Typescript: Is there a union of string literal types for the output of typeof?

Question

I'm aware that the output type of typeof is a string.

In typescript there's this pattern, called a "Union of string literal types":

export type Fruit = 'banana' | 'apple' | 'orange';

Q: Is there an importable union of string literal types that exists in any library allowing one to ensure a field can only be a possible output of the typeof operator?

Example psuedoish code:

import {JSType} from '@somelib/types'; // <--- what I want, this is a bogus type/lib

export class SomeClass {
    data: any;
    type: JSType;
    constructor (params) {
        this.data = params.data;
        this.type = typeof params.data;
    }
    render = () => {
        switch(this.type){
            case 'boolean':
                // return checkbox html component
            // more type cases
            default:
                // return input html component
        }
    }
}

I could manually create the type I need, but I'd prefer to let someone smarter than me handle the maintenance of the type, and future proof if JS/TS ever adds some type besides 'string' | 'number' | 'function' | 'object' | 'undefined'.

Also, in a pinch if I need to add a custom type, then I can just extend the existing type, to include the strings I need.

Edit #1: Updated terminology. Thanks to jcalz

Answer 1

There has to be a better way to do this, seeing as those definitions already exist somewhere. But we can access the union in a very roundabout way by:

• creating a variable with type any
• calling JS typeof on that variable, which will return the union of all possible types
• creating a typescript type that uses TS typeof to access that union as a type.

const x: any = "";

const t = typeof x;

type TypeofTypes = typeof t;

This creates

type TypeofTypes = "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"

Typescript Playground Link