isEven = number => !(number % 2);isEven = number => number %2 === 0 ?true: number %1 === 0 ?false : undefined;- isEven = number => !(number % 2);
const expect = require("chai").expect; describe("Solution", function() { it("should be true for 4", function() { expect(isEven(4)).to.equal(true); }); it("should be false for 1", function() { expect(isEven(1)).to.equal(false); }); });- const expect = require("chai").expect;
- describe("Solution", function() {
- it("should be true for 4", function() {
- expect(isEven(4)).to.equal(true);
- });
- it("should be false for 1", function() {
- expect(isEven(1)).to.equal(false);
- });
it("should be undefined for 1.5", function() {expect(isEven(1.5)).to.equal(undefined);});it("should be undefined for NaN", function() {expect(isEven(NaN)).to.equal(undefined);});it("should be undefined for Infinity", function() {expect(isEven(Infinity)).to.equal(undefined);});it("should be undefined for -Infinity", function() {expect(isEven(NaN)).to.equal(undefined);});it("should be undefined for undefined", function() {expect(isEven(undefined)).to.equal(undefined);});- });