Testing React components that fetches data using Hooks
Solution 1:
That issue is caused by many updates inside Component.
I got the same issue, this would solve the issue.
await act( async () => mount(<App />));
Solution 2:
Enzyme doesn't have support for hooks since it's a relatively new feature: https://github.com/airbnb/enzyme/issues/2011
Maybe you can use plain Jest in the meantime? Also don't worry about the warning, it's supposed to go away when React 16.9.0 is released (see this pull request https://github.com/facebook/react/pull/14853)