Type Alias UnionToIntersection<T>

UnionToIntersection: (T extends unknown ? (arg: T) => void : never) extends (
    arg: infer F,
) => void
    ? F
    : never

Converts a union type T into an intersection type.

type Inter = UnionToIntersection<{ a: string } | { b: number }>; // { a: string } & { b: number }