import { isDateValid, isDateValidFn } from '../'; const validDate = '14/09/2019'; const invalidDate = '99/99/9999'; describe('isDateValid', () => { it('returns an error when the date is not valid', () => { expect(typeof isDateValid(invalidDate)).toBe('string'); }); it('returns true when the date is valid', () => { expect(isDateValid(validDate)).toBe(true); }); it('returns true if the value is falsy', () => { expect(isDateValid('')).toBe(true); }); it('works with custom error messages', () => { const rule = isDateValidFn({ default: 'test' }); expect(rule(invalidDate)).toBe('test'); }); });