Hi, I probably found a bug in TopologyTestDriver for quite non-trivial Kafka Streams topology.
The streaming logic is the following: There is a concept of children and parents. Children are aggregated under parent. Some children of master parent can send poison pills to other parents. Such parents die but already aggregated kids should go then to the master. Application remembers killed parents in a local store. If a new kid comes, the store is checked and then kid is rerouted to the master. I'm using intermediate topics in my topology as well as sometimes tombstones. Here is Gradle (Java 11 + Kotlin) based project which demonstrate the issue: https://github.com/czterocyty/kafka_streams_test_case You can see that few tests fail there as I expect that latest output Parent records have the latest generation. So seems that TopologyTestDriver does not care about the order of output records. Best regards, Adam Domański
