content: import chai, { expect } from 'chai'
  import chaiEnzyme from 'chai-enzyme'
  import React from 'react'
  import { shallow } from 'enzyme'
  import sinon from 'sinon'
  
  import StartButton from './StartButton'
  
  chai.use(chaiEnzyme())
  
  describe('<StartButton />', () => {
    const onClickFn = sinon.spy()
    const wrapper = shallow(<StartButton onClickFn={onClickFn} />)
  
    it('Should render appropriately', () => {
      expect(wrapper.find('.button-start'))
        .to.have.length(1, '<StartButton /> does not display one start button')
    })
  
    it('Should start quiz on button click', () => {
      wrapper.find('.button-start').simulate('click')
      expect(onClickFn.calledOnce)
        .to.equal(true, 'button.button-start not clicked once')
    })
  })
  