fix(worker): resolve WebKit compat with inline workers by deferring blob URL revocation

[Copilot]

Problem

Inline workers generated by Vite were incompatible with Playwright's WebKit (and potentially other WebKit-based browsers) due to premature Blob URL revocation. The issue occurred because Vite's WorkerWrapper code immediately revoked the Blob URL in a finally block, invalidating it before WebKit could properly initialize the worker.

// Problematic code - URL revoked immediately
export default function WorkerWrapper(options) {
  let objURL;
  try {
    objURL = blob && (self.URL || self.webkitURL).createObjectURL(blob);
    const worker = new Worker(objURL, options);
    return worker;
  } catch(e) {
    // fallback...
  } finally {
    objURL && (self.URL || self.webkitURL).revokeObjectURL(objURL); // ❌ Too early!
  }
}

This caused worker initialization failures in WebKit environments, particularly affecting testing with Playwright.

Solution

Following @sapphi-red's suggestion in #19238, this fix moves the URL revocation logic inside the worker script for classic workers (similar to how module workers already handled it), allowing the Blob URL to remain valid throughout the worker's lifecycle.

Changes made:

1. Added URL revocation to classic worker blob content: Classic workers now include (self.URL || self.webkitURL).revokeObjectURL(self.location.href); at the start of their script
2. Removed the problematic finally block: No more immediate URL revocation that was breaking WebKit
3. Maintained existing error handling: Worker error listeners still clean up URLs on failure

Before (classic workers):

new Blob(['', jsContent], { type: "text/javascript;charset=utf-8" })
// + finally block that immediately revokes URL ❌

After (classic workers):

new Blob([
  '(self.URL || self.webkitURL).revokeObjectURL(self.location.href);',
  jsContent
], { type: "text/javascript;charset=utf-8" })
// No immediate revocation ✅

Module workers were already handled correctly and remain unchanged.

Testing

• ✅ Existing worker tests continue to pass
• ✅ Generated code verified to include proper URL revocation in worker content
• ✅ Build process works correctly with the changes
• ✅ Linting passes

Related

Closes #19238
Closes #19565

Co-authored-by: sapphi-red 49056869+sapphi-red@users.noreply.github.com

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• vite.dev
  • Triggering command: /home/REDACTED/.cache/playwright-bin/chromium_headless_shell-1181/chrome-linux/headless_shell --disable-field-trial-config --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-back-forward-cache --disable-breakpad --disable-client-side-phishing-detection --disable-component-extensions-with-REDACTED-pages --disable-component-update --no-default-browser-check --disable-default-apps --disable-dev-shm-usage --disable-extensions --disable-features=AcceptCHFrame,AutoExpandDetailsElement,AvoidUnnecessaryBeforeUnloadCheckSync,CertificateTransparencyComponentUpdater,DestroyProfileOnBrowserClose,DialMediaRouteProvider,ExtensionManifestV2Disabled,GlobalMediaControls,HttpsUpgrades,ImprovedCookieControls,LazyFrameLoading,LensOverlay,MediaRouter,PaintHolding,ThirdPartyStoragePartitioning,Translate --allow-pre-commit-input --disable-hang-monitor --disable-ipc-flooding-protection --disable-popup-blocking --disable-prompt-on-repost --disable-renderer-REDACTEDing --force-color-profile=srgb --metrics-recording-only --no-first-run --password-store=basic --use-mock-keychain --no-service-autorun --export-tagged-pdf --disable-search-engine-choice-screen --unsafely-disable-devtools-self-xss-warnings --edge-skip-compat-layer-relaunch --enable-automation --headless --hide-scrollbars --mute-audio --blink-settings=primaryHoverType=2,availableHoverTypes=2,primaryPointerType=4,availablePointerTypes=4 --no-sandbox --no-sandbox --disable-setuid-sandbox --user-data-dir=/tmp/playwright_chromiumdev_profile-YUN3Kl --remote-debugging-pipe --no-startup-window (dns block)
• workers.cloudflare.com
  • Triggering command: node (vitest 3) (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

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[sapphi-red]

I confirmed that #19238 works with this change.