Nested parallel routes slot rendered after navigating back

[jer-k]

Link to the code that reproduces this issue

https://github.com/jer-k/graphql-rsc-dashboard

To Reproduce

Same issue as #60541 but that is closed and can't be commented on anymore. Tagging @ztanner as I hope this reproduction helps #60541 (comment)

I came across the above issue as I was searching around to try to understand why the slot isn't falling back to the default on subsequent navigation.

In my repository above

• Start on the home page (/)
  • You will see in the logs rendering in default { params: {}, searchParams: {} } from default.tsx#4
• Click the RSC (No Delay) button in the header to navigate to /books
  • You will see in the logs rendering in @breadcrumbs / BreadcrumbSlot [ 'books' ] from page.tsx#11
• Click Home in the header
  • No log from either the default.tsx or page.tsx shows up. The breadcrumbs still show Home | books instead of just Home.

Current vs. Expected behavior

• Current: Navigation to a page that does not match a path in the slot does not revert back to the default
• Expected: Navigation to a page that does not match path in the slot reverts back to the default

Provide environment information

npx --no-install next info

Operating System:
  Platform: darwin
  Arch: x64
  Version: Darwin Kernel Version 21.6.0: Sat Jun 18 17:07:25 PDT 2022; root:xnu-8020.140.41~1/RELEASE_X86_64
  Available memory (MB): 16384
  Available CPU cores: 12
Binaries:
  Node: 20.10.0
  npm: 10.2.3
  Yarn: 1.22.19
  pnpm: 9.0.6
Relevant Packages:
  next: 15.0.0-rc.0 // Latest available version is detected (15.0.0-rc.0).
  eslint-config-next: 14.2.3
  react: 19.0.0-rc-6f23540c7d-20240528
  react-dom: 19.0.0-rc-6f23540c7d-20240528
  typescript: 5.4.5
Next.js Config:
  output: N/A

### Which area(s) are affected? (Select all that apply)

Parallel & Intercepting Routes

### Which stage(s) are affected? (Select all that apply)

next dev (local)

### Additional context

_No response_

[ztanner]

Hi @jer-k -- this is expected behavior with catch-all routes.

A catch-all route will match all routes except for the "index" route that it's defined in. Meaning /foo, /bar, /foo/bar, ...etc, but not /.

With parallel routes, during a soft navigation (ie when clicking a Link) the router will attempt to match the page to a corresponding parallel route. If one doesn't exist, it'll keep whatever was previously in that slot, until you refresh the page. You can learn about that behavior here.

For your use-case, since you want the index route to render the same component as your catch-all component, you could add a @breadcrumbs/page.tsx that simply does:

export { default } from "./default";

(Or it could be the catch-all component if you prefer -- either one).

We have a task to support optional catch-all routes (ie [[...catchAll]]) which also matches the index. That issue is being tracked here: #61206

[jer-k]

Awesome, thank you for the info! Works perfectly using @breadcrumbs/page.tsx

[github-actions]

This closed issue has been automatically locked because it had no new activity for 2 weeks. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.