Ban Props TS

banProps.ts

export type BanProps<T extends string> = { [P in T]: never } & {
  [key: string]: any;
};

interface Foo {
  x: string;
  y: number;
}

export type NotFoo = BanProps<keyof Foo>;

const n: NotFoo = {
  blarg: true, // Fine
  x: 'abc', // NO
  y: 4 // NO
};