Safe way to extract property names

In TS 2.1 the keyof keyword was introduced which made this possible:

function propertyOf<TObj>(name: keyof TObj) {
    return name;
}

or

function propertiesOf<TObj>(_obj: (TObj | undefined) = undefined) {
    return function result<T extends keyof TObj>(name: T) {
        return name;
    }
}

or using Proxy

export function proxiedPropertiesOf<TObj>(obj?: TObj) {
    return new Proxy({}, {
        get: (_, prop) => prop,
        set: () => {
        throw Error('Set not supported');
        },
    }) as {
        [P in keyof TObj]?: P;
    };
}

These can then be used like this:

propertyOf<MyInterface>("myProperty");

or

const myInterfaceProperties = propertiesOf<MyInterface>();
myInterfaceProperties("myProperty");

or

const myInterfaceProperties = propertiesOf(myObj);
myInterfaceProperties("myProperty");

or

const myInterfaceProperties = proxiedPropertiesOf<MyInterface>();
myInterfaceProperties.myProperty;

or

const myInterfaceProperties = proxiedPropertiesOf(myObj);
myInterfaceProperties.myProperty;