Comment by bakemawaytoys
1 day ago
This is interesting; I see the docs mention that polling support is built in for asynchronous background tasks. What about event-driven systems where a message will be published when a task completes (such as from a message broker/pubsub system)?
There are really two separate concerns here.
The first is that some effect happens asynchronously, potentially interleaved with other operations. Whether a client observes completion by polling or by receiving an event from a message broker is orthogonal to the specification itself - the model looks essentially the same in both cases. The built-in test executor uses polling, but that's an execution strategy, not a specification construct.
If you have a trace containing both requests/responses and observed events, you can use the model to check that the trace conforms to the specification. In practice, it helps if the events can be localized to some interval in the execution (e.g. "this happened after A and before B"); otherwise the checker has to consider many more possible concurrent interleavings.
The conformance testing docs hint at how this can be done, but don't yet show an event-driven example. It's a good enough question that I'll write a dedicated doc page on it.
Conformance testing page: https://microsoft.github.io/accordant/docs/concepts/conforma...