揭秘vue-cli3全局配置

创建项目

配置环境变量

  通过在package.json里的scripts配置项中添加--mode xxx来选择不同环境

  在项目根目录中新建.env, .env.production, .env.analyz等文件

  只有以 VUE_APP_ 开头的变量会被 webpack.DefinePlugin 静态嵌入到客户端侧的包中，代码中可以通过process.env.VUE_APP_BASE_API访问

  NODE_ENV 和 BASE_URL 是两个特殊变量，在代码中始终可用

.env serve默认的环境变量

NODE_ENV = 'development'
VUE_APP_BASE_API = 'https://demo.cn/api'
VUE_APP_SRC = 'https://wechat-timg.oss-cn-hangzhou.aliyuncs.com/demo'

.env.production build默认的环境变量

NODE_ENV = 'production'

VUE_APP_BASE_API = 'https://demo.com/api'
VUE_APP_SRC = 'https://img-wechat.oss-cn-hangzhou.aliyuncs.com/demo'

.env.analyz 用于webpack-bundle-analyzer打包分析

NODE_ENV = 'production'
IS_ANALYZ = 'analyz'

VUE_APP_BASE_API = 'https://demo.com/api'
VUE_APP_SRC = 'https://img-wechat.oss-cn-hangzhou.aliyuncs.com/demo'

  修改package.json

"scripts": {
  "serve": "vue-cli-service serve",
  "build": "vue-cli-service build",
  "analyz": "vue-cli-service build --mode analyz",
  "lint": "vue-cli-service lint"
}

配置vue.config.js

const IS_PROD = ['production', 'prod'].includes(process.env.NODE_ENV);

module.exports = {
  baseUrl: './', // 默认'/'，部署应用包时的基本 URL
  outputDir: process.env.outputDir || 'dist', // 'dist', 生产环境构建文件的目录
  assetsDir: '',  // 相对于outputDir的静态资源(js、css、img、fonts)目录
  lintOnSave: false,
  runtimeCompiler: true, // 是否使用包含运行时编译器的 Vue 构建版本
  productionSourceMap: false,  // 生产环境的 source map
  parallel: require('os').cpus().length > 1,
  pwa: {}
};

配置proxy跨域

const IS_PROD = ['production', 'prod'].includes(process.env.NODE_ENV);
module.exports = {
    devServer: {
        // overlay: {
        //   warnings: true,
        //   errors: true
        // },
        open: IS_PROD,
        host: '0.0.0.0',
        port: 8000,
        https: false,
        hotOnly: false,
        proxy: {
          '/api': {
            target: process.env.VUE_APP_BASE_API || 'http://127.0.0.1:8080',
            changeOrigin: true
          }
        }
    }
}

修复HMR(热更新)失效

module.exports = {
    chainWebpack: config => {
        // 修复HMR
        config.resolve.symlinks(true);
    }
}

添加别名

const path =  require('path');
const resolve = (dir) => path.join(__dirname, dir);
const IS_PROD = ['production', 'prod'].includes(process.env.NODE_ENV);

module.exports = {
    chainWebpack: config => {
        // 添加别名
        config.resolve.alias
          .set('@', resolve('src'))
          .set('assets', resolve('src/assets'))
          .set('components', resolve('src/components'))
          .set('layout', resolve('src/layout'))
          .set('base', resolve('src/base'))
          .set('static', resolve('src/static'));
    }
}

添加打包分析

const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;

module.exports = {
    chainWebpack: config => {
        // 打包分析
        if (process.env.IS_ANALYZ) {
          config.plugin('webpack-report')
            .use(BundleAnalyzerPlugin, [{
              analyzerMode: 'static',
            }]);
        }
    }
}

配置externals

  防止将某些 import 的包(package)打包到 bundle 中，而是在运行时(runtime)再去从外部获取这些扩展依赖

module.exports = {
    configureWebpack: config => {
        config.externals = {
          'vue': 'Vue',
          'element-ui': 'ELEMENT',
          'vue-router': 'VueRouter',
          'vuex': 'Vuex',
          'axios': 'axios'
        }
    }
}

去掉console.log

方法一：

const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
module.exports = {
    configureWebpack: config => {
        if (IS_PROD) {
            const plugins = [];
            plugins.push(
                new UglifyJsPlugin({
                    uglifyOptions: {
                        compress: {
                            warnings: false,
                            drop_console: true,
                            drop_debugger: false,
                            pure_funcs: ['console.log']//移除console
                        }
                    },
                    sourceMap: false,
                    parallel: true
                })
            );
            config.plugins = [
                ...config.plugins,
                ...plugins
            ];
        }
    }
}

方法二：使用babel-plugin-transform-remove-console插件

npm i --save-dev babel-plugin-transform-remove-console

在babel.config.js中配置

const plugins = [];
if(['production', 'prod'].includes(process.env.NODE_ENV)) {  
  plugins.push("transform-remove-console")
}

module.exports = {
  presets: [["@vue/app",{"useBuiltIns": "entry"}]],
  plugins: plugins
};

开启gzip压缩

npm i --save-dev compression-webpack-plugin

const CompressionWebpackPlugin = require('compression-webpack-plugin');
const productionGzipExtensions = /\.(js|css|json|txt|html|ico|svg)(\?.*)?$/i;

module.exports = {
    configureWebpack: config => {
        if (IS_PROD) {
            const plugins = [];
            plugins.push(
                new CompressionWebpackPlugin({
                    filename: '[path].gz[query]',
                    algorithm: 'gzip',
                    test: productionGzipExtensions,
                    threshold: 10240,
                    minRatio: 0.8
                })
            );
            config.plugins = [
                ...config.plugins,
                ...plugins
            ];
        }
    }
}

  还可以开启比gzip体验更好的Zopfli压缩详见https://webpack.js.org/plugins/compression-webpack-plugin

npm i --save-dev @gfx/zopfli brotli-webpack-plugin

const CompressionWebpackPlugin = require('compression-webpack-plugin');
const zopfli = require("@gfx/zopfli");
const BrotliPlugin = require("brotli-webpack-plugin");
const productionGzipExtensions = /\.(js|css|json|txt|html|ico|svg)(\?.*)?$/i;

module.exports = {
    configureWebpack: config => {
        if (IS_PROD) {
            const plugins = [];
            plugins.push(
                new CompressionWebpackPlugin({
                    algorithm(input, compressionOptions, callback) {
                      return zopfli.gzip(input, compressionOptions, callback);
                    },
                    compressionOptions: {
                      numiterations: 15
                    },
                    minRatio: 0.99,
                    test: productionGzipExtensions
                })
            );
            plugins.push(
                new BrotliPlugin({
                    test: productionGzipExtensions,
                    minRatio: 0.99
                })
            );
            config.plugins = [
                ...config.plugins,
                ...plugins
            ];
        }
    }
}

为sass提供全局样式，以及全局变量

  可以通过在main.js中Vue.prototype.src = process.env.VUE_APP_SRC;挂载环境变量中的配置信息，然后在js中使用src=process.env.VUEA​PPS​RC;挂载环境变量中的配置信息，然后在js中使用src访问。

  css中可以使用注入sass变量访问环境变量中的配置信息

module.exports = {
    css: {
        modules: false,
        extract: IS_PROD,
        sourceMap: false,
        loaderOptions: {
          sass: {
            // 向全局sass样式传入共享的全局变量
            data: `@import "~assets/scss/variables.scss";$src: "${process.env.VUE_APP_SRC}";`
          }
        }
    }
}

在scss中引用

.home {
    background: url($src + '/images/500.png');
}

添加IE兼容

npm i --save @babel/polyfill

  在main.js中添加

import '@babel/polyfill';

配置babel.config.js

const plugins = [];

module.exports = {
  presets: [["@vue/app",{"useBuiltIns": "entry"}]],
  plugins: plugins
};

搞定