今年三月份入职以来，一直在做后台运营系统，其中重复性工作有很多，其中组件库就是一项。尽管现阶段有很多优秀的开源组件库，但是为了适应产品奇奇怪怪的需求，还是要手动实现一些组件。将其沉淀下来，积累一些自己东西。

概述：首先基于Vue-cli脚手架改装一个组件库的基本构建工具，它具备以下几点功能：

webpack3.0 升级 webpack4.0 => 更好地完成组件的开发以及打包工作；
支持sass => 加速组件样式开发；
支持导入markdown以及markdown样式自定义、以及code高亮；
自动配置路由。

2018年12月25日新增

highlight打包过大，缩减语言包；
jscpd检查重复代码。

将之前的v-highlight指令

// 这样加载了highlight所有的代码语言包，有300kb+
import hljs from 'highlight.js'
import 'highlight.js/styles/vs2015.css'

hljs.configure({ useBR: true })

Vue.directive('highlight',function (el) {
    let blocks = el.querySelectorAll('code')

    blocks.forEach(block => {
        hljs.highlightBlock(block)
    })
})

修改为

import hljs from 'highlight.js/lib/highlight';
import 'highlight.js/styles/github.css';
// 只加载Html、JavaScript
import javascript from 'highlight.js/lib/languages/javascript';
import xml from 'highlight.js/lib/languages/xml';

hljs.registerLanguage('javascript', javascript);
hljs.registerLanguage('xml', xml);
Vue.directive('highlight', function (el) {
        let blocks = el.querySelectorAll('code')
        Array.prototype.forEach.call(blocks, block => {
        hljs.highlightBlock(block)
    })
})

安装jscpd，npm i --save-dev jscpd，修改packjson.json

{
  ....
  "scripts": {
    "dev": "webpack-dev-server --inline --progress --config build/webpack.dev.conf.js",
    "start": "npm run dev",
    // 添加
    "check": "jscpd src",
    "build": "node build/build.js"
  },
  ...
}

运行结果

1. 实例

代码地址：UI-Library code

2. 安装流程

环境：win-64位、node-v8.12.0

安装

npm install --global vue-cli

安装vue-cli，之后创建一个ui-library的项目

vue init webpack ui-library

创建的项目的package.json中，webpack的版本为3.6.0

"webpack": "^3.6.0",
"webpack-bundle-analyzer": "^2.9.0",
"webpack-dev-server": "^2.9.1",
"webpack-merge": "^4.1.0"

为了升级webpack4.1.2，先把当前webpack以及其相关依赖uninstall

npm uninstall -D webpack webpack-bundle-analyzer webpack-dev-server webpack-merge
npm uninstall -D copy-webpack-plugin css-loader eslint-loader file-loader html-webpack-plugin url-loader  friendly-errors-webpack-plugin optimize-css-assets-webpack-plugin uglifyjs-webpack-plugin vue-loader

安装webpack4，由于webpack4依赖webpack-cli，所以也需要安装

npm install -D webpack webpack-cli webpack-bundle-analyzer webpack-dev-server webpack-merge
npm install -D copy-webpack-plugin css-loader eslint-loader file-loader html-webpack-plugin url-loader  friendly-errors-webpack-plugin optimize-css-assets-webpack-plugin uglifyjs-webpack-plugin vue-loader

手动替换extract-text-webpack-plugin插件 npm uninstall -D extract-text-webpack-plugin 替换为 npm install -D mini-css-extract-plugin

安装sass相关依赖 npm install -D node-sass sass-loader --save-dev

配置

首先配置webpack的mode，在webpack.dev.conf.js以及webpack.prod.conf.js中分别加上

const devWebpackConfig = merge(baseWebpackConfig, {
    mode: 'production',
    ...
})

const webpackConfig = merge(baseWebpackConfig, {
    mode: 'development',
    ...
})

配置webpack.base.conf.js文件

// 引入VueLoaderPlugin
const { VueLoaderPlugin } = require('vue-loader')
// 添加至
const devWebpackConfig = merge(baseWebpackConfig, {
    ...
    plugins: [
        new VueLoaderPlugin(),
        ...
    ]
})

配置webpack.prod.conf.js文件

需要删除

~~const ExtractTextPlugin = require('extract-text-webpack-plugin')~~

~~const UglifyJsPlugin = require('uglifyjs-webpack-plugin')~~

之后配置config项

const ExtractTextPlugin = require('extract-text-webpack-plugin')
const { VueLoaderPlugin } = require('vue-loader')

const webpackConfig = merge(baseWebpackConfig, {
    optimization: {
        splitChunks: {
          cacheGroups: {
            vendors: {
              test: /[\\/]node_modules[\\/]/,
              chunks: 'initial',
              name: 'vendors',
            },
            'async-vendors': {
              test: /[\\/]node_modules[\\/]/,
              minChunks: 2,
              chunks: 'async',
              name: 'async-vendors'
            }
          }
        },
        runtimeChunk: { name: 'runtime' }
    },
    plugins: [
        // 添加VueLoaderPlugin
        new VueLoaderPlugin(),
        ...
        // 引入MiniCssExtractPlugin
        new MiniCssExtractPlugin({
          filename: utils.assetsPath('css/[name].[contenthash:7].css')
        }),
        // Compress extracted CSS. We are using this plugin so that possible
        // duplicated CSS from different components can be deduped.
        new OptimizeCSSPlugin({
          cssProcessorOptions: config.build.productionSourceMap
            ? { safe: true, map: { inline: false } }
            : { safe: true }
        }),
        // see https://github.com/ampedandwired/html-webpack-plugin
        new HtmlWebpackPlugin({
          filename: config.build.index,
          template: 'index.html',
          inject: true,
          minify: {
            removeComments: true,
            collapseWhitespace: true,
            removeAttributeQuotes: true
            // more options:
            // https://github.com/kangax/html-minifier#options-quick-reference
          },
          // necessary to consistently work with multiple chunks via CommonsChunkPlugin
          chunksSortMode: 'dependency'
        }),
        // keep module.id stable when vendor modules does not change
        new webpack.HashedModuleIdsPlugin(),
        // copy custom static assets
        new CopyWebpackPlugin([
          {
            from: path.resolve(__dirname, '../static'),
            to: config.build.assetsSubDirectory,
            ignore: ['.*']
          }
        ])
    ]

修改utils.js

exports.cssLoaders = function(options) {
    options = options || {}

    // generate loader string to be used with extract text plugin
    function generateLoaders(loader, loaderOptions) {
        let loaders = []
        if (loader) {
            loaders = [{
                loader: loader + '-loader',
                options: Object.assign({}, loaderOptions, {
                    sourceMap: options.sourceMap
                })
            }]
        }

        if (options.extract) {
            let extractLoader = {
                loader: MiniCssExtractPlugin.loader,
                options: {}
            }

            return [extractLoader, 'css-loader'].concat(['postcss-loader'], loaders)
        } else {

            return ['vue-style-loader', 'css-loader'].concat(['postcss-loader'], loaders)
        }
    }

    return {
        css: generateLoaders(),
        postcss: generateLoaders(),
        less: generateLoaders('less'),
        sass: generateLoaders('sass', { indentedSyntax: true }),
        scss: generateLoaders('sass'),
        stylus: generateLoaders('stylus'),
        styl: generateLoaders('stylus')
    }
}

引入 sass-resources-loader 处理公共css文件

npm install -D sass-resources-loader --save-dev

修改上述 return 的值为

{
    ...
    scss: generateLoaders('sass').concat({
        loader: 'sass-resources-loader',
        options: {
            resources: path.resolve(__dirname, '../src/assets/styles/common.scss')
        }
    })
    ...
}

3. 支持导入markdown以及markdown样式自定义

由于vue-markdown-loader与vue-loader版本15有兼容性的问题，所以利用text-loader将Markdown文档导入并生成String，再编译为markdown文档。

首先npm install -D text-loader安装text-loader，用来引入*.md文件，再修改webpack.base.conf.js文件，添加text-loader

rules: [
    ...(config.dev.useEslint ? [createLintingRule()] : []),
    {
        test: /.md$/,
        loader: 'text-loader'
    },
    ...
]

在引入marked对导入的String进行编译

<template>
    <div class="markdown-body" v-html="compiledMarkdown" v-highlight></div>
</template>

import markdown from '../../README.md'
import marked from 'marked'

export default {
  computed: {
    markdowonText () {
      // 编译markdown
      return marked(markdown)
    }
  }
}

觉得markdown的样式有些丑，可以导入github-markdown-css

npm install -D github-markdown-css

对样式进行修改。如果markdown中存在着某些code，可以通过highlight进行高亮展示

npm install -D highlight

import hljs from 'highlight.js'
// 调整高亮code的样式
import 'highlight.js/styles/vs2015.css'

hljs.configure({ useBR: true })
// 注册一个directive用来添加code高亮
Vue.directive('highlight',function (el) {
    let blocks = el.querySelectorAll('code')

    blocks.forEach(block => {
        hljs.highlightBlock(block)
    })
})

4. 自动配置路由

利用require.context解析某个目录下的文件，将其生成Router的配置

const context = require.context('@/components/', true, /demo\.vue$/)
const componentRouters = context.keys().map(url => {
    const start = url.indexOf('/')
    const end = url.lastIndexOf('/')
    const name = url.substring(start + 1, end)
    const path = `/${name}`
    
    return {
        name,
        path,
        component: require(`@/components${path}/demo`).default
    }
})

export default new Router({
    routes: [
        {
            path: '/',
            name: 'mainPage',
            component: mainPage
        },
        
        ...componentRouters
        ]
    }
)

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