It would be cool if SignalSpy could examine the signal

There is a SingalSpy in qtest-qml. That is quite cool feature for monitoring for signals. Unfortunately everything it can do is to wait for a signal to be emitted. It is good enough if you use SignalSpy as just a "smart wait()", but not good enough if you want to verify the correctness of the signal being emitted.

I'd like to be able to verify whether captured signal contains correct parameters.

I guess the simplest way to achieve that would be to make a set of last captured signal arguments available in the SinglaSpy properties.
Or maybe it would be simpler to allow an instantiated SignalSpy actually process signal in whichever way makes sense for developer.