Separation between internal and submitted types

[supple quartz]

I think it would make sense for useForm({ defaultValue }) and field.handleChange to treat the value as Partial<> even if the field is required. That way defaultValue could specify only part of the type and handleChange could be called with undefined field.handleChange() to unset the field(e.g. for a file field)

[silver pivot]

totally agree. i have a form where i want a select field to be undefined by default, but the type makes it a required field of a union. I dont have to set the single select to one of the req. values since i want to force a user to select it and validate it

so im not sure how to

1. use defaultValues as partial
2. validate the form as a stricter type of the data, including any required fields

[chrome blade]

Doing so would fundamentally break the way our type inferencing works and cause an awful lot of headaches with most users:

https://github.com/TanStack/form/issues/705#issuecomment-2135943113

If you want to use defaultValues as a partial, then type cast it 🙂

[supple quartz]

Hmm. Seems incorrect. If there is no defaultValue provided then the type of state.value is not the same as useForm<X> (i.e. X). It can't be. Without defaultValue the correct typing of state.value is Partial<X>.

I wonder if a better solution would be to hold onto two types in the Form type useForm<X, InternalX>. Then something like zod could take InternalX and transform it into X. Partial isn't actually good enough because you don't want to have to deal with the case where prop x is X | undefined when you actually did provide a default value.