The following code just perfectly generates me a type that only allows existing hobbies:

const personWithHobby = [
    {
        name: "John",
        age: 30,
        hobby: "Football"
    },
    {
        name: "Doe",
        age: 24,
        hobby: "Soccer"
    }
] as const;

type Hobby = typeof personWithHobby[number]['hobby'];
let hobby: Hobby = 'Football';
//Does not work:
hobby = 'Tennis';

Now I need this type to be of the following type, too:

type Person = {
    name: string;
    age: number;
    doSomething: (v: string) => string;
};

My first attempt does not work since TS wants me to remove hobby:

const personWithHobby: Person[] = [
    {
        name: "John",
        age: 30,
        doSomething: v => v.length.toString(),
        //ts(2353) only known properties
        hobby: "Football"
    }
] as const;

Removing the type does work, but now the parameter type of doSomething can’t be resolved automatically:

const personWithHobby = [
    {
        name: "John",
        age: 30,
        //ts(7006) implicit any type
        doSomething: v => v.length.toString(),
        hobby: "Football"
    }
] as const;

I know I could allow implicit any, but I want the type to be known. Is it somehow possible to achieve both? Implicitly creating a new type based on the current one? So I can (again implicitly) have a type Hobby?