fix: srcset handling in html

packages/vite/src/node/server/middlewares/indexHtml.ts

@@ -27,7 +27,8 @@ import {
   ensureWatchedFile,
   fsPathFromId,
   injectQuery,
-  normalizePath
+  normalizePath,
+  processSrcSetSync
 } from '../../utils'
 import type { ModuleGraph } from '../moduleGraph'
 
@@ -92,18 +93,23 @@ const processNodeUrl = (
     originalUrl !== '/' &&
     htmlPath === '/index.html'
   ) {
-    // #3230 if some request url (localhost:5173/a/b) return to fallback html, the relative assets
+    const replacer = (url: string) =>
+      path.posix.join(
+        config.base,
+        path.posix.relative(originalUrl, config.base),
+        url.slice(1)
+      )
+
+    // #3230 if some request url (localhost:3000/a/b) return to fallback html, the relative assets
     // path will add `/a/` prefix, it will caused 404.
     // rewrite before `./index.js` -> `localhost:5173/a/index.js`.
     // rewrite after `../index.js` -> `localhost:5173/index.js`.
     s.overwrite(
       node.value!.loc.start.offset,
       node.value!.loc.end.offset,
-      `"${path.posix.join(
-        path.posix.relative(originalUrl, '/'),
-        url.slice(1)
-      )}"`,
-      { contentOnly: true }
+      node.name === 'srcset'
+        ? `"${processSrcSetSync(url, ({ url }) => replacer(url))}"`
+        : `"${replacer(url)}"`
     )
   }
 }

packages/vite/src/node/utils.ts

@@ -557,11 +557,16 @@ interface ImageCandidate {
 }
 const escapedSpaceCharacters = /( |\\t|\\n|\\f|\\r)+/g
 const imageSetUrlRE = /^(?:[\w\-]+\(.*?\)|'.*?'|".*?"|\S*)/
-export async function processSrcSet(
-  srcs: string,
-  replacer: (arg: ImageCandidate) => Promise<string>
-): Promise<string> {
-  const imageCandidates: ImageCandidate[] = splitSrcSet(srcs)
+function reduceSrcset(ret: { url: string; descriptor: string }[]) {
+  return ret.reduce((prev, { url, descriptor }, index) => {
+    descriptor ??= ''
+    return (prev +=
+      url + ` ${descriptor}${index === ret.length - 1 ? '' : ', '}`)
+  }, '')
+}
+
+function splitSrcSetDescriptor(srcs: string): ImageCandidate[] {
+  return splitSrcSet(srcs)
     .map((s) => {
       const src = s.replace(escapedSpaceCharacters, ' ').trim()
       const [url] = imageSetUrlRE.exec(src) || []
@@ -572,21 +577,30 @@ export async function processSrcSet(
       }
     })
     .filter(({ url }) => !!url)
+}
 
-  const ret = await Promise.all(
-    imageCandidates.map(async ({ url, descriptor }) => {
-      return {
-        url: await replacer({ url, descriptor }),
-        descriptor
-      }
-    })
-  )
+export function processSrcSet(
+  srcs: string,
+  replacer: (arg: ImageCandidate) => Promise<string>
+): Promise<string> {
+  return Promise.all(
+    splitSrcSetDescriptor(srcs).map(async ({ url, descriptor }) => ({
+      url: await replacer({ url, descriptor }),
+      descriptor
+    }))
+  ).then((ret) => reduceSrcset(ret))
+}
 
-  return ret.reduce((prev, { url, descriptor }, index) => {
-    descriptor ??= ''
-    return (prev +=
-      url + ` ${descriptor}${index === ret.length - 1 ? '' : ', '}`)
-  }, '')
+export function processSrcSetSync(
+  srcs: string,
+  replacer: (arg: ImageCandidate) => string
+): string {
+  return reduceSrcset(
+    splitSrcSetDescriptor(srcs).map(({ url, descriptor }) => ({
+      url: replacer({ url, descriptor }),
+      descriptor
+    }))
+  )
 }
 
 function splitSrcSet(srcs: string) {

playground/assets/__tests__/assets.spec.ts

@@ -192,7 +192,7 @@ describe('image', () => {
       expect(s).toMatch(
         isBuild
           ? /\/foo\/assets\/asset\.\w{8}\.png \d{1}x/
-          : /\.\/nested\/asset\.png \d{1}x/
+          : /\/foo\/nested\/asset\.png \d{1}x/
       )
     })
   })

playground/env/__tests__/env.spec.ts

@@ -3,7 +3,7 @@ import { isBuild, page } from '~utils'
 const mode = isBuild ? `production` : `development`
 
 test('base', async () => {
-  expect(await page.textContent('.base')).toBe('/')
+  expect(await page.textContent('.base')).toBe('/env/')
 })
 
 test('mode', async () => {
@@ -46,9 +46,15 @@ test('env object', async () => {
     VITE_EFFECTIVE_MODE_FILE_NAME: `.env.${mode}`,
     CUSTOM_PREFIX_ENV_VARIABLE: '1',
     VITE_CUSTOM_ENV_VARIABLE: '1',
-    BASE_URL: '/',
+    BASE_URL: '/env/',
     MODE: mode,
     DEV: !isBuild,
     PROD: isBuild
   })
 })
+
+if (!isBuild) {
+  test('relative url import script return import.meta.url', async () => {
+    expect(await page.textContent('.url')).toMatch('/env/index.js')
+  })
+}

playground/env/index.html

@@ -14,6 +14,7 @@ <h1>Environment Variables</h1>
 <p>import.meta.env.VITE_INLINE: <code class="inline"></code></p>
 <p>process.env.NODE_ENV: <code class="node-env"></code></p>
 <p>import.meta.env: <span class="pre env-object"></span></p>
+<p>import.meta.url: <span class="pre url"></span></p>
 
 <script type="module">
   text('.base', import.meta.env.BASE_URL)
@@ -31,6 +32,7 @@ <h1>Environment Variables</h1>
     document.querySelector(el).textContent = text
   }
 </script>
+<script type="module" src="./index.js"></script>
 
 <style>
   .pre {

playground/env/index.js

@@ -0,0 +1,5 @@
+text('.url', import.meta.url)
+
+function text(el, text) {
+  document.querySelector(el).textContent = text
+}

playground/env/vite.config.js

@@ -1,5 +1,9 @@
 const { defineConfig } = require('vite')
 
 module.exports = defineConfig({
-  envPrefix: ['VITE_', 'CUSTOM_PREFIX_']
+  base: '/env/',
+  envPrefix: ['VITE_', 'CUSTOM_PREFIX_'],
+  build: {
+    outDir: 'dist/env'
+  }
 })