  .l-sub-section
  
negative.code:   The app will `import` dozens if not hundreds of JavaScript and TypeScript files.
    You could write `import` statements with explicit extensions like this example:
    
    如果你的应用程序只须`import`几十个JavaScript或TypeScript文件，而不是几百个，你可以在`import`语句里完整写上扩展名，如：
  
  .code-example
    code-example(language="typescript").
  