无法使用Webpack 2.2.0和webpack-dev-server 2.2.1进行HMR(热模块替换)css/scss

Question

版本

"extract-text-webpack-plugin":"^ 2.0.0-rc.2",

"webpack":"^ 2.2.0",

"webpack-dev-server":"^ 2.2.1"

问题

"extract-text-webpack-plugin":"^ 1.0.1",

"webpack":"^ 1.14.0",

"webpack-dev-server":"^ 1.16.2"

自从升级到版本2后不再能够HMR css/scss,更改样式会触发更改(请参阅下面的输出示例),但是我必须手动刷新页面以查看页面不会自动刷新的更改,如果我创建了更改scss文件后更改为js文件然后更改将反映为js更改触发HMR,其中还包括样式更改,但只更改样式而不更改js需要手动页面刷新.

任何想法,如果我配置了错误或我需要做什么让css/scss HMR工作？

我也在这里发布了这个问题:https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/384但不确定它是否是webpack-dev-server问题或者是extract-text-webpack -plugin问题或者只是我做过的事情.

命令运行:

npm run dev

"scripts": {
    "dev": "webpack-dev-server --hot --inline"
  }

升级前配置:

const webpack = require('webpack');
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');

const BUILD_DIR = path.resolve(__dirname, 'public');
const APP_DIR = path.resolve(__dirname, 'app');

let generateHtml = new HtmlWebpackPlugin({ title: 'My App' });
let extractCSS = new ExtractTextPlugin('styles/[name].css', { allChunks: true });

const config = {
  entry: APP_DIR + '/index.js',
  output: {
    path: BUILD_DIR,
    filename: 'bundle.js'
  },
  externals: {
    'cheerio': 'window',
    'react/lib/ExecutionEnvironment': true,
    'react/lib/ReactContext': true,
  },
  module : {
    loaders : [
      {
        test : /\.jsx?/,
        include : APP_DIR,
        loader : 'babel'
      },
      {
        test: /\.scss$/,
        loader: extractCSS.extract('style', 'css?modules=true!sass?sourceMap=true')
      }
    ]
  },
  plugins: [
    generateHtml,
    extractCSS
  ]
};

module.exports = config;

升级后配置:

const webpack = require('webpack');
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');

const BUILD_DIR = path.resolve(__dirname, 'public');
const APP_DIR = path.resolve(__dirname, 'app');

let generateHtml = new HtmlWebpackPlugin({ title: 'My App' });
let extractCSS = new ExtractTextPlugin({ filename: 'styles/[name].css', allChunks: true });

const config = {
  entry: APP_DIR + '/index.js',
  output: {
    path: BUILD_DIR,
    filename: 'bundle.js'
  },
  externals: {
    'cheerio': 'window',
    'react/lib/ExecutionEnvironment': true,
    'react/lib/ReactContext': true,
  },
  module : {
    loaders : [
      {
        test : /\.(js|jsx)?/,
        include : APP_DIR,
        loader : 'babel-loader'
      },
      {
        test: /\.scss$/,
        loader: extractCSS.extract({
          fallbackLoader: 'style-loader',
          loader: ['css-loader?modules', 'sass-loader']
        })
      }
    ]
  },
  plugins: [
    generateHtml,
    extractCSS
  ]
};

module.exports = config;

输出样本初始页面加载.

> webpack-dev-server --hot --inline

Project is running at http://localhost:8080/
webpack output is served from /
Hash: 0e873f689fcea2b7cee6
Version: webpack 2.2.0
Time: 3350ms
          Asset       Size  Chunks                    Chunk Names
      bundle.js     1.1 MB       0  [emitted]  [big]  main
styles/main.css  634 bytes       0  [emitted]         main
     index.html  223 bytes          [emitted]         
chunk    {0} bundle.js, styles/main.css (main) 1.03 MB [entry] [rendered]
   [19] ./~/react/react.js 56 bytes {0} [built]
   [45] ./~/redux/es/index.js 1.08 kB {0} [built]
  [106] ./~/react-redux/es/index.js 194 bytes {0} [built]
  [129] (webpack)/hot/emitter.js 77 bytes {0} [built]
  [130] ./app/index.js 938 bytes {0} [built]
  [131] (webpack)-dev-server/client?http://localhost:8080 4.66 kB {0} [built]
  [132] (webpack)/hot/dev-server.js 1.57 kB {0} [built]
  [139] ./app/containers/App.js 4.25 kB {0} [built]
  [178] ./~/react-dom/index.js 59 bytes {0} [built]
  [269] ./~/redux-thunk/lib/index.js 529 bytes {0} [built]
  [300] ./~/strip-ansi/index.js 161 bytes {0} [built]
  [305] ./~/url/url.js 23.3 kB {0} [built]
  [307] (webpack)-dev-server/client/socket.js 856 bytes {0} [built]
  [309] (webpack)/hot/log-apply-result.js 1.02 kB {0} [built]
  [310] multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server ./app/index.js 52 bytes {0} [built]
     + 296 hidden modules
Child html-webpack-plugin for "index.html":
    chunk    {0} index.html 541 kB [entry] [rendered]
        [0] ./~/lodash/lodash.js 540 kB {0} [built]
        [1] (webpack)/buildin/global.js 509 bytes {0} [built]
        [2] (webpack)/buildin/module.js 517 bytes {0} [built]
        [3] ./~/html-webpack-plugin/lib/loader.js!./~/html-webpack-plugin/default_index.ejs 540 bytes {0} [built]
Child extract-text-webpack-plugin:
    chunk    {0} extract-text-webpack-plugin-output-filename 1.77 kB [entry] [rendered]
        [0] ./~/css-loader/lib/css-base.js 1.51 kB {0} [built]
        [1] ./~/css-loader?modules!./~/sass-loader!./app/components/user/users.scss 267 bytes {0} [built]
Child extract-text-webpack-plugin:
    chunk    {0} extract-text-webpack-plugin-output-filename 1.81 kB [entry] [rendered]
        [0] ./~/css-loader/lib/css-base.js 1.51 kB {0} [built]
        [1] ./~/css-loader?modules!./~/sass-loader!./app/containers/app.scss 307 bytes {0} [built]
Child extract-text-webpack-plugin:
    chunk    {0} extract-text-webpack-plugin-output-filename 2.21 kB [entry] [rendered]
        [0] ./~/css-loader/lib/css-base.js 1.51 kB {0} [built]
        [1] ./~/css-loader?modules!./~/sass-loader!./app/components/navbar/navbar.scss 702 bytes {0} [built]
Child extract-text-webpack-plugin:
    chunk    {0} extract-text-webpack-plugin-output-filename 1.87 kB [entry] [rendered]
        [0] ./~/css-loader/lib/css-base.js 1.51 kB {0} [built]
        [1] ./~/css-loader?modules!./~/sass-loader!./app/components/common/common.scss 361 bytes {0} [built]
webpack: bundle is now VALID.

scss改变后的输出样本.

webpack: bundle is now INVALID.
Hash: f16b1beda9083db91735
Version: webpack 2.2.0
Time: 251ms
                               Asset       Size  Chunks                    Chunk Names
                           bundle.js     1.1 MB       0  [emitted]  [big]  main
0e873f689fcea2b7cee6.hot-update.json   35 bytes          [emitted]         
                     styles/main.css  626 bytes       0  [emitted]         main
chunk    {0} bundle.js, styles/main.css (main) 1.03 MB [entry] [rendered]
  [143] ./app/components/navbar/navbar.scss 181 bytes {0} [built]
     + 310 hidden modules
Child html-webpack-plugin for "index.html":
    chunk    {0} index.html 541 kB [entry]
         + 4 hidden modules
Child extract-text-webpack-plugin:
    chunk    {0} extract-text-webpack-plugin-output-filename 2.2 kB [entry] [rendered]
        [1] ./~/css-loader?modules!./~/sass-loader!./app/components/navbar/navbar.scss 694 bytes {0} [built]
         + 1 hidden modules
webpack: bundle is now VALID.

您可以看到main.css的大小已更改,但页面从未刷新,直到我按下f5

Answer 1

为了在使用 extract-text-webpack-plugin 时更好地控制 CSS HMR，请使用css-hot-loader

下面是我在规则集合中的使用代码示例

{ test: /\.css$/, use: ['css-hot-loader'].concat(ExtractTextPlugin.extract({ fallback: 'style-loader', use: 'css-loader' })) }