YellowFlare.MessageProcessor.TestEngine (nuget): The TestEngine is built on top of the MessageProcessor-infrastructure and allows you to write BDD-style test cases. For each scenario, just create a test class that derives from the Scenario class and implement/override the Given- and When-methods. For each assertion you can then implement a Then-method.
Keywords: BDD|TDD|CQRS|DDD|MessageProcessor