Adding happy path test

calculateFrame-3.test.js

test('it should return the sum of the rolls', () => {
  const firstRoll = 7 
  const secondRoll = 2 
  
  const frameScore = calculateFrame(firstRoll, secondRoll);
  
  expect(frameScore).toBe(9);
});

test('it should return the / sign if the players hit a spare', () => {
  const firstRoll = 7
  const secondRoll = 3

  const score = calculateFrame(firstRoll, secondRoll);
  expect(score).toBe('/');
});

test('it should return the X sign if the players hit a strike', () => {
  const firstRoll = 10
  const secondRoll = 0

  const score = calculateFrame(firstRoll, secondRoll);
  expect(score).toBe('X');
});