Type Alias PropertiesOfType<E, T>

PropertiesOfType<E, T>: keyof {
    [Property in keyof Exactify<E> as [T] extends [never]
        ? [NonNullable<E[Property]>] extends [never]
            ? Property
            : never
        : [NonNullable<E[Property]>] extends [never]
            ? never
            : NonNullable<E[Property]> extends T
                ? Property
                : never]: never
}

Returns the properties of Entity E of types that extend type T. Ignores undefined types.