TYPESCRIPT

extend type typescript

type UserEvent = Event & {UserId: string}

extend typescript

interface Shape {
  color: string;
}
 
interface Square extends Shape {
  sideLength: number;
}
 
let square = {} as Square;
square.color = "blue";
square.sideLength = 10;
Try

typescript extend type

type Event = {
   name: string;
   dateCreated: string;
   type: string;
}

interface UserEvent extends Event {
   UserId: string; 
}