Revert "fix: allow css to be written for systemjs output (vitejs#5902)"

This reverts commit 780b4f5.

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

@@ -492,11 +492,7 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
           // this is a shared CSS-only chunk that is empty.
           pureCssChunks.add(chunk.fileName)
         }
-        if (
-          opts.format === 'es' ||
-          opts.format === 'cjs' ||
-          opts.format === 'system'
-        ) {
+        if (opts.format === 'es' || opts.format === 'cjs') {
           const cssAssetName = chunk.name + '.css'
 
           chunkCSS = resolveAssetUrlsInCss(chunkCSS, cssAssetName)
@@ -558,7 +554,7 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
           .join('|')
           .replace(/\./g, '\\.')
         const emptyChunkRE = new RegExp(
-          opts.format === 'es' || opts.format === 'system'
+          opts.format === 'es'
             ? `\\bimport\\s*["'][^"']*(?:${emptyChunkFiles})["'];\n?`
             : `\\brequire\\(\\s*["'][^"']*(?:${emptyChunkFiles})["']\\);\n?`,
           'g'

playground/legacy/__tests__/legacy.spec.ts

@@ -57,17 +57,6 @@ test('correctly emits styles', async () => {
   expect(await getColor('#app')).toBe('red')
 })
 
-// dynamic import css
-test('should load dynamic import with css', async () => {
-  await page.click('#dynamic-css-button')
-  await untilUpdated(
-    () =>
-      page.$eval('#dynamic-css', (node) => window.getComputedStyle(node).color),
-    'rgb(255, 0, 0)',
-    true
-  )
-})
-
 describe.runIf(isBuild)('build', () => {
   test('should generate correct manifest', async () => {
     const manifest = readManifest()

playground/legacy/index.html

@@ -4,6 +4,4 @@ <h1 id="app"></h1>
 <div id="features-after-corejs-3"></div>
 <div id="babel-helpers"></div>
 <div id="assets"></div>
-<button id="dynamic-css-button">dynamic css</button>
-<div id="dynamic-css"></div>
 <script type="module" src="./main.js"></script>

playground/legacy/main.js

@@ -43,14 +43,6 @@ import('./immutable-chunk.js')
     text('#assets', assets.join('\n'))
   })
 
-// dynamic css
-document
-  .querySelector('#dynamic-css-button')
-  .addEventListener('click', async () => {
-    await import('./dynamic.css')
-    text('#dynamic-css', 'dynamic import css')
-  })
-
 function text(el, text) {
   document.querySelector(el).textContent = text
 }

playground/legacy/package.json

@@ -6,7 +6,6 @@
     "dev": "vite",
     "build": "vite build --debug legacy",
     "build:custom-filename": "vite --config ./vite.config-custom-filename.js build  --debug legacy",
-    "build:dynamic-css": "vite --config ./vite.config-dynamic-css.js build  --debug legacy",
     "build:multiple-output": "vite --config ./vite.config-multiple-output.js build",
     "debug": "node --inspect-brk ../../packages/vite/bin/vite",
     "preview": "vite preview"