这个插件可以在打包时替换文件中的字符串

var StringReplacePlugin = require("string-replace-webpack-plugin");

module: {
      loaders: [ // 或者是 rules 可能
         { 
            test: ......,
            loader: StringReplacePlugin.replace({
                replacements: [
                    {
                        pattern: 正则匹配式,
                        replacement: function (match, p1, offset, string) {
                            return 替换结果;
                        }
                    }
                ]})
            }
      ]
   },

plugins: [
    // an instance of the plugin must be present
    new StringReplacePlugin()
 ]