pass indicates whether there was a match or not, and message provides a function with no arguments that returns an error message in case of failure. You signed in with another tab or window. @rickhanlonii I figured out what it's doing. Running jest by default will find and run files located in a __tests__ folder or ending with .spec.js or .test.js.. Logging plain objects also creates copy-pasteable output should they have node open and ready. The exception cannot be trapped in any way from either the test code or the application code (I've tried putting try catch around the whole test to no avail. If you don't handle the rejection (a catch somewhere, or await ing it/returning it to jest), then yes, it's expected. yarn add --dev jest babel-jest @babel/preset-env @babel/preset-react react-test-renderer The package jest-fetch-mock gives us more control and avoids us having to handle the double promise response that fetch has. The module cache will only help caching the service clients under AWS namespace but when you construct the DynamoDB client, new operation objects will be attached to the client object. To resolve this, use the crossOriginLoading setting in development to add the crossorigin attribute to the