Typescript how to create type with common properties of two types?

Question

There are 2 types

type A = {
  x: number
  y: number
}

type B = {
  y: number
  z: number
}

How to get type with common properties of that

Answer 1

Based on @kube's answer, you could use generics to create a reusable type:

type Common = {
    [P in keyof A & keyof B]: A[P] | B[P];
}

This allows you to create intersections on the fly:

const c: Common = { y: 123 };