Testing Apollo Federated services

Hey guys, how would you go about testing apollo federated services ? I want to write e2e tests, but not sure where to begin? Is it possible to write out e2e test for separate service, or should I write these tests in my gateway? Since I have schemas that come from other services/subgraphs. Does someone have some experience with it and could tell me more? Would appreciate any help and tips. Looking forward for your reply

The idea is to keep the business/domain logic away from the gateway. Each federated service can house the e2e tests for the queries that it serves. These e2e tests are run against the gateway end-point. So, you don’t have to worry about the federated/extended types.

Do you mean that I should start all my microservices, start my gateway, and in my tests run the direct connection to my gateway? Isn’t that a bad practice? Did I get your idea right? If no could you expand a bit more? If yes- is it the best approach at the moment? Maybe you already have/could provide some small example of your approach? :>

Usually, E2E tests are run against an already deployed server/endpoint to test the entire flow including the dependencies (like other servers, databases, etc)

In a federated environment, if one of your services (serviceA) serves query1, and query2, you would write e2e tests for both the queries within serviceA's codebase and have then run against the gateway endpoint in the test/stage environment.

Take a look at the Testing GraphQL talk where Jake Dawkins talks about Unit, Integration, and E2E test implementation in the fullstack-tutorial repo. Hope this helps.