Experimenting with how to strongly type field renames

generic-rename-type.ts

interface Foo {
    a: string;
    b: number;
    c: {
        a: boolean[];
    }
}

type RenameAToZ<T> = T extends { a: any } ? {
    [K in keyof Omit<T, 'a'>]: RenameAToZ<T[K]>;
} & {
    z: T['a']
} : {
   [K in keyof Omit<T, 'a'>]: RenameAToZ<T[K]> 
};

type FooZ = RenameAToZ<Foo>;

const z: FooZ = {
    z: 'foo',
    b: 1,
    c: {
        z: [true]
    }
}