How to use the enzyme.shallow function in enzyme

it('sets `inProgress` to true before resolving promise', (done) => {
    let wrapper = shallow();

    const promise = new Promise((resolve) => {
      // expect(wrapper.text()).toEqual('Loading...');
      resolve(42);
      expect(wrapper.find('button').exists()).toBe(true);
      done();
    });

    wrapper = wrapper.setProps({ promise });
    wrapper.find('button').simulate('click');
  });
});

it(`does not add any className when ${bool}`, () => {
      consoleUtil.disableOnce()

      const wrapper = shallow(React.createElement(Component, { ...requiredProps, [propKey]: bool }))

      wrapper.should.not.have.className(className)
      wrapper.should.not.have.className('true')
      wrapper.should.not.have.className('false')

      propValues.forEach(propVal => wrapper.should.not.have.className(propVal.toString()))
    }),
  )

test('wrapperClassName', () => {
  const component = shallow(render())
  expect(component.prop('className')).toBe('paragraph paragraph--xtight')
})

it('should be a Collapse', () => {
    const collapse = shallow(Yo!);

    expect(collapse.type()).toBe(Collapse);
  });

describe("tags on component", () => {
    let wrapper = shallow();

    it('include correct component, element and role data tags', () => {
      rootTagTest(wrapper, 'settings-row', 'bar', 'baz');
    });
  });
});

beforeEach(() => {
        props = createTestProps({
          columns: [{ key: '1', isFixed: true }, { key: '2' }],
        });
        wrapper = shallow();
        gridWrapper = shallow(
          wrapper.find(ClassNames).prop('children')({
            css: jest.fn(),
            cx: jest.fn(),
          })
        );
      });
      it('should not pass fixedColumnCount prop to ', () => {

it('should render with common props without exploding', () => {
    const wrapper = shallow();
    expect(wrapper).to.have.length(1);
    expect(wrapper.props().randomProp).to.be.equal('foo');
  });

it('should render nothing when tier prices are not available (field missing)', () => {
      const price = { currency: 'USD' };
      const wrapper = shallow();
      expect(wrapper).toBeEmptyRender();
    });
  });

function makeEventBox(
  events: protos.cockroach.server.serverpb.EventsResponse.IEvent[],
  refreshEventsFn: typeof refreshEvents,
) {
  return shallow(
    ,
  );
}