Rails engines testing with logs

I am having trouble in understanding how can I check the logs for a test
inside of an engine. So My setup is the typical example, with a main app
and engine. Inside of the engine I have a dummy application(inside the
rspec folder) that I use to test my engine.

Now I am construction a lib file and would like to test it. This lib is
a
communication system to an API and I am getting problems when
communicating
but it’s weird since I have another application making the same requests
to
the same API and it works. So I wanted to check the logs for the
tests(so I
can see the request and the messages being passed to the API).

My first thought was to look for a log folder at the engine, which does
not
exist??? second I thought maybe the main application(just to clear that
out
of the way), obviously the logs there were not logging anything. Then I
thought it could make sense if the dummy application had some logs and
it
does. The test.log, but that does not log anything.

Now just as detail, I am running my tests with guard & rspec.

let me know if you have some light on this or any other thoughts that
could
help.

all the best,

Andre