[Brooooooklyn]

Problem

In Svelte pages, useParams() goes stale when you navigate between two URLs that use the same page component. On /posts/[slug], clicking a <Link> from /posts/a to /posts/b updates the page props, but const params = useParams(); params.slug still reads "a".

App.svelte replaced the params object on every navigation. useParams() reads the context only once, when the component is set up, so the page and its layouts kept the old object.

before:  navigate -> params = { slug: 'b' }        (new object)
         page still holds old object -> slug 'a'

after:   navigate -> clear keys, assign { slug: 'b' } (same object)
         page holds same object       -> slug 'b'

What changed

• packages/svelte/src/runtime/App.svelte: params are now updated in place, the same way shared data already was. The old replaceShared helper is now replaceInPlace(target, next) and is used for both.

Tests

• New packages/svelte/test/integration/use-params-navigation.test.ts: mounts the real App.svelte in Chromium with a page that calls useParams(), updates the stores the way the Svelte pages client does on a Link navigation, and checks that the rendered slug changes from a to b. It fails without the fix.
• The existing Svelte pages client tests (including the shared-data replacement test) still pass.

To check

• useParams() now always returns the same object for the life of the app, as useShared() already does.

🤖 Generated with Claude Code

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-27T07:56:11.238179Z	2d81b43	New commits

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[Brooooooklyn]

@codex review

[cloudflare-workers-and-pages]

🚀 Deploying Preview to Cloudflare 🚀

Preview URL: https://fix-svelte-use-params-refresh-void-cloud.voidzero-docs.workers.dev (commit 2d81b43)

This URL reflects your latest Preview deployment

Preview Deployments by commit

Status	Deployment URL	Commit	Updated (UTC)	See this deployment's details
Build: Success ✅ Deployment: Success ✅ View logs ↗	https://91a4dc05-void-cloud.voidzero-docs.workers.dev	2d81b43	2026-10-27T07:55:08.574Z	Visit the dashboard ↗
Build: Success ✅ Deployment: Success ✅ View logs ↗	https://50ada90c-void-cloud.voidzero-docs.workers.dev	7748d0d	2026-10-27T07:20:40.787Z	Visit the dashboard ↗

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Delightful!

Reviewed commit: 7748d0d3e3

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".