Can't extend Zod object contain refine function

[Abdel-Monaam-Aouini]

https://codesandbox.io/s/bold-rgb-979c5f?file=/src/App.tsx

[colinhacks]

Indeed, this is a bit of a design flaw with how refinements are currently handled. I'm looking into a fix for Zod 4 because this would be a breaking change.

[dosubot]

Hi, @Abdel-Monaam-Aouini. I'm Dosu, and I'm helping the Zod team manage their backlog. I'm marking this issue as stale.

Issue Summary:

• You reported a problem with extending a Zod object that includes a refine function.
• @colinhacks acknowledged this as a design flaw and mentioned a potential fix in Zod 4.
• The issue received positive reactions, indicating community interest.

Next Steps:

• Please let me know if this issue is still relevant to the latest version of Zod. You can keep the discussion open by commenting here.
• If no updates are provided, the issue will be automatically closed in 7 days.

Thank you for your understanding and contribution!

[colinhacks]

Fixed in Zod 4, the original code now works - sort of. Calling .partial, .pick, .omit etc will wipe away all the refinements defined on the original object. The original refinement function assumes a certain known input type. These methods change the input type, so the implementation of the refinement function may no longer be valid. So it would be unsound to include those refinements.