Zod discriminated union ts issues

[dragansavevski]

Which project does this relate to?

Router

Describe the bug

When trying to have a zod discriminated union I cannot achieve full type safety. See the example app (__root.tsx and about.tsx). Basically I tried 3 approaches. Setting the undesired parameters to undefined, never and omitting them. Each of these approaches causes a different error:

1. If I use z.never type issues occur at About 2 link
2. If I use z.undefined type issues in the search middleware in the about route
3. If I omit them and not have them at all the loader cannot be typed.

Your Example Website or App

https://stackblitz.com/edit/tanstack-router-qm8eay?file=src%2Froutes%2F__root.tsx,src%2Froutes%2Fabout.tsx&preset=node

Steps to Reproduce the Bug or Issue

See the about.tsx component and its search params.
See the about.tsx component and the links inside.

Expected behavior

I expect to have a proper discriminated union type.

Screenshots or Videos

No response

Platform

• OS: macOS
• Browser: Chrome
• Version: 131.0.6778.86

Additional context

No response