fix: css content (v2)

packages/playground/css-codesplit/__tests__/css-codesplit.spec.ts

@@ -1,15 +1,31 @@
 import { findAssetFile, getColor, isBuild, readManifest } from '../../testUtils'
 
-test('should load both stylesheets', async () => {
+test('should load all stylesheets', async () => {
   expect(await getColor('h1')).toBe('red')
   expect(await getColor('h2')).toBe('blue')
+  expect(await getColor('.dynamic')).toBe('green')
+})
+
+test('should load dynamic import with inline', async () => {
+  const css = await page.textContent('.dynamic-inline')
+  expect(css).toMatch('.inline')
+
+  expect(await getColor('.inline')).not.toBe('yellow')
+})
+
+test('should load dynamic import with module', async () => {
+  const css = await page.textContent('.dynamic-module')
+  expect(css).toMatch('_mod_')
+
+  expect(await getColor('.mod')).toBe('yellow')
 })
 
 if (isBuild) {
   test('should remove empty chunk', async () => {
     expect(findAssetFile(/style.*\.js$/)).toBe('')
     expect(findAssetFile('main.*.js$')).toMatch(`/* empty css`)
     expect(findAssetFile('other.*.js$')).toMatch(`/* empty css`)
+    expect(findAssetFile(/async.*\.js$/)).toBe('')
   })
 
   test('should generate correct manifest', async () => {

packages/playground/css-codesplit/async.css

@@ -0,0 +1,3 @@
+.dynamic {
+  color: green;
+}

packages/playground/css-codesplit/index.html

@@ -1,2 +1,11 @@
+<h1>This should be red</h1>
+<h2>This should be blue</h2>
+
+<p class="dynamic">This should be green</p>
+<p class="inline">This should not be yellow</p>
+<p class="dynamic-inline"></p>
+<p class="mod">This should be yellow</p>
+<p class="dynamic-module"></p>
+
 <script type="module" src="/main.js"></script>
 <div id="app"></div>

packages/playground/css-codesplit/inline.css

@@ -0,0 +1,3 @@
+.inline {
+  color: yellow;
+}

packages/playground/css-codesplit/main.js

@@ -1,6 +1,15 @@
 import './style.css'
 import './main.css'
 
-document.getElementById(
-  'app'
-).innerHTML = `<h1>This should be red</h1><h2>This should be blue</h2>`
+import('./async.css')
+
+import('./inline.css?inline').then((css) => {
+  document.querySelector('.dynamic-inline').textContent = css.default
+})
+
+import('./mod.module.css').then((css) => {
+  document.querySelector('.dynamic-module').textContent = JSON.stringify(
+    css.default
+  )
+  document.querySelector('.mod').classList.add(css.default.mod)
+})

packages/playground/css-codesplit/mod.module.css

@@ -0,0 +1,3 @@
+.mod {
+  color: yellow;
+}

packages/playground/css/__tests__/css.spec.ts

@@ -342,6 +342,12 @@ test('PostCSS dir-dependency', async () => {
   }
 })
 
+// skip because #8471 is reverted
+test.skip('import dependency includes css import', async () => {
+  expect(await getColor('.css-js-dep')).toBe('green')
+  expect(await getColor('.css-js-dep-module')).toBe('green')
+})
+
 test('URL separation', async () => {
   const urlSeparated = await page.$('.url-separated')
   const baseUrl = 'url(images/dog.webp)'
@@ -417,5 +423,16 @@ test("relative path rewritten in Less's data-uri", async () => {
 test('PostCSS source.input.from includes query', async () => {
   const code = await page.textContent('.postcss-source-input')
   // should resolve assets
-  expect(code).toContain('/postcss-source-input.css?query=foo')
+  expect(code).toContain(
+    isBuild
+      ? '/postcss-source-input.css?used&query=foo'
+      : '/postcss-source-input.css?query=foo'
+  )
+})
+
+// skip because #8471 is reverted
+test.skip('aliased css has content', async () => {
+  expect(await getColor('.aliased')).toBe('blue')
+  expect(await page.textContent('.aliased-content')).toMatch('.aliased')
+  expect(await getColor('.aliased-module')).toBe('blue')
 })

packages/playground/css/aliased/bar.module.css

@@ -0,0 +1,3 @@
+.aliasedModule {
+  color: blue;
+}

packages/playground/css/aliased/foo.css

@@ -0,0 +1,3 @@
+.aliased {
+  color: blue;
+}

packages/playground/css/css-js-dep/bar.module.css

@@ -0,0 +1,3 @@
+.cssJsDepModule {
+  color: green;
+}

packages/playground/css/css-js-dep/foo.css

@@ -0,0 +1,3 @@
+.css-js-dep {
+  color: green;
+}

packages/playground/css/css-js-dep/index.js

@@ -0,0 +1,4 @@
+import './foo.css'
+import barModuleClasses from './bar.module.css'
+
+export { barModuleClasses }

packages/playground/css/css-js-dep/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "css-js-dep",
+  "private": true,
+  "type": "module",
+  "version": "1.0.0",
+  "main": "index.js"
+}

packages/playground/css/index.html

@@ -114,6 +114,13 @@ <h1>CSS</h1>
     PostCSS dir-dependency (file 2): this should be grey too
   </p>
 
+  <p class="css-js-dep">
+    import dependency includes 'import "./foo.css"': this should be green
+  </p>
+  <p class="css-js-dep-module">
+    import dependency includes 'import "./bar.module.css"': this should be green
+  </p>
+
   <p class="url-separated">
     URL separation preservation: should have valid background-image
   </p>
@@ -138,6 +145,11 @@ <h1>CSS</h1>
 
   <p>PostCSS source.input.from. Should include query</p>
   <pre class="postcss-source-input"></pre>
+
+  <p>Aliased</p>
+  <p class="aliased">import '#alias': this should be blue</p>
+  <pre class="aliased-content"></pre>
+  <p class="aliased-module">import '#alias-module': this should be blue</p>
 </div>
 
 <script type="module" src="./main.js"></script>

packages/playground/css/main.js

@@ -47,6 +47,11 @@ text('.charset-css', charset)
 import './dep.css'
 import './glob-dep.css'
 
+import { barModuleClasses } from 'css-js-dep'
+document
+  .querySelector('.css-js-dep-module')
+  .classList.add(barModuleClasses.cssJsDepModule)
+
 function text(el, text) {
   document.querySelector(el).textContent = text
 }
@@ -90,3 +95,10 @@ text('.imported-css-globEager', JSON.stringify(globEager, null, 2))
 
 import postcssSourceInput from './postcss-source-input.css?query=foo'
 text('.postcss-source-input', postcssSourceInput)
+
+import aliasContent from '#alias'
+text('.aliased-content', aliasContent)
+import aliasModule from '#alias-module'
+document
+  .querySelector('.aliased-module')
+  .classList.add(aliasModule.aliasedModule)

packages/playground/css/package.json

@@ -6,7 +6,11 @@
     "dev": "vite",
     "build": "vite build",
     "debug": "node --inspect-brk ../../vite/bin/vite",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "postinstall": "ts-node ../../../scripts/patchFileDeps.ts"
+  },
+  "dependencies": {
+    "css-js-dep": "file:./css-js-dep"
   },
   "devDependencies": {
     "css-dep": "link:./css-dep",

packages/playground/css/vite.config.js

@@ -10,7 +10,9 @@ module.exports = {
   resolve: {
     alias: {
       '@': __dirname,
-      spacefolder: __dirname + '/folder with space'
+      spacefolder: __dirname + '/folder with space',
+      '#alias': __dirname + '/aliased/foo.css',
+      '#alias-module': __dirname + '/aliased/bar.module.css'
     }
   },
   css: {

packages/vite/src/node/importGlob.ts

@@ -9,6 +9,7 @@ import {
   preloadMarker,
   preloadMethod
 } from './plugins/importAnalysisBuild'
+import { isCSSRequest } from './plugins/css'
 import {
   blankReplacer,
   cleanUrl,
@@ -149,14 +150,16 @@ export async function transformImportGlob(
         await fsp.readFile(path.join(base, files[i]), 'utf-8')
       )},`
     } else {
+      const importeeUrl = isCSSRequest(importee) ? `${importee}?used` : importee
       if (isEager) {
         const identifier = `__glob_${importIndex}_${i}`
+        // css imports injecting a ?used query to export the css string
         importsString += `import ${
           isEagerDefault ? `` : `* as `
-        }${identifier} from ${JSON.stringify(importee)};`
+        }${identifier} from ${JSON.stringify(importeeUrl)};`
         entries += ` ${JSON.stringify(file)}: ${identifier},`
       } else {
-        let imp = `import(${JSON.stringify(importee)})`
+        let imp = `import(${JSON.stringify(importeeUrl)})`
         if (!normalizeUrl && preload) {
           imp =
             `(${isModernFlag}` +

packages/vite/src/node/plugins/css.ts

@@ -102,6 +102,7 @@ const htmlProxyRE = /(\?|&)html-proxy\b/
 const commonjsProxyRE = /\?commonjs-proxy/
 const inlineRE = /(\?|&)inline\b/
 const inlineCSSRE = /(\?|&)inline-css\b/
+const usedRE = /(\?|&)used\b/
 const varRE = /^var\(/i
 
 const enum PreprocessLang {
@@ -369,19 +370,18 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
       }
 
       let code: string
-      if (modulesCode) {
-        code = modulesCode
-      } else {
-        let content = css
-        if (config.build.minify) {
-          content = await minifyCSS(content, config)
+      if (usedRE.test(id)) {
+        if (modulesCode) {
+          code = modulesCode
+        } else {
+          let content = css
+          if (config.build.minify) {
+            content = await minifyCSS(content, config)
+          }
+          code = `export default ${JSON.stringify(content)}`
         }
-        // marking as pure to make it tree-shakable by minifier
-        // but the module itself is still treated as a non tree-shakable module
-        // because moduleSideEffects is 'no-treeshake'
-        code = `export default /* #__PURE__ */ (() => ${JSON.stringify(
-          content
-        )})()`
+      } else {
+        code = `export default ''`
       }
 
       return {

packages/vite/src/node/plugins/importAnalysisBuild.ts

@@ -5,11 +5,11 @@ import { init, parse as parseImports } from 'es-module-lexer'
 import type { OutputChunk, SourceMap } from 'rollup'
 import type { RawSourceMap } from '@ampproject/remapping'
 import { transformImportGlob } from '../importGlob'
-import { combineSourcemaps } from '../utils'
+import { bareImportRE, combineSourcemaps } from '../utils'
 import type { Plugin } from '../plugin'
 import type { ResolvedConfig } from '../config'
 import { genSourceMapUrl } from '../server/sourcemap'
-import { removedPureCssFilesCache } from './css'
+import { isCSSRequest, removedPureCssFilesCache } from './css'
 
 /**
  * A flag for injected helpers. This flag will be set to `false` if the output
@@ -148,9 +148,12 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
           e: end,
           ss: expStart,
           se: expEnd,
+          n: specifier,
           d: dynamicIndex
         } = imports[index]
 
+        const isDynamic = dynamicIndex > -1
+
         // import.meta.glob
         if (
           source.slice(start, end) === 'import.meta' &&
@@ -188,11 +191,32 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin {
           continue
         }
 
-        if (dynamicIndex > -1 && insertPreload) {
+        if (isDynamic && insertPreload) {
           needPreloadHelper = true
-          const original = source.slice(expStart, expEnd)
-          const replacement = `${preloadMethod}(() => ${original},${isModernFlag}?"${preloadMarker}":void 0)`
-          str().overwrite(expStart, expEnd, replacement, { contentOnly: true })
+          str().prependLeft(expStart, `${preloadMethod}(() => `)
+          str().appendRight(
+            expEnd,
+            `,${isModernFlag}?"${preloadMarker}":void 0)`
+          )
+        }
+
+        // Differentiate CSS imports that use the default export from those that
+        // do not by injecting a ?used query - this allows us to avoid including
+        // the CSS string when unnecessary (esbuild has trouble tree-shaking
+        // them)
+        if (
+          specifier &&
+          isCSSRequest(specifier) &&
+          // always inject ?used query when it is a dynamic import
+          // because there is no way to check whether the default export is used
+          (source.slice(expStart, start).includes('from') || isDynamic) &&
+          // edge case for package names ending with .css (e.g normalize.css)
+          !(bareImportRE.test(specifier) && !specifier.includes('/'))
+        ) {
+          const url = specifier.replace(/\?|$/, (m) => `?used${m ? '&' : ''}`)
+          str().overwrite(start, end, isDynamic ? `'${url}'` : url, {
+            contentOnly: true
+          })
         }
       }