Importing resource with URL no longer bundles the asset (>=7.1.0 regression)

[nocive]

Describe the bug

A standard integration of react-pdf with pdfjs-dist as described in their documentation works correctly with vite 7.0.6 and older but not with 7.1.0 or newer.

Given the following minimal example of react-pdf:

import { pdfjs } from 'react-pdf'

pdfjs.GlobalWorkerOptions.workerSrc = new URL(
  'pdfjs-dist/build/pdf.worker.min.mjs',
  import.meta.url,
).toString()

With vite 7.0.6 or older the pdf.worker.min.mjs asset is correctly bundled and present in the dist directory:

dist/assets/pdf.worker.min--PgD6g2g.mjs              1,035.02 kB

However, with vite 7.1.0 or newer it is not.

Reproduction

https://stackblitz.com/edit/vitejs-vite-ybwgh9rm?file=src%2Fmain.js

Steps to reproduce

• Open the reproduction
• Build it with yarn build and observe the pdf.worker.min.mjs file being bundled by vite
• Upgrade vite to 7.1.0 or newer with yarn add vite@7.1.0
• Run yarn build again and observe the absence of the pdf.worker.min.mjs asset.

System Info

System:
    OS: Linux 6.12 Manjaro Linux
    CPU: (12) x64 13th Gen Intel(R) Core(TM) i7-1365U
    Memory: 21.57 GB / 31.01 GB
    Container: Yes
    Shell: 5.3.0 - /bin/bash
  Binaries:
    Node: 24.4.1 - /usr/bin/node
    Yarn: 4.9.1 - /usr/bin/yarn
    npm: 11.4.2 - /usr/bin/npm
  npmPackages:
    @vitejs/plugin-react: ^5.0.0 => 5.0.0 
    vite: 7.0.6 => 7.0.6

Used Package Manager

yarn

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

It seems this is caused by #20358.

A workaround is to remove the line breaks in new URL(..., import.meta.url):

pdfjs.GlobalWorkerOptions.workerSrc = new URL('pdfjs-dist/build/pdf.worker.min.mjs', import.meta.url)

[nocive]

Can confirm the issue is fixed.
Thank you for the prompt reaction & fix 👍