[b84330808]

What kind of change does this PR introduce?

Bug fix, follow-up to #1802 (not released yet).

When a bundler folds the Node build into a CommonJS file, import.meta.url is undefined and lib/document.node.js falls back to createRequire('file:///'). That URL has no drive letter, so on Windows createRequire throws while the bundle is loading:

TypeError [ERR_INVALID_ARG_VALUE]: The argument 'filename' must be a file URL object, file URL string, or absolute path string. Received 'file:///'

Repro on Windows with master packed via npm pack:

// index.mjs
import PDFDocument from 'pdfkit';
console.log(typeof PDFDocument);

npx esbuild index.mjs --bundle --platform=node --format=cjs --outfile=dist/index.cjs
node dist/index.cjs

The fallback is now /, which is absolute on every platform. On Linux and macOS it resolves the same way file:/// did. On Windows the bundle now loads, an unregistered standard font still fails with the "Cannot load the standard font" error, and fonts passed to registerStdFonts() render.

The "as CommonJS" cases in tests/unit/bundling.spec.js already cover this. They fail on Windows without this change and pass with it; CI only runs on Ubuntu, so it didn't show up there.

Checklist:

• Unit Tests N/A (covered by the existing bundling.spec.js CommonJS cases)
• Documentation N/A
• Update CHANGELOG.md N/A (the bug is in unreleased code from Let the Node build be bundled: export registerStdFonts, resolve standard fonts and the ICC profile on first use #1802)
• Ready to be merged

I used Claude Code to write this change.

[Copilot]

🟢 Approval recommended

The narrowly scoped fix preserves normal module resolution, and existing CommonJS bundling tests cover the affected loading and font-registration behavior.

No open issues 🎉

What changed in this PR

Fixes Windows load failures when PDFKit’s Node build is bundled as CommonJS, following up on #1802.

Changes:

• Replaces the createRequire fallback URL file:/// with /, avoiding Windows drive-letter validation failures while preserving normal module loading.
• Updates the comment to explain the platform-specific reason for the fallback.

File	Description
lib/​document.node.js	Uses a cross-platform fallback for createRequire and documents why it is needed.

_{Review effort: Balanced}