error : ReactWrapper::state(“isOpen”) requires that `state` not be `null` or `undefined`

问题

Writing an unit test file and not able to Render Modal components. I am using jest and Enzyme REACTJS

Here is what I have used in previous files for testing

   describe("Component Test", () => {

beforeEach(() => (wrapper = mount(<BrowserRouter><Component{...baseProps} /></BrowserRouter>)));

    it("renders a modal portal", () => {
  const isOpen = wrapper.state("isOpen");
  const modalPortal = wrapper.find(".fullmodal");
 expect(isOpen).toBeTruthy;
  expect(modalPortal).toHaveLength(1);
  expect(toJson(wrapper)).toMatchSnapshot();

});

here is an example of render() with a Modal component

         <Modal isOpen={this.state.quickFilterModalOpen} style={descriptionModalStyle}>
      <div>
        <div className='fullmodal'>
          <div className='sidemodal_addnew_x' onClick={this.closeModal}>
            <FontAwesome name='xbutton' className='fa-times' />
          </div>
        </div>    

error: ReactWrapper::state("isOpen") requires that state not be null or undefined.

Goal is to be able to render Modal components

来源：https://stackoverflow.com/questions/54889810/error-reactwrapperstateisopen-requires-that-state-not-be-null-or-un