Type Alias CustomValidator

CustomValidator: (
value: FieldValue,
context: CustomValidatorContext,
) => string | null

Synchronous validator registered by name and referenced from field schemas.

Return a human-readable error message when invalid, or null when valid.

Type Declaration

- (value: FieldValue, context: CustomValidatorContext): string | null
- Parameters
  - value: FieldValue
  - context: CustomValidatorContext
  Returns string | null