vue-element-admin项目打包后，生产环境再chrome浏览器下偶尔存在element-ui中的icon乱码

在将vue-element-admin或者vue-element-template打包发布到生产环境后，在chrome浏览器中刷新时，偶尔存在element-ui的icon出现乱码。F12查看乱码的icon元素，发现.el-icon-close:before { content: "□"}，同时html界面通过link标签引入的css文件都未被浏览器正常加载。非乱码情况下，icon元素也为.el-icon-close:before { content: "□"}，但是css文件是正常加载的。这就超出知识范畴了。百度，就决定是你了~~

其实，改问题再issues中提出有一段时间了，现有的解决方案是将dart-sass替换为node-sass。那就得继续用回node-sass，真让人头大~~

npm uninstall sass
npm install node-sass --save-dev

不想继续使用node-sass，只能想其他方法，终于在issues找到了解决方案。该方法是将src/styles/element-variables.scss文件下@import "~element-ui/packages/theme-chalk/src/index.scss全量引入修改为按需引入（除了icon.scss），如下：

// @import "~element-ui/packages/theme-chalk/src/index.scss
@import "~element-ui/packages/theme-chalk/src/pagination.scss";
@import "~element-ui/packages/theme-chalk/src/dialog.scss";
@import "~element-ui/packages/theme-chalk/src/autocomplete.scss";
@import "~element-ui/packages/theme-chalk/src/dropdown.scss";
@import "~element-ui/packages/theme-chalk/src/dropdown-menu.scss";
@import "~element-ui/packages/theme-chalk/src/dropdown-item.scss";
@import "~element-ui/packages/theme-chalk/src/menu.scss";
@import "~element-ui/packages/theme-chalk/src/submenu.scss";
@import "~element-ui/packages/theme-chalk/src/menu-item.scss";
@import "~element-ui/packages/theme-chalk/src/menu-item-group.scss";
@import "~element-ui/packages/theme-chalk/src/input.scss";
@import "~element-ui/packages/theme-chalk/src/input-number.scss";
@import "~element-ui/packages/theme-chalk/src/radio.scss";
@import "~element-ui/packages/theme-chalk/src/radio-group.scss";
@import "~element-ui/packages/theme-chalk/src/radio-button.scss";
@import "~element-ui/packages/theme-chalk/src/checkbox.scss";
@import "~element-ui/packages/theme-chalk/src/checkbox-button.scss";
@import "~element-ui/packages/theme-chalk/src/checkbox-group.scss";
@import "~element-ui/packages/theme-chalk/src/switch.scss";
@import "~element-ui/packages/theme-chalk/src/select.scss";
@import "~element-ui/packages/theme-chalk/src/button.scss";
@import "~element-ui/packages/theme-chalk/src/button-group.scss";
@import "~element-ui/packages/theme-chalk/src/table.scss";
@import "~element-ui/packages/theme-chalk/src/table-column.scss";
@import "~element-ui/packages/theme-chalk/src/date-picker.scss";
@import "~element-ui/packages/theme-chalk/src/time-select.scss";
@import "~element-ui/packages/theme-chalk/src/time-picker.scss";
@import "~element-ui/packages/theme-chalk/src/popover.scss";
@import "~element-ui/packages/theme-chalk/src/tooltip.scss";
@import "~element-ui/packages/theme-chalk/src/message-box.scss";
@import "~element-ui/packages/theme-chalk/src/breadcrumb.scss";
@import "~element-ui/packages/theme-chalk/src/breadcrumb-item.scss";
@import "~element-ui/packages/theme-chalk/src/form.scss";
@import "~element-ui/packages/theme-chalk/src/form-item.scss";
@import "~element-ui/packages/theme-chalk/src/tabs.scss";
@import "~element-ui/packages/theme-chalk/src/tab-pane.scss";
@import "~element-ui/packages/theme-chalk/src/tag.scss";
@import "~element-ui/packages/theme-chalk/src/tree.scss";
@import "~element-ui/packages/theme-chalk/src/alert.scss";
@import "~element-ui/packages/theme-chalk/src/notification.scss";
@import "~element-ui/packages/theme-chalk/src/slider.scss";
@import "~element-ui/packages/theme-chalk/src/loading.scss";
@import "~element-ui/packages/theme-chalk/src/row.scss";
@import "~element-ui/packages/theme-chalk/src/col.scss";
@import "~element-ui/packages/theme-chalk/src/upload.scss";
@import "~element-ui/packages/theme-chalk/src/progress.scss";
@import "~element-ui/packages/theme-chalk/src/spinner.scss";
@import "~element-ui/packages/theme-chalk/src/message.scss";
@import "~element-ui/packages/theme-chalk/src/badge.scss";
@import "~element-ui/packages/theme-chalk/src/card.scss";
@import "~element-ui/packages/theme-chalk/src/rate.scss";
@import "~element-ui/packages/theme-chalk/src/steps.scss";
@import "~element-ui/packages/theme-chalk/src/step.scss";
@import "~element-ui/packages/theme-chalk/src/carousel.scss";
@import "~element-ui/packages/theme-chalk/src/scrollbar.scss";
@import "~element-ui/packages/theme-chalk/src/carousel-item.scss";
@import "~element-ui/packages/theme-chalk/src/collapse.scss";
@import "~element-ui/packages/theme-chalk/src/collapse-item.scss";
@import "~element-ui/packages/theme-chalk/src/cascader.scss";
@import "~element-ui/packages/theme-chalk/src/color-picker.scss";
@import "~element-ui/packages/theme-chalk/src/transfer.scss";
@import "~element-ui/packages/theme-chalk/src/container.scss";
@import "~element-ui/packages/theme-chalk/src/header.scss";
@import "~element-ui/packages/theme-chalk/src/aside.scss";
@import "~element-ui/packages/theme-chalk/src/main.scss";
@import "~element-ui/packages/theme-chalk/src/footer.scss";
@import "~element-ui/packages/theme-chalk/src/timeline.scss";
@import "~element-ui/packages/theme-chalk/src/timeline-item.scss";
@import "~element-ui/packages/theme-chalk/src/link.scss";
@import "~element-ui/packages/theme-chalk/src/divider.scss";
@import "~element-ui/packages/theme-chalk/src/image.scss";
@import "~element-ui/packages/theme-chalk/src/calendar.scss";
@import "~element-ui/packages/theme-chalk/src/backtop.scss";
@import "~element-ui/packages/theme-chalk/src/infinite-scroll.scss";
@import "~element-ui/packages/theme-chalk/src/page-header.scss";
@import "~element-ui/packages/theme-chalk/src/cascader-panel.scss";
@import "~element-ui/packages/theme-chalk/src/avatar.scss";
@import "~element-ui/packages/theme-chalk/src/drawer.scss";
@import "~element-ui/packages/theme-chalk/src/popconfirm.scss";

替换后再次build发布到生产环境，app.xxxxxxxx.css不会再引入element-ui中的icon部分，只有element-ui本身的.el-icon-plus:before { content: "\e6d9";}，也就不存在icon乱码的问题了。

原理分析

• 为什么浏览器会不加载link的css文件
• 为什么当成功加载css文件时不乱码，未加载css文件时会乱码

上述两个问题一直没有找到答案，只能当做浏览器自身问题了（锅来~）。而当成功加载css文件时，html中打包生成的js函数应该有dart-sass解析部分，因此能够正常显示icon（不明所以猜想）。其中，vue-element-admin源码是采用dart-sass编译sass，而element-ui目前还是采用node-sass编译sass。两者可能存在冲突。上述的解决思路其实就是vue-element-admin自定义element-ui全局样式时，不引人icon相关部分，直接使用element-ui自身的icon变量。

2023-02-06更新

更优雅的解决方案

使用css-unicode-loader插件。

npm install -D css-unicode-loader

修改项目配置

 
// vue.config.js
module.exports = {
  configureWebpack: config => {
    config.module.rules.filter(rule => {
      return rule.test.toString().indexOf("scss") !== -1;
    })
      .forEach(rule => {
        rule.oneOf.forEach(oneOfRule => {
          oneOfRule.use.splice(oneOfRule.use.indexOf(require.resolve('sass-loader')), 0,
          	{ loader: require.resolve("css-unicode-loader")})
        })
      })
    }
}

原因分析

dartSass编译时，将icon转换成unicode的时候变成了乱码。