typescript use literals | string gives type as string

Issue

I'm writing a library, I have an object which I want to let the users of this library to get autocompletion on one of its properties, however I want them to be able to add other string too, my type is :

type Object2 = {
    prop: "*" | "line" | "media" | string;
}

On my IDE (Intellij) and also compile output I get :

Object2: {
    prop: string;
};

What I need to get however is the same as I defined "*" | "line" | "media" | string so what do I do I'm really stuck here

Solution

All string literal types get absorbed into string, because string is the base type of those literal types.

There is a way to prevent this, but intersecting string with {}

type Object2 = {
    prop: "*" | "line" | "media" | (string & {});
}

Playground Link

Any string will still be assignable to the prop, but you will get suggestions in VS Code.

This is discussed here. The &{} solution is also suggested there.

Answered By - Titian Cernicova-Dragomir