Jest/Enzyme Transition Rejection/TypeError about react

[christopherthielen]

Sounds like you're running into this: facebook/react#15691
This is caused when async callbacks tell react to render a component after the test is torn down. Make sure your async tests are properly written.

it('async test', async () => {
  var wrapper = mount(<UIView/>);
  await someAsyncThing();
})

I'm not an expert on on react async testing, but you'll likely need to wrap some operations in act. I believe you may also need to wrap async operations in async act,

await act(async () => {
  asyncAction()
});

Finally, you can try to unmount your component at the end of your test:

wrapper.unmount()