How to use the react-dom/test-utils.findRenderedDOMComponentWithClass function in react-dom

it('Should output a prev button', () => {
    const instance = getInstance();
    ReactTestUtils.findRenderedDOMComponentWithClass(instance, 'rs-icon-page-previous');
  });

it('Should render a button by toggleComponentClass={Button}', () => {
    const instance = ReactTestUtils.renderIntoDocument(
      
    );
    ReactTestUtils.findRenderedDOMComponentWithClass(instance, 'rs-btn');
  });
});

it('should have extra classes', () => {
      const newProps = { ...fakeProps, extraClasses: fakeExtraClasses.join(' ') };
      const component = TestUtils.renderIntoDocument();

      const row = TestUtils.findRenderedDOMComponentWithClass(component, 'react-grid-Row');
      fakeExtraClasses.forEach((c) => {
        const containsExtraClass = row.className.indexOf(c) > -1;
        expect(containsExtraClass).toBe(true);
      });
    });
  });

it('has correct item styles', () => {
    component = TestUtils.renderIntoDocument(<menu><div>An item</div></menu>);
    firstItem = TestUtils.findRenderedDOMComponentWithClass(component, 'bm-item-list').children[0];
    expect(firstItem.style.display).to.equal('block');
  });

it('accepts an optional burgerButtonClassName', () => {
      component = TestUtils.renderIntoDocument(<menu>);
      const button = TestUtils.findRenderedDOMComponentWithClass(component, 'bm-burger-button');
      expect(button.classList.toString()).to.contain('custom-class');
    });
</menu>

it('has correct item styles', () => {
    const firstItem = TestUtils.findRenderedDOMComponentWithClass(component, 'bm-item-list').children[0];
    expect(firstItem.style.display).to.equal('block');
  });

        assert.throws(() => TestUtils.findRenderedDOMComponentWithClass(field, 'focused'));

function renderTestApp () {
  const testApp = renderIntoDocument();
  const dropdown = findRenderedComponentWithType(testApp, Dropdown);
  const dropdownElement = findRenderedDOMComponentWithClass(dropdown, 'dropdown');
  const dropdownElementDomNode = findDOMNode(dropdownElement);
  const trigger = findRenderedComponentWithType(testApp, DropdownTrigger);
  const triggerElement = findRenderedDOMComponentWithClass(trigger, 'dropdown__trigger');
  const content = findRenderedComponentWithType(testApp, DropdownContent);
  const contentElement = findRenderedDOMComponentWithClass(content, 'dropdown__content');
  const contentElementDomNode = findDOMNode(contentElement);

  return {
    testApp,
    dropdown,
    dropdownElement,
    dropdownElementDomNode,
    trigger,
    triggerElement,
    content,
    contentElement,
    contentElementDomNode
  };
}

return (
            
              
            
          )
        }
      }
      const TestForm = reduxForm({ form: 'testForm' })(Form)
      const dom = TestUtils.renderIntoDocument(
        
          
        
      )

      const addButton = TestUtils.findRenderedDOMComponentWithClass(dom, 'add')
      const removeButton = TestUtils.findRenderedDOMComponentWithClass(
        dom,
        'remove'
      )
      TestUtils.Simulate.click(addButton)

      expect(store.getState()).toEqualMap({
        form: {
          testForm: {
            values: {
              foo: {
                bar: ['dog', 'cat', 'fish']
              }
            },
            registeredFields: {
              'foo.bar': { name: 'foo.bar', type: 'FieldArray', count: 1 },
              'foo.bar[0]': { name: 'foo.bar[0]', type: 'Field', count: 1 },

it('renders create input as an item when creating', () => {
      const items = ['1', '2', '3'];
      const list = makeList(items, { initialState: { creatingItem: true } });
      const createItem = findRenderedDOMComponentWithClass(list, 'create-item-input');
      expect(createItem).toBeDefined();
    });