text: import caesar from './caesar';
  
  it('text is shifted with key = 1', () => {
    expect(caesar('abcd', 1)).toBe('bcde');
  });
  
  it('text is returned with key = 0 or empty', () => {
    expect(caesar('hello', 0)).toBe('hello');
    expect(caesar('there')).toBe('there');
  });
  
  it('text is wrapped', () => {
    expect(caesar('zoo', 1)).toBe('app');
  });
  
  it('text keeps the same case', () => {
    expect(caesar('ZoO', 2)).toBe('BqQ');
  });
  
  it('text keeps punctuation', () => {
    expect(caesar("Ohm, i don't know!", 1)).toBe("Pin, j epo'u lopx!");
  });
  
  it('returns an empty string with falsy params', () => {
    expect(caesar('')).toBe('');
    expect(caesar(null, null)).toBe('');
    expect(caesar()).toBe('');
  });
  