feat!: use the latest versions of css preprocessor loaders by default

docs/migrations/migrate-from-v4.md

@@ -80,10 +80,11 @@ No longer supports generating project with `node-sass`. It has been [deprecated]
 
 * `html-webpack-plugin` is upgraded from v3 to v5, and for webpack 4 users, v4 will be used. More details are available in the [release announcement of `html-webpack-plugin` v4](https://dev.to/jantimon/html-webpack-plugin-4-has-been-released-125d) and the [full changelog](https://github.com/jantimon/html-webpack-plugin/blob/master/CHANGELOG.md).
 * `sass-loader` v7 support is dropped. See the v8 breaking changes at its [changelog](https://github.com/webpack-contrib/sass-loader/blob/master/CHANGELOG.md#800-2019-08-29).
-* `postcss-loader` is upgraded from v3 to v4. Most notably, `PostCSS` options (`plugin` / `syntax` / `parser` / `stringifier`) are moved into the `postcssOptions` field. More details available at the [changelog](https://github.com/webpack-contrib/postcss-loader/blob/master/CHANGELOG.md#400-2020-09-07).
+* `postcss-loader` is upgraded from v3 to v5 (v4 for webpack 4 users). Most notably, `PostCSS` options (`plugin` / `syntax` / `parser` / `stringifier`) are moved into the `postcssOptions` field. More details available at the [changelog](https://github.com/webpack-contrib/postcss-loader/blob/master/CHANGELOG.md#400-2020-09-07).
 * `copy-webpack-plugin` is upgraded from v5 to v7 (v6 if you choose to stay at webpack 4). If you never customized its config through `config.plugin('copy')`, there should be no user-facing breaking changes. A full list of breaking changes is available at [`copy-webpack-plugin` v6.0.0 release](https://github.com/webpack-contrib/copy-webpack-plugin/releases/tag/v6.0.0) and [v7.0.0 release](https://github.com/webpack-contrib/copy-webpack-plugin/releases/tag/v7.0.0).
-* `file-loader` is upgraded from v4 to v6, and `url-loader` from v2 to v4. The `esModule` option is now turned on by default for non-Vue-2 projects. Full changelog available at [`file-loader` changelog](https://github.com/webpack-contrib/file-loader/blob/master/CHANGELOG.md) and [`url-loader` changelog](https://github.com/webpack-contrib/url-loader/blob/master/CHANGELOG.md)
+* `file-loader` is upgraded from v4 to v6, and `url-loader` from v2 to v4. The `esModule` option is now turned on by default for non-Vue-2 projects. Full changelog available at [`file-loader` changelog](https://github.com/webpack-contrib/file-loader/blob/master/CHANGELOG.md) and [`url-loader` changelog](https://github.com/webpack-contrib/url-loader/blob/master/CHANGELOG.md).
 * `terser-webpack-plugin` is upgraded from v2 to v5 (v4 if you choose to stay at webpack 4), using terser 5 and some there are some changes in the options format. See full details in its [changelog](https://github.com/webpack-contrib/terser-webpack-plugin/blob/master/CHANGELOG.md).
+* When creating new projects, the default `less-loader` is updated from [v5 to v8](https://github.com/webpack-contrib/less-loader/blob/master/CHANGELOG.md)(v7 for webpack 4 users); `less` from [v3 to v4](https://github.com/less/less.js/pull/3573); `sass-loader` from [v8 to v11](https://github.com/webpack-contrib/sass-loader/blob/master/CHANGELOG.md) (v10 for webpack 4 users); `stylus-loader` from [v3 to v5](https://github.com/webpack-contrib/stylus-loader/blob/master/CHANGELOG.md) (v4 for webpack 4 users).
 
 ### ESLint Plugin
 

packages/@vue/cli-plugin-webpack-4/generator.js

@@ -1,8 +1,10 @@
+const { semver } = require('@vue/cli-shared-utils')
+
 /** @type {import('@vue/cli').GeneratorPlugin} */
 module.exports = (api) => {
   api.extendPackage({
     devDependencies: {
-      'webpack': '^4.0.0'
+      webpack: '^4.0.0'
     },
     // Force resolutions is more reliable than module-alias
     // Yarn and PNPM 5.10+ support this feature
@@ -13,5 +15,36 @@ module.exports = (api) => {
     }
   })
 
-  // TODO: if uses sass, replace sass-loader@11 with sass-loader@10
+  api.extendPackage(
+    (pkg) => {
+      const oldDevDeps = pkg.devDependencies
+      const newDevDeps = {}
+      const unsupportedRanges = {
+        'less-loader': '>= 8.0.0',
+        'sass-loader': '>= 11.0.0',
+        'stylus-loader': '>= 5.0.0'
+      }
+      const maxSupportedRanges = {
+        'less-loader': '^7.3.0',
+        'sass-loader': '^10.1.1',
+        'stylus-loader': '^4.3.3'
+      }
+
+      for (const loader of ['less-loader', 'sass-loader', 'stylus-loader']) {
+        if (
+          oldDevDeps[loader] &&
+          semver.intersects(oldDevDeps[loader], unsupportedRanges[loader])
+        ) {
+          newDevDeps[loader] = maxSupportedRanges[loader]
+        }
+      }
+
+      const toMerge = { devDependencies: newDevDeps }
+
+      return toMerge
+    },
+    {
+      warnIncompatibleVersions: false
+    }
+  )
 }

packages/@vue/cli-plugin-webpack-4/index.js

@@ -10,7 +10,7 @@ const htmlWebpackPlugin4Path = path.dirname(require.resolve('html-webpack-plugin
 moduleAlias.addAlias('html-webpack-plugin', htmlWebpackPlugin4Path)
 
 /** @type {import('@vue/cli-service').ServicePlugin} */
-module.exports = (api, options) => {
+module.exports = (api, rootOptions) => {
   api.chainWebpack(config => {
     // webpack-4 alias is set for the webpack-dev-server
     // should also set for the injected client hmr code so as to avoid mismatch
@@ -49,6 +49,31 @@ module.exports = (api, options) => {
         .use({ ...require('pnp-webpack-plugin').topLevelLoader })
         .end()
 
+    // Use postcss-loader v7
+    const shadowMode = !!process.env.VUE_CLI_CSS_SHADOW_MODE
+    const isProd = process.env.NODE_ENV === 'production'
+    const { extract = isProd } = rootOptions.css || {}
+    const shouldExtract = extract !== false && !shadowMode
+    const needInlineMinification = isProd && !shouldExtract
+
+    const postcssLoaderPath = require.resolve('postcss-loader')
+
+    const langs = ['css', 'postcss', 'scss', 'sass', 'less', 'stylus']
+    const matches = ['vue-modules', 'vue', 'normal-modules', 'normal']
+
+    langs.forEach(lang =>
+      matches.forEach(match => {
+        const rule = config.module
+          .rule(lang)
+          .oneOf(match)
+
+        if (needInlineMinification) {
+          rule.use('cssnano').loader(postcssLoaderPath)
+        }
+        rule.use('postcss-loader').loader(postcssLoaderPath)
+      })
+    )
+
     if (!process.env.VUE_CLI_BUILD_TARGET || process.env.VUE_CLI_BUILD_TARGET === 'app') {
       const isLegacyBundle = process.env.VUE_CLI_MODERN_MODE && !process.env.VUE_CLI_MODERN_BUILD
       const publicDir = api.resolve('public')
@@ -103,7 +128,7 @@ module.exports = (api, options) => {
       config.optimization.minimizer('terser').init(
         (Plugin, [terserPluginOptions]) =>
           new TerserPluginV4({
-            sourceMap: options.productionSourceMap,
+            sourceMap: rootOptions.productionSourceMap,
             cache: true,
             ...terserPluginOptions
           })

packages/@vue/cli-plugin-webpack-4/package.json

@@ -23,11 +23,14 @@
     "access": "public"
   },
   "dependencies": {
+    "@vue/cli-shared-utils": "^5.0.0-alpha.4",
     "copy-webpack-plugin": "^6.4.1",
     "hash-sum": "^2.0.0",
     "html-webpack-plugin": "^4.5.1",
     "module-alias": "^2.2.2",
     "pnp-webpack-plugin": "^1.6.4",
+    "postcss": "^8.2.6",
+    "postcss-loader": "^4.2.0",
     "terser-webpack-plugin": "^4.2.3",
     "webpack": "^4.44.2"
   },

packages/@vue/cli-service/generator/index.js

@@ -39,19 +39,19 @@ module.exports = (api, options) => {
     const deps = {
       sass: {
         sass: '^1.32.7',
-        'sass-loader': '^10.1.0'
+        'sass-loader': '^11.0.1'
       },
       'dart-sass': {
         sass: '^1.32.7',
         'sass-loader': '^10.1.0'
       },
       less: {
-        'less': '^3.0.4',
-        'less-loader': '^5.0.0'
+        'less': '^4.0.0',
+        'less-loader': '^8.0.0'
       },
       stylus: {
         'stylus': '^0.54.8',
-        'stylus-loader': '^4.3.1'
+        'stylus-loader': '^5.0.0'
       }
     }