import isEven from '../isEven'; describe('isEven', () => { it('should detect if a number is even', () => { expect(isEven(0)).toBe(true); expect(isEven(2)).toBe(true); expect(isEven(-2)).toBe(true); expect(isEven(1)).toBe(false); expect(isEven(-1)).toBe(false); expect(isEven(-3)).toBe(false); expect(isEven(3)).toBe(false); expect(isEven(8)).toBe(true); expect(isEven(9)).toBe(false); expect(isEven(121)).toBe(false); expect(isEven(122)).toBe(true); expect(isEven(1201)).toBe(false); expect(isEven(1202)).toBe(true); }); });