fix: normalize same-origin absolute URLs for client-side navigation by Divkix · Pull Request #336 · cloudflare/vinext

Divkix · 2026-03-08T00:25:09Z

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

When <Link href="https://example.com/path"> is used and example.com matches the current origin, vinext now does SPA navigation instead of a full page reload. This matches Next.js behavior. Adds toSameOriginPath() utility that extracts the local path from a same-origin absolute URL. Applied consistently across: - link.tsx handleClick() and prefetch paths - navigation.ts navigateImpl() (App Router) - router.ts push()/replace() (Pages Router hook + singleton) Closes cloudflare#335

pkg-pr-new · 2026-03-08T00:25:48Z

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

commit: 87bccd7

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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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packages/vinext/src/shims/link.tsx

packages/vinext/src/shims/url-utils.ts

Use window.location.origin as base for `//` URLs so they resolve correctly for same-origin detection, while keeping `new URL(url)` (no base) for http/https URLs to preserve existing behavior. Addresses Copilot review comment on PR cloudflare#336.

james-elicx · 2026-03-08T08:46:39Z

/bigbonk review

ask-bonk

Clean, well-scoped fix. The toSameOriginPath() utility is correct and the integration across all navigation paths (Link, App Router, Pages Router hook + singleton) is thorough and consistent.

All tests pass (36 link tests, 568 shim tests), typecheck and lint are clean.

Two minor observations below — neither blocks merge.

ask-bonk · 2026-03-08T08:48:13Z

packages/vinext/src/shims/link.tsx

    if (!observer) return;

-    observerCallbacks.set(node, () => prefetchUrl(localizedHref));
+    observerCallbacks.set(node, () => prefetchUrl(hrefToPrefetch));


Minor: prefetchUrl() already normalizes same-origin URLs internally (lines 150-156). When the IntersectionObserver fires this callback, toSameOriginPath will be called a second time inside prefetchUrl. This is harmless (cheap, idempotent, correct) but the double normalization could be avoided by passing hrefToPrefetch here, which you already do — so it only re-normalizes if the href was already local. Just noting the interaction; no change needed.

ask-bonk · 2026-03-08T08:48:13Z

packages/vinext/src/shims/link.tsx

+    // External links: let the browser handle it.
+    // Same-origin absolute URLs (e.g. http://localhost:3000/about) are
+    // normalized to local paths so they get client-side navigation.
+    let navigateHref = resolvedHref;


Nice detail: using resolvedHref (which incorporates the as prop) for the external check, and then feeding the normalized path into resolveRelativeHref / withBasePath downstream. The as-prop case is handled correctly because as would typically be a local path, but if someone passes an absolute URL as as, this now does the right thing.

tests/link.test.ts

ask-bonk · 2026-03-08T08:48:26Z

Review submitted. Here's a summary of my findings:

Approved. This is a clean, well-scoped fix for #335.

What the PR does: Adds a toSameOriginPath() utility that uses new URL() + origin comparison to detect same-origin absolute URLs and extract their local path. This is applied consistently in all 4 navigation code paths: Link.handleClick(), Link prefetch (both IntersectionObserver setup and prefetchUrl()), App Router navigateImpl(), and Pages Router push/replace (both useRouter hook and Router singleton).

What I verified:

All 36 link tests and 568 shim tests pass
Typecheck clean, lint clean
The toSameOriginPath() implementation correctly handles: same-origin http/https, protocol-relative URLs (using window.location.origin as base for // URLs only), cross-origin, different ports, different schemes, server-side (returns null), and invalid URLs
SSR rendering correctly preserves the absolute URL in the href attribute (normalization only happens at click/navigate time, not render time)

One minor suggestion: The test comment on line 247 of tests/link.test.ts references anthropics/vinext instead of cloudflare/vinext — submitted as an inline suggestion.

github run

Co-authored-by: ask-bonk[bot] <249159057+ask-bonk[bot]@users.noreply.github.com>

james-elicx · 2026-03-08T08:51:36Z

Nice one!

Copilot AI review requested due to automatic review settings March 8, 2026 00:25

Divkix mentioned this pull request Mar 8, 2026

Unexpected next/link Behavior: <Link> with same-origin absolute URL triggers full page reload #335

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Copilot started reviewing on behalf of Divkix March 8, 2026 00:25 View session

Copilot AI reviewed Mar 8, 2026

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ask-bonk bot approved these changes Mar 8, 2026

View reviewed changes

Update tests/link.test.ts

9c2a132

Co-authored-by: ask-bonk[bot] <249159057+ask-bonk[bot]@users.noreply.github.com>

james-elicx enabled auto-merge (squash) March 8, 2026 08:51

james-elicx merged commit 6762472 into cloudflare:main Mar 8, 2026
15 checks passed

Divkix deleted the fix/link-same-origin-absolute-url branch March 8, 2026 14:09

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fix: normalize same-origin absolute URLs for client-side navigation#336

fix: normalize same-origin absolute URLs for client-side navigation#336
james-elicx merged 3 commits intocloudflare:mainfrom
Divkix:fix/link-same-origin-absolute-url

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Divkix commented Mar 8, 2026

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