basic_component_test.spec.js

describe('Basic component', () => {
  describe('Lifecycle', () => {
    it('Mounted', done => {
      const handleScrollStub = sinon.stub(BasicComponent.methods, 'handleScroll')
      const addEventStub = sinon.stub(window, 'addEventListener')
      
      const wrapper = mount(BasicComponent)

      expect(addEventStub).to.be.calledWith('scroll', wrapper.vm.handleScroll)

      handleScrollStub.restore()
      addEventStub.restore()
      done()
    })

    it('Destroyed', done => {
      const wrapper = mount(BasicComponent)
      const handleScrollStub = sinon.stub(wrapper.vm, 'handleScroll')
      const removeEventStub = sinon.stub(window, 'removeEventListener')

      wrapper.destroy()

      expect(removeEventStub).to.be.calledWith('scroll', wrapper.vm.handleScroll)

      handleScrollStub.restore()
      removeEventStub.restore()
      done()
    })
  })
})