Problem
Standard Schema validators can return issue objects that cannot be serialized with JSON.stringify. This hides the original validation failure.
The same raw serialization pattern exists in server-function validation and router search validation.
Scope
Create a shared internal formatter for Standard Schema issues and use it in both paths.
The formatter must:
Preserve issue messages.
Handle root and nested paths without ambiguous dot-path collisions.
Safely handle prototype-named keys such as __proto__.
Avoid adding a public router-core export unless there is a supported external use case.
Tests
Add unit coverage for root issues, nested paths, numeric keys, special property names, and non-serializable issue objects.
Add E2E coverage for server-function validation using multiple Standard Schema-compatible libraries, as requested in fix: extract props from validator issues #3708
Verify router search validation uses the same safe formatting behavior.
Run the relevant React Start bundle-size scenario.
Documentation
Review and update the validator documentation to describe Standard Schema compatibility and the resulting validation-error behavior where user-facing.
Related work
Supersedes stale #3708 which should be updated for the current validation architecture and cover both server-function and router search validation.
Problem
Standard Schema validators can return issue objects that cannot be serialized with
JSON.stringify. This hides the original validation failure.The same raw serialization pattern exists in server-function validation and router search validation.
Scope
Create a shared internal formatter for Standard Schema issues and use it in both paths.
The formatter must:
__proto__.router-coreexport unless there is a supported external use case.Tests
Documentation
Review and update the validator documentation to describe Standard Schema compatibility and the resulting validation-error behavior where user-facing.
Related work
Supersedes stale #3708 which should be updated for the current validation architecture and cover both server-function and router search validation.