// ------------------- with generic type -------------------//
const extGenTypeFactory = <TObj extends Object>(specialObj: TObj) => {
    /**
     * Throws 'TS2312: An interface may only extend a class or another interface.'. 
     * Doesnt compile the stuff using the interfaces and themself
     */
    interface TExtObj extends TObj {
        newAttr: any
    }
    // works
    let newObj = specialObj;

    let extObj: TExtObj
    // This particular issue is Solved in 3.2, keeping it for understanding of the comment line
    // TS2698: 'Spread types may only be created from object types.'. 
    extObj = {
        ...specialObj,
        newAttr: "some other"
    }
    return extObj
}

// Tried to evade problem with suggestion from 'Why doesn't type inference work on this interface: interface Foo<T> { } ?'
const obj = extGenTypeFactory({ attr: "take that" })

// works fine
const genTypeFactory= <TObj>(specialObj: TObj) => {
    return specialObj;
}
// \------------------- with generic type -------------------//

// ------------------- with known type -------------------//
interface TObj extends Object {
    hasAttr: any
}
/**
 * Works fine.
 */
interface TExtObj extends TObj {
    newAttr: any
}
// \------------------- with known type -------------------//