issue: `useTsController` eats `onChange(undefined)` and does not bubble it

[josiah-roberts]

Version Number

1.0.6

Codesandbox/Expo snack

No response

Steps to reproduce

1. Have an optional field
2. If you never touch it, the field value is unset (undefined)
3. Touch the field
4. You can now never set it back to undefined, because useTsController eats onChange(undefined)

This bug means that:

• If an optional field has never been touched, it's undefined
• If an optional field has been touched, the closest you can get to clearing it is setting it to null

Expected behaviour

Don't eat onChange(undefined). Forward it up to the passed onChange.

Relevant log output

No response