Wrong behavior of Curry generic

[valerii15298]

🐞 Bug Report

Thank you between for such a great Curry generic, I had read your post on medium(published about 2 years ago), and it is one of the most interesting, complex and beutiful typescript generics I had ever seen. Though I did not understand it fully yet.

I am trying to use Curry generic to type ramda's propOr function.

type propOrType = <D, O extends object, P extends string>(
    defaultValue: D,
    propName: P,
    obj: O,
) => D | (P extends keyof O ? O[P] : never);

declare const propOr: _.F.Curry<propOrType>;

const alice = {
    name: 'ALICE',
    age: 101,
};
let age = propOr('Default value', 'age', alice); // => '101'
// type of age is `unknown` but must be at least `string | number`

I expect type of 'age' to be 101 | 'Default value' or at least number | string but I am getting unknown type.