webpack4系列之 【2. 踩坑--webpack 2.x升级至4.x】

╄→гoц情女王★ 提交于 2020-03-28 20:50:27

一.安装webpack-cli,webpack@4.26.1

1.npm install webpack-cli -D

2.npm install webpack@4.26.1 -D

二.踩坑

执行npm run dev报错

1./Users/lily/ForWork/forBMSys/bm-fe/node_modules/html-webpack-plugin/lib/compiler.js:81

var outputName = compilation.mainTemplate.applyPluginsWaterfall('asset-path', outputOptions.filename, {
^

TypeError: compilation.mainTemplate.applyPluginsWaterfall is not a function

 解决方案:1).npm install webpack-contrib/html-webpack-plugin -D 网上大多数是这个答案,但是我这里执行不通,每次都报错。暂时没有找到原因。

    2).npm i -–save-dev html-webpack-plugin@next 
2./Users/lily/ForWork/forBMSys/bm-fe/node_modules/webpack/lib/webpack.js:185

throw new RemovedPluginError(errorMessage);
^

Error: webpack.optimize.UglifyJsPlugin has been removed, please use config.optimization.minimize instead.

解决方案:

npm install --save-dev uglifyjs-webpack-pluginwebpack.dev.conf.js配置
var UglifyJsPlugin = require('uglifyjs-webpack-plugin')
optimization: {  minimizer: [    new UglifyJsPlugin({      exclude: /\.min\.js$/,      cache: true,      parallel: true, // 开启并行压缩,充分利用cpu      sourceMap: false,      extractComments: false, // 移除注释      uglifyOptions: {        compress: false      }    })  ]}

 3./Users/lily/ForWork/forBMSys/bm-fe/node_modules/webpack/lib/webpack.js:185

throw new RemovedPluginError(errorMessage);
^

Error: webpack.optimize.CommonsChunkPlugin has been removed, please use config.optimization.splitChunks instead.

 解决方案:

注释掉CommonsChunkPlugin,webpack4自带代码分割功能,如果想要覆盖默认设置,可以添加:

optimization: {  splitChunks: {    cacheGroups: {      commons: {  // 抽离自己写的公共代码        chunks: "async",  // async针对异步加载的chunk做切割,initial针对初始chunk,all针对所有chunk。        name: "common", // 打包后的文件名,任意命名        minChunks: 2,//最小引用2次        minSize: 30000 // 只要超出30000字节就生成一个新包      },      vendor: {   // 抽离第三方插件        test: /[\\/]node_modules[\\/]/, // 指定是node_modules下的第三方包        chunks: 'initial',        name: 'vendor',  // 打包后的文件名,任意命名        priority: 10 // 设置优先级,防止和自定义的公共代码提取时被覆盖,不进行打包      },    }  },  // runtimeChunk: true     // 持久缓存moduleID,ChunkID需要HashedModuleIdsPlugin等插件解决},

 注意:同时去掉 extract-text-webpack-plugin 插件的使用

4.cannot read property 'eslint' of undefined

解决方案:

1)网上查了很多,都让使用LoaderOptionsPlugin方案,但是我这边添加之后,并没有任何效果依然报错

plugins: [new webpack.LoaderOptionsPlugin({ options: {} }),],

2)升级eslint-loader,升级 eslint-loader to ^2.0.0. 于是有了第5个错

5.ERROR in ./src/index.js

Module build failed (from ./node_modules/eslint-loader/index.js):
Error: eslint-plugin-html error: It seems that eslint is not loaded. If you think it is a bug, please file a report at https://github.com/BenoitZugmeyer/eslint-plugin-html/issues

解决方案:

eslint4只支持eslint-plugin-html V3 ,把eslint-plugin-html升级即可解决

https://github.com/BenoitZugmeyer/eslint-plugin-html/issues/60

6.ERROR in ./src/components/views/remote-dispatch/remote-car-sku-options/view/RemoteCarSkuOptionsCreate.vue?vue&type=style&index=0&id=a8deb48e&lang=scss&scoped=true& (./node_modules/vue-loader/lib??vue-loader-options!./src/components/views/remote-dispatch/remote-car-sku-options/view/RemoteCarSkuOptionsCreate.vue?vue&type=style&index=0&id=a8deb48e&lang=scss&scoped=true&) 99:0

Module parse failed: Unexpected token (99:0)
You may need an appropriate loader to handle this file type.
|
|
> .remote {
| padding: 20px;
| margin-top: 25px;

解决方案:

添加了file-loader就可以了 

需要注意的是 MiniCssExtractPlugin.loader 和 style-loader 由于某种原因不能共存。

 7.代码运行的时候,报错,

error in ./src/components/views/workbench/designated-driving/view-customer/task-check/task-check.vue?vue&type=style&index=0&lang=css&

Syntax Error: NonErrorEmittedError: (Emitted value instead of an instance of Error) CssSyntaxError: /Users/lily/ForWork/forBMSys/bm-fe/src/components/views/workbench/designated-driving/view-customer/task-check/task-check.vue:1:1: Unknown word

> 1 | exports = module.exports = require("../../../../../../../node_modules/css-loader/lib/css-base.js")();
| ^
2 | // imports
3 |

@ ./node_modules/vue-style-loader!./node_modules/css-loader!./node_modules/vue-loader/lib/loaders/stylePostLoader.js!./node_modules/css-loader??ref--8-1!./node_modules/vue-loader/lib??vue-loader-options!./src/components/views/workbench/designated-driving/view-customer/task-check/task-check.vue?vue&type=style&index=0&lang=css& 4:14-348 13:3-17:5 14:22-356

网上查的资料,大概两种解决方案,1.css-loader,style-loader顺序错误 2.删除css,less配置 第一种已排除,实行第二种,可行。但是build的时候又会报第6个(上一条)错误

 

8.Error: Plugin could not be registered at 'html-webpack-plugin-after-emit'. Hook was not found.

BREAKING CHANGE: There need to exist a hook at 'this.hooks'. To create a compatibility layer for this hook, hook into 'this._pluginCompat'.
at Compilation.plugin (/Users/lily/ForWork/forBMSys/bm-fe/node_modules/tapable/lib/Tapable.js:69:9)
at Compilation.deprecated [as plugin] (internal/util.js:53:15)
at /Users/lily/ForWork/forBMSys/bm-fe/build/dev-server.js:38:15

解决方案:

场景:项目运行起来后,一旦做出更改,保存后,便会报出该错
原因:这个错误是html-webpack-plugin和webpack4兼容问题导致,更改html-webpack-plugin版本即可,3.0.4,3.0.6都可以,排除2.28.0,3.2.0,其他版本还没有尝试

---------webpack升级完成之后的分割线-----------

9.这是webpack升级为4.0之后,项目迭代需求时遇到的问题

node_modules/html-webpack-plugin/node_modules/toposort/index.js:29
throw new Error('Cyclic dependency: '+JSON.stringify(node))

google上查都说是html-webpack-plugin的issue,参考 https://github.com/jantimon/html-webpack-plugin/issues/870 ,

更新html-webpack-plugin版本 以及安装toposort 1.0.4版本 更新完之后貌似还是报错

后来在百度上查到一篇 说是webpack4打包vue2的bug https://blog.csdn.net/alanfancy/article/details/84023940

这才发现,原来是我webpack本地配置的HtmlWebpackPlugin没有设置chunksSortMode: 'none' 至此问题解决

三.优化

1.html-webpack-plugin

npm i --save-dev html-webpack-plugin@next

plugins:[

new HtmlWebpackPlugin({  filename: process.env.NODE_ENV === 'testing'    ? 'index.html'    : 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: 'none'}),]

2.mini-css-extract-plugin 拆分css

它与extract-text-webpack-plugin最大的区别是:它在code spliting的时候会将原先内联写在每一个 js chunk bundle的 css,单独拆成了一个个 css 文件

rules: [  {    test: /\.css$/,    use: [      process.env.NODE_ENV !== 'production'        ? 'vue-style-loader'        : MiniCssExtractPlugin.loader,      'css-loader'    ]  },  {    test: /\.less$/,    use: [      process.env.NODE_ENV !== 'production'        ? 'vue-style-loader'        : MiniCssExtractPlugin.loader,      'css-loader',      'less-loader'    ]  },...]

3.optimize-css-assets-webpack-plugin 压缩css 优化代码

optimization: {
  minimizer: [new OptimizeCSSAssetsPlugin()];
}

4.热更新速度 babel-plugin-dynamic-import-node

 1)首先在package.json中增加BABEL_ENV"dev": "BABEL_ENV=development webpack-dev-server XXXX"

  2)在.babelrc只能加入babel-plugin-dynamic-import-node这个plugins,并让它只有在development模式中才生效。

  {
    "env": {
      “development": {
        "plugins": ["dynamic-import-node"]
      }
    }  
  }

5.清除每次编译后dist目录重复文件 clean-webpack-plugin

 const CleanWebpackPlugin = require('clean-webpack-plugin');

plugins:[ new CleanWebpackPlugin(['dist']),//实例化,参数为目录]

6.代码分割splitChunks

optimization: {  splitChunks: {    cacheGroups: {      elementUI: {        name: "chunk-elementUI", // 单独将 elementUI 拆包        priority: 20, // 权重要大于 libs 和 app 不然会被打包进 libs 或者 app        test: /[\\/]node_modules[\\/]element-ui[\\/]/      },      libs: {        name: "chunk-libs",        test: /[\\/]node_modules[\\/]/,        priority: 10,        chunks: "initial" // 只打包初始时依赖的第三方      },      commons: {  // 抽离自己写的公共代码        chunks: "async",  // async针对异步加载的chunk做切割,initial针对初始chunk,all针对所有chunk。        name: "common", // 打包后的文件名,任意命名        test: /[\\/]src[\\/]components[\\/]pages/,        minChunks: 3,//最小引用2次        minSize: 30000 // 只要超出30000字节就生成一个新包      },    }  },  runtimeChunk: {    name: "manifest"  },  minimizer: [new OptimizeCSSAssetsPlugin()]}

7.externals分离第三方库,cdn引入第三方资源

1)index.html中,引入第三方类库 如:<script src="//cdn.bootcss.com/echarts/4.1.0/echarts.min.js"></script>

2) webpack.conf.js中配置externals 如

module.exports = {  ...  externals:{echarts: 'echarts'}  ...}

8.lodash按需加载

  点此查看我的另一篇笔记 

踩坑继续中,如果有人看到,欢迎随时交流----

 

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