shouldNotBeAllowed.ts

type QueryValue = number | string | boolean | Date;

type Query<T> = {
  [P in SubTypeKeys<T, QueryValue>]?: T[P] | T[P][]
};

type SubTypeKeys<Base, Condition> = {
	[Key in keyof Base]: Base[Key] extends Condition ? Key : never
}[keyof Base];

class Foo {
  bar: string;
}

type Combination = number & {whatever: string};

const value: Combination = null;
const query: Query<Foo> = value; // Should not be allowed

type Example = {
    [P in ("a" | "b")]?: string
}

let opaqueType: number & { whatever: string };
let example: Example = opaqueType