🚨 [REGRESSION][6.0.11 -> 6.1.0] Building with Web Worker fails

[repulsio]

Describe the bug

This used to build successfully in version 6.0.11. Started failing in 6.1.0.

Code:

const worker = new Worker(new URL('./worker', import.meta.url));

Build:

vite build

✓ 30 modules transformed.
x Build failed in 136ms
error during build:
[vite:worker-import-meta-url] Expected ',', got ':'
file: /home/nonroot/app/browser/src/worker/singleton.ts
    at getRollupError (file:///home/nonroot/app/browser/node_modules/rollup/dist/es/shared/parseAst.js:397:41)
    at convertProgram (file:///home/nonroot/app/browser/node_modules/rollup/dist/es/shared/parseAst.js:1085:26)
    at parseAstAsync (file:///home/nonroot/app/browser/node_modules/rollup/dist/es/shared/parseAst.js:2071:106)
    at async parseWorkerOptions (file:///home/nonroot/app/browser/node_modules/vite/dist/node/chunks/dep-CfG9u7Cn.js:46636:23)
    at async getWorkerType (file:///home/nonroot/app/browser/node_modules/vite/dist/node/chunks/dep-CfG9u7Cn.js:46675:22)
    at async Object.transform (file:///home/nonroot/app/browser/node_modules/vite/dist/node/chunks/dep-CfG9u7Cn.js:46721:30)
    at async transform (file:///home/nonroot/app/browser/node_modules/rollup/dist/es/shared/node-entry.js:20689:16)
    at async ModuleLoader.addModuleSource (file:///home/nonroot/app/browser/node_modules/rollup/dist/es/shared/node-entry.js:20902:36)

Reproduction

Please see code below

Steps to reproduce

Code:

const worker = new Worker(new URL('./worker', import.meta.url));

Build:

vite build

System Info

System:
    OS: Linux 6.10 Debian GNU/Linux 11 (bullseye) 11 (bullseye)
    CPU: (10) arm64 unknown
    Memory: 6.23 GB / 7.65 GB
    Container: Yes
    Shell: 5.1.4 - /bin/bash
  Binaries:
    Node: 20.13.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.8.1 - /usr/local/bin/npm
  npmPackages:
    vite: ^6.1.0 => 6.1.0

Used Package Manager

npm

Logs

No response

Validations

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• 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.
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• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

I couldn't reproduce https://stackblitz.com/edit/vitejs-vite-lrkn1iir?file=src%2Fmain.js Please provide a full code which can reproduce your issue.

[github-actions]

Hello @repulsio. Please provide a minimal reproduction using a GitHub repository or StackBlitz. Issues marked with needs reproduction will be closed if they have no activity within 3 days.

[repulsio]

@hi-ogawa, thank you for starting the stackblitz. I've added some changes to reproduce the issue:

https://stackblitz.com/edit/vitejs-vite-jno6nvaz?file=src%2Fmain.js

Turns out that wrapping it inside of an IIFE and running postMessage() causes the issue for some reason

Also it's really strange how commenting out postMessage() (but keeping the IIFE) causes the build to succeed

[hi-ogawa]

It's likely a regression of #19010. This simple case should bail out early here, but some odd string });\n} ended up passed to parseAstAsync instead.

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

Lines 144 to 149 in 00deea4

	const endIndex = findClosingParen(clean, i)
	// case: ') ... ,' mean no worker options params
	if (commaIndex > endIndex) {
	return 'classic'
	}