NonEmptyArray.ts

type NonEmptyArray<T> = [T, ...T[]];

const okay: NonEmptyArray<number> = [1, 2];
const alsoOkay: NonEmptyArray<number> = [1];
const err: NonEmptyArray<number> = []; // error!

import { z } from "zod/v4";
const Foo = z.string().array().nonempty();
type Foo = z.infer<typeof Foo>;
const NonEmpty = z.tuple([z.string()], z.string());
type NonEmpty = z.infer<typeof NonEmpty>;
const array = Foo.parse([]);
console.log(array);