System Test: optionally, don't fail on additional records.

[big-andy-coates]

topic expectations should be able to define if they are an exact list of records to expect, or a subset of records that must be produced, i.e. should a test fail on additional records?

This is potentially most usefully declared at the TopicExpectation level. However, need to think about the implications of this...

What if two expectations files cover the same topic and one does and one does not "fail on additional". Maybe this is OK if we inverse it to "swallow additional" rather than "fail on additional". Then if one swallows... additional are swallowed.

What if an expectation file doesn't define a top level topic name, but instead contains expected records from multiple topics. I guess if the expectation is configured to "swallow" then we'd swallow all topics references.

More thought required, but may be a useful enhancement to the suite level "additional records handling" customisation task, worth breaking out into a secondary follow on task.

[big-andy-coates]

Should the expectation ordering, currently define in the KafkaOptions class, also be defined at the TopicExpectation level instead?

[big-andy-coates]

The ks-connected-services-demo would benefit from updating to use this new option once its ready.

https://github.com/creek-service/ks-connected-services-demo