import { isUndefined } from '../isUndefined'; import { describe, it, expect } from 'vitest'; describe('Tests isUndefined rule', () => { it('Should return true for `undefined` value', () => { expect(isUndefined(undefined)).toBe(true); expect(isUndefined()).toBe(true); }); it.each([ null, NaN, false, true, Object, Array(0), '', ' ', 0, 1, '0', '1', () => undefined, ])('Should return false for %s value', v => { expect(isUndefined(v)).toBe(false); }); });