tdd-react-component-spec3.js

it('should have a user field', ()=>{
  expect(wrapper.find('.login__user[name="username"]').length).toBe(1);
});

it('should have a password field', ()=>{
  expect(wrapper.find('.login__password[name="password"][type="password"]').length).toBe(1);
});

it('should have a submit button', ()=>{
  expect(wrapper.find('.login__btn').length).toBe(1);
});

it('should disable the submit button by default', ()=>{
  expect(wrapper.find('.login__btn').prop('disabled')).toBe(true);
});