type-fest/test-d/non-empty-object.ts

import {expectNever, expectType} from 'tsd';
import type {NonEmptyObject, RequireAtLeastOne} from '../index.d.ts';

type TestType1 = {
	a: string;
	b: boolean;
};

type TestType2 = {
	a?: string;
	b?: boolean;
};

type TestType3 = {
	a: string;
	b?: boolean;
};

type TestType4 = {};

declare const test1: NonEmptyObject<TestType1>;
declare const test2: NonEmptyObject<TestType2>;
declare const test3: NonEmptyObject<TestType3>;
declare const test4: NonEmptyObject<TestType4>;

expectType<TestType1>(test1);
expectType<RequireAtLeastOne<TestType2>>(test2);
expectType<TestType3>(test3);
expectNever(test4);