We made a silly joke on Twitter yesterday (this is what Twitter is for, no?) about test doubles and that unfortunate moment when they inevitably surprise you. This prompted Shlomo Kraus to reach out and tell us about Mockshot. In brief: Imagine you could: Never manually write a mock again Have a guarantee that your mocks are always valid Sounds nice! It works by using Jest’s snapshot tests output to generate mocks to be used in other tests. This is purposeful coupling, which seems like it could backfire in the long-run. However, the team behind the library has been using it for over a year and are still singing its praises. For more on their experience creating and using it, read this.