TypeScript: How to write a function with conditional return type

Question

export type Name = { name: string }
export type Id = { id: number }
export type Value = T extends string ? Name : Id

export function create

        

Answer 1

I'm not sure I understand your example fully, but I think this is what you want?

type Name = { name: string }
type Id = { id: number }
type Value = Name | Id

export function create(value: string | number): Value {
  if (typeof value === "string") return { name: value }
  return { id: value }
}

See, that I've removed any generics from your example, since I don't see the need for them in this case