Possible issue with UnpackNestedValue

Describe the bug I’m sorry if this is a bug/mistake on my side. I’m still catching up with TS and react-hook-form Seems that certain types are not handled well with UnpackNestedValue

To Reproduce Steps to reproduce the behavior:

import { useForm } from "react-hook-form";
import "./styles.css";

const testFunction = (query: Record<string, string | undefined | null>): void => {
  console.log(query)
};

export const Second = <T extends Record<string, string | undefined | null>>(): void => {
  const form = useForm<T>();

  const values = form.watch();
  testFunction(values)
}

Error:

Argument of type 'UnpackNestedValue<T>' is not assignable to parameter of type 'Record<string, string | null | undefined>'.
  Type 'NonUndefined<T> | (NonUndefined<T> extends Date | FileList ? T : NonUndefined<T> extends Record<string, unknown> ? { [K in keyof T]: UnpackNestedValue<...>; } : T)' is not assignable to type 'Record<string, string | null | undefined>'.
    Type 'NonUndefined<T> extends Date | FileList ? T : NonUndefined<T> extends Record<string, unknown> ? { [K in keyof T]: UnpackNestedValue<T[K]>; } : T' is not assignable to type 'Record<string, string | null | undefined>'.
      Type 'T | (NonUndefined<T> extends Record<string, unknown> ? { [K in keyof T]: UnpackNestedValue<T[K]>; } : T)' is not assignable to type 'Record<string, string | null | undefined>'.
        Type 'NonUndefined<T> extends Record<string, unknown> ? { [K in keyof T]: UnpackNestedValue<T[K]>; } : T' is not assignable to type 'Record<string, string | null | undefined>'.
          Type 'T | { [K in keyof T]: UnpackNestedValue<T[K]>; }' is not assignable to type 'Record<string, string | null | undefined>'.
            Type '{ [K in keyof T]: UnpackNestedValue<T[K]>; }' is not assignable to type 'Record<string, string | null | undefined>'.
              Type 'UnpackNestedValue<T[K]>' is not assignable to type 'string | null | undefined'.
                Type 'Record<string, unknown> | unknown[] | (NonUndefined<T[K]> extends Date | FileList ? T[K] : NonUndefined<T[K]> extends Record<string, unknown> ? { [K in keyof T[K]]: UnpackNestedValue<...>; } : T[K])' is not assignable to type 'string | null | undefined'.
                  Type 'Record<string, unknown>' is not assignable to type 'string'.
                    Type 'UnpackNestedValue<T[K]>' is not assignable to type 'string'.
                      Type 'Record<string, unknown> | unknown[] | (NonUndefined<T[K]> extends Date | FileList ? T[K] : NonUndefined<T[K]> extends Record<string, unknown> ? { [K in keyof T[K]]: UnpackNestedValue<...>; } : T[K])' is not assignable to type 'string'.
                        Type 'Record<string, unknown>' is not assignable to type 'string'.

Expected behavior

if I tweak UnpackNestedValue a bit error is gone.

export declare type UnpackNestedValue<T> = NonUndefined<T> extends NestedValue<infer U>
    ? U
    : NonUndefined<T> extends Date | FileList
        ? T
        : T extends Record<string, unknown> // change NonUndefined<T> to T
            ? {
                [K in keyof T]: UnpackNestedValue<T[K]>;
            }
            : T;

Additional context issue arrived with 6.x react-hook-form version

[parker45]

+1 to reopen this!

[k-one-o-two]

I’m using ^7.20.2 and facing the same error, can this please be reopened?