fix: normalize same-origin absolute URLs for client-side navigation

[Divkix]

Summary

Fixes #335

• Adds toSameOriginPath() utility that extracts the local path (pathname + search + hash) from a same-origin absolute URL, returning null for truly external URLs or server-side contexts
• Updates link.tsx handleClick() and prefetch paths to normalize same-origin URLs before the external URL bail-out
• Updates navigation.ts navigateImpl() (App Router) to normalize before external URL check
• Updates router.ts push()/replace() in both the useRouter hook and Router singleton (Pages Router)

Root Cause

isExternalUrl() treated any URL with a scheme as external — no same-origin comparison. When <Link href="http://localhost:3000/about"> was used and the origin matched, it triggered a full page reload instead of SPA navigation.

Test plan

• Unit tests for toSameOriginPath() — same-origin returns local path, cross-origin returns null, server returns null, preserves search/hash
• SSR rendering tests for <Link> with absolute URLs
• isExternalUrl() still correctly identifies truly external URLs
• pnpm test tests/link.test.ts — 35 tests pass
• pnpm test tests/shims.test.ts — 568 tests pass
• pnpm run typecheck — clean
• pnpm run lint — clean

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/vinext@336

commit: ed75031

[Copilot]

Pull request overview

This PR fixes client-side navigation for same-origin absolute URLs (e.g. http://localhost:3000/about) by normalizing them to local paths before “external URL” bail-outs, aligning behavior with Next.js and resolving #335.

Changes:

• Added toSameOriginPath() utility to convert same-origin absolute URLs to pathname + search + hash (or return null for external/server contexts).
• Updated Link, App Router navigation, and Pages Router push/replace to normalize same-origin absolute URLs before delegating to full-page navigation.
• Added unit tests for toSameOriginPath() and SSR rendering checks for <Link> with absolute URLs.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/link.test.ts	Adds tests for same-origin normalization utility and SSR output for absolute hrefs.
packages/vinext/src/shims/url-utils.ts	Introduces shared toSameOriginPath() helper used by multiple navigation shims.
packages/vinext/src/shims/link.tsx	Normalizes same-origin absolute URLs for prefetch/click handling to enable SPA navigation.
packages/vinext/src/shims/navigation.ts	Normalizes same-origin absolute URLs before external URL handling in App Router navigation.
packages/vinext/src/shims/router.ts	Normalizes same-origin absolute URLs before external URL handling in Pages Router push/replace.

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