[FieldError] - unexpected type error for Date property which is not nullable

[I3enito]

Version Number

7.33.1

Codesandbox/Expo snack

https://codesandbox.io/s/recursing-jang-9l8kqm?file=/src/App.tsx

Steps to reproduce

1. Go to https://codesandbox.io/s/recursing-jang-9l8kqm?file=/src/App.tsx
2. Check the App.tsx and check the type error for the mandatoryDateError

Expected behaviour

After upgrading to version 7.33.1 I got TS-errors because my DateInput expect a FieldError regardless if the Date is nullable or not. This is not an urgent issue but I thought it might be a edge case which has been discovered. Or perhaps I just don't understand why this behaviour makes sense.

Thanks for your work and the awesome library!

What browsers are you seeing the problem on?

No response

Relevant log output

No response

Code of Conduct

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

[bluebill1049]

thanks for the issure report, type undefined is not assignable to FieldError https://codesandbox.io/s/focused-noyce-neh1zj?file=/src/App.tsx the latest update eliminated the need to use NestedValue to differentiate a nested object input vs a group of inputs. https://react-hook-form.com/ts#NestedValue This is a huge improvement for some use cases, as developers will no longer to implemented the NestedValue type anymore, however it does bring some limitations,s and moving forward I think it's worth taking those trade-offs, such as discriminating unions and perhaps your specific usage above as well. This will most likely not be reverted and moving forward to bring feature such as rules for useFieldArray.

[I3enito]

Thanks for the response. I honestly cannot completely follow your explanation as I didn't use NestedValue but that's fine. I was just surprised that there was another type generated for the error when using a Date. My solution is to just expect this type as well for my DateInput component.

interface InputDateProps<T> {
    className?: string
    type: 'date' | 'time'
    register: UseFormRegister<T>
    isDirty?: boolean
    defaultValue?: string
    label: string
    name: Path<T>
    required?: boolean
    error?: Merge<FieldError, FieldErrorsImpl<DeepRequired<Date>>> | FieldError
}

[bluebill1049]

It's not that you are using NestedValue, the change was made so users don't have to use NestedValue anymore. related PR: https://github.com/react-hook-form/react-hook-form/pull/8527/files I will take a look at the issue this weekend and see if we can improve or else you will have to use the work around which you have provided above. 🙏