This library contains functionality for writing unit tests for the "model" portion of your reflex-frp apps. Please see "test/Reflex/Test/SimpleHostSpec.hs" for basic usage example. You can find more usage examples in this project and this one.
Note that TriggerEvent class constraint is not supported. It could be added with some effort but breaks the "pureness" of the test (at least from its inputs) so I don't suggest it. You can still test parts of your network that don't require TriggerEvent.
There is also a monadic testing module in this library. You can see usage examples in "test/Reflex/Test/Monad/HostSpec.hs".
PRs are welcome. Perhaps you have some ideas to make the interface more useable.