addMethod.test.js

describe('addNumbers method ', () => {
  it('Should contain atleast one input ', () => {
    expect(addNumber(1,2)).toBe(3);
    expect(addNumber(1)).toBe(1);
  });
  it('Should throw an error is user doesnt input value ', () => {
    expect(addNumber).toThrow();
  })
  it('Should return the sum of numbers in the arguments ', () => {
    expect(addNumber(1,3)).toBe(4);
    expect(addNumber(2,3,5)).toBe(10);
    expect(addNumber(2,3,2,2,2,2)).toBe(13);
  })
  it('Should add the numbers in the arguments ', () => {
    expect(addNumber(1,3)).toBe(4);
    expect(addNumber(2,3,5)).toBe(10);
    expect(addNumber(2,3,2,2,2,2)).toBe(13);
  })
  it('Should check that the user inputs are numbers ', () => {
    expect(addNumber(true, false)).toBe('Input must be a number');
    expect(addNumber(' ', '1')).toBe('Input must be a number');
    expect(addNumber(2, '3')).toBe('Input must be a number');
    expect(addNumber('10', '2')).toBe('Input must be a number');
  }) 
})