I'm thinking about how to properly test AWS Step Functions. The problem is that I can either mock the entire response for every state in JSON only, or call out to a lambda. What I want is to type check the evaluated JSONPath payload and the mocked JSON response, to ensure that my tests always adheres to global contracts/types written in JSON Schema.

I think it's doable by dynamically creating lambdas based on test cases I define in one way or another, perhaps like mocked integration services, that does nothing but validate if the event from SFN matches a schema, and that the mocked response also matches a schema.

My concern is that I can't find prior projects doing this. My use case is mostly (exclusively at the moment) calling out to lambdas, so perhaps I can get away with this kind of type checking. But it's just weird that something like this doesn't already exist! Past experiences have taught me that if no one have tried it before, my idea is usually not that good.

Let me know what you think!

(Would have liked to use durable execution which totally solves the typing issue, but can't in this case)