describe ('Sum of numbers Calculator', () => {


    // it('Should be an array', () => {

    //     expect().to.be.an('array');

    // });


    it('Should return the sum', () => {

       expect(sum([2, 3, 15])).to.be.an('number');

    });


    it('Should return the correct sum', () => {

        let expectedSum = 50;

        let actualSum = sum([10, 15, 20, 5]);

        expect(expectedSum).to.equal(actualSum);

    });

});