fix(adapters): sync raw node req.url with event.url in fromNodeHandler

[pi0x]

Context

Follow-up to #1432 (percent-decode normalization no longer mutates the shared _url, fixed in a1cf066).

Legacy Node handlers invoked via fromNodeHandler route on the raw req.url. Until now, h3-level URL rewrites (withBase, mount) only reached that raw request through srvx's implicit NodeRequestURL pathname write-back (srvx#118) — mutation-at-a-distance through the shared parsed URL object.

That channel is now half-dead: since a1cf066, requests whose pathname needs percent-decode normalization get a detached event.url clone, so withBase mutations never reach the shared NodeRequestURL, and legacy handlers saw the original un-stripped URL for such requests (e.g. withBase("/api", fromNodeHandler(m)) handed m a req.url of /api/h%65llo instead of /hello).

Change

Make the propagation explicit at the adapter boundary instead of relying on the shared-object side effect:

• fromNodeHandler computes h3's view (event.url.pathname + event.url.search); if it differs from the raw req.url, it swaps it in before calling the legacy handler and restores the original once the handler settles.
• When the views already match (no rewrite, no decode — the common case), the raw request is never touched.

Behavior for legacy middleware is unchanged vs. the pre-#1432 node behavior (they already received the decoded pathname, since the constructor write-back fired before any handler ran) — except it now also works for percent-encoded paths, which the implicit channel never covered after the clone fix.

This also unblocks srvx dropping the implicit write-back from srvx#118: h3 no longer depends on it, so the raw IncomingMessage.url can stay pristine wire data for every other consumer.

Tests

New node-target regression test: withBase("/api", fromNodeHandler(...)) echoing req.url:

• /api/hello?q=1 → legacy handler sees /hello?q=1
• /api/h%65llo → legacy handler sees /hello (failed before this change)
• raw req.url is restored to /api/h%65llo after the handler settles (asserted via onResponse)

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Improved compatibility for legacy Node.js handlers so they now see the same normalized URL as the app route.
  • Preserved the original request URL after handling, reducing the risk of affecting later routing or response behavior.
  • Added coverage for base-path stripping, URL rewrites, and percent-decoding behavior to help prevent regressions.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 1e5302f5-bf4b-4a69-8357-e14c35d106e0

📥 Commits

Reviewing files that changed from the base of the PR and between a1cf066 and 2ed63a5.

📒 Files selected for processing (2)

• src/adapters.ts
• test/app.test.ts

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📝 Walkthrough

Walkthrough

The fromNodeHandler runtime path in src/adapters.ts now normalizes node.req.url to match the h3 event's URL before invoking the legacy Node handler, temporarily overwriting it and restoring the original value afterward. A new test verifies this base-stripping and normalization behavior, including URL restoration.

Changes

fromNodeHandler URL Sync

Layer / File(s)	Summary
Normalize and restore req.url src/adapters.ts	Computes URL from event.url.pathname + event.url.search, temporarily overwrites node.req.url if it differs, invokes callNodeHandler(), and restores original value via .finally().
Test coverage for URL sync test/app.test.ts	Adds withBase import and a Node-only test that registers /api/** with withBase(fromNodeHandler(...)), verifying base-stripped/decoded URL visibility and restoration of raw req.url.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related issues

• Percent-decode normalization side-effects the original request URL on Node (runtime divergence) #1432: Addresses Node URL normalization vs raw req.url behavior, matching this PR's fix for preserving the original request URL while exposing the h3-normalized view.

Suggested reviewers: pi0

Poem

A rabbit hops through URLs anew,
Stripping bases, restoring true,
node.req.url borrowed for a spell,
Then given back—all is well!
🐇✨ /api/hop → /hop, and back again!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: syncing Node req.url with event.url in fromNodeHandler.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/from-node-handler-url-sync

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