Sending messages end to end (#21)

* duplex connection end-to-end (working, debug logs)

* agent: send, receive, acknowledge messages

* logging proposal

* logging: client/server (dis)connections

* agent scenario testing framework

* add tests, remove logs

* clean up

tests/SMPClient.hs

@@ -26,7 +26,7 @@ testSMPClient :: MonadUnliftIO m => (Handle -> m a) -> m a
 testSMPClient client = do
   threadDelay 5000 -- TODO hack: thread delay for SMP server to start
   runTCPClient testHost testPort $ \h -> do
-    line <- getLn h
+    line <- liftIO $ getLn h
     if line == "Welcome to SMP v0.2.0"
       then client h
       else error "not connected"
@@ -40,18 +40,25 @@ cfg =
       msgIdBytes = 6
     }
 
+withSmpServerOn :: (MonadUnliftIO m, MonadRandom m) => ServiceName -> m a -> m a
+withSmpServerOn port =
+  E.bracket
+    (forkIO $ runSMPServer cfg {tcpPort = port})
+    (liftIO . killThread)
+    . const
+
 withSmpServer :: (MonadUnliftIO m, MonadRandom m) => m a -> m a
-withSmpServer = E.bracket (forkIO $ runSMPServer cfg) (liftIO . killThread) . const
+withSmpServer = withSmpServerOn testPort
 
 runSmpTest :: (MonadUnliftIO m, MonadRandom m) => (Handle -> m a) -> m a
 runSmpTest test = withSmpServer $ testSMPClient test
 
 runSmpTestN :: forall m a. (MonadUnliftIO m, MonadRandom m) => Int -> ([Handle] -> m a) -> m a
-runSmpTestN nClients test = withSmpServer $ run [] nClients
+runSmpTestN nClients test = withSmpServer $ run nClients []
   where
-    run :: [Handle] -> Int -> m a
-    run hs 0 = test hs
-    run hs n = testSMPClient $ \h -> run (h : hs) (n - 1)
+    run :: Int -> [Handle] -> m a
+    run 0 hs = test hs
+    run n hs = testSMPClient $ \h -> run (n - 1) (h : hs)
 
 smpServerTest :: RawTransmission -> IO RawTransmission
 smpServerTest cmd = runSmpTest $ \h -> tPutRaw h cmd >> tGetRaw h