TypeScript require one parameter or the other, but not neither

Question

Say I have this type:

export interface Opts {
  paths?: string | Array,
  path?: string | Array

        

Answer 1

You may use

export type Opts = { path: string | Array } | { paths: string | Array }

To increase readability you may write:

type StringOrArray = string | Array;

type PathOpts  = { path : StringOrArray };
type PathsOpts = { paths: StringOrArray };

export type Opts = PathOpts | PathsOpts;