Zod discriminated union does not work with dataType: 'form' even when data is not nested #655
Description
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Description
When using discriminated unions in Zod, setting the default values and converting the types only works with dataType set to 'json' even when the data is not nested.
As a result, without dataType set to 'json' you always get invalid input errors except for string fields. But even those don't work properly if they have a minimum length set. In that case, you receive an "invalid input" error instead of a "too small" from Zod when submitting an empty field.
If applicable, a MRE
This can be seen in the official discriminated-union example when submitting an extra type without providing a name. The error is "Invalid input: expected string, received undefined" when it should be "Too small: expected string to have >=1 characters". The desired result is only achieved with dataType set to 'json' when it should work with the default setting as well.
The issue is worse for non-string types since in those cases the type will never comply with the schema and you always receive errors even if the form was filled in correctly.
I have modified the official discriminated-union example to show this by adding an age prop of type number. Submitting the form gives an error and resets the field to 0.