Use an interface (Typescript 2.2+)
We can extend types in Typescript by using the extends keyword For example we can write:
type Profile = {
name: string,
email: string,
created_at: string | Date,
updated_at: string | Date
}
interface UserProfile extends User {
user_id: number
}
Use an intersection type
type UserProfile = Profile & { user_id: number }