issue: data param in onValid in handleSubmit infers as any when TTransformedValues is a union type

[Ar4ys]

Version Number

7.49.3

Codesandbox/Expo snack

https://codesandbox.io/p/sandbox/youthful-chaplygin-4svfw9

Steps to reproduce

1. Go to CodeSandbox
2. Open /src/App.tsx file
3. In useTTransformedValues in handleSubmit (in line 9) you will see that:
   • data is inferred as any
   • as a result, TS shows an error: "Parameter 'data' implicitly has an 'any' type."

Expected behaviour

data should be inferred as Form (i.e. union type) - the same as in useOnlyTFieldValues (line 14)

What browsers are you seeing the problem on?

No response

Relevant log output

Parameter 'data' implicitly has an 'any' type.

Code of Conduct

• I agree to follow this project's Code of Conduct

[Ar4ys]

This issue happens because of Distributive Conditional Types feature in TypeScript. Specifically, because of how TTransformedValues is defined and used inside of UseFormHandleSubmit: github permalink.

There are two possible fixes I came up with:

1. Force TypeScript to avoid distributing conditional types "by surrounding each side of the extends keyword with square brackets" inside UseFormHandleSubmit (taken from TypeScript Handbook#Distributive Conditional Types)
2. Replace current UseFormHandleSubmit implementation with the one that relies on default values in generics:

// Proposed implementation of `UseFormHandleSubmit`
export type UseFormHandleSubmit<
  TFieldValues extends FieldValues,
  TTransformedValues extends FieldValues = TFieldValues,
> = (
  onValid: SubmitHandler<TTransformedValues>,
  onInvalid?: SubmitErrorHandler<TFieldValues>,
) => (e?: React.BaseSyntheticEvent) => Promise<void>;

The second solution should work in all use-cases, that current one covers without any drawbacks (at least I could not come up with any use-case that may break). As such I would like to create a PR with second fix applied, but as a safety measure I would like to know the reasoning behind current TTransformedValues and UseFormHandleSubmit implementation (maybe second fix actually breaks in some obscure edge case).

[bluebill1049]

Replace current UseFormHandleSubmit implementation with the one that relies on default values in generics:

Could you share a PR with the second approach?

[Ar4ys]

Here is PR #11420 with the second approach.