jest error: const warnedKeys: {[string]: boolean} = {}; - react-native

Question

If I run yarn test, which runs jest, I get the following error:
C:\react-native-project\node_modules\react-native\Libraries\Utilities\warnOnce.js:15
const warnedKeys: {[string]: boolean} = {};
But that only happens if I follow the directions of the react-native-testing-library:
Then automatically to add it to your jest tests by using setupFilesAfterEnv option in the
jest.config.js file:
If I remove the file I will not get that error and I can get simple tests to run. When I remove the file, the test runs but AsyncStorage is not recognized so the tests still don't run. I have AsyncStorage. It's installed and the app works, but I want to add component tests. I also noticed the file, jest.config.js, is conspicuously missing from the testing project itself. Is there any documentation or working example? I would rather not do a diff of my project and the testing project. Is there a more well-documented or reliable testing framework/module available?

Answer 1

I'm able to get working tests by following the documentation of the React Native Testing Library with the npm package name of #testing-library/react-native not to be confused with the React Native Testing Library with the npm package name of react-native-testing-library. Both packages allow testing components and are recommended by React-Native documentation but this one works when following the instructions. It also has instructions "to define a custom render method that includes things like global context providers, data stores, etc" so that testing components with AsyncStorage and such shouldn't be a problem.