--- You can send and receive messages to the server within 'Session' via 'getMessage',
--- 'sendRequest' and 'sendNotification'.
---
--- @
--- runSession \"path\/to\/root\/dir\" $ do
--- docItem <- getDocItem "Desktop/simple.hs" "haskell"
--- sendNotification TextDocumentDidOpen (DidOpenTextDocumentParams docItem)
--- diagnostics <- getMessage :: Session PublishDiagnosticsNotification
--- @
-type Session = ParserStateReader FromServerMessage SessionState SessionContext IO
+-- You can send and receive messages to the server within 'Session' via
+-- 'Language.Haskell.LSP.Test.message',
+-- 'Language.Haskell.LSP.Test.sendRequest' and
+-- 'Language.Haskell.LSP.Test.sendNotification'.
+
+newtype Session a = Session (ConduitParser FromServerMessage (StateT SessionState (ReaderT SessionContext IO)) a)
+ deriving (Functor, Applicative, Monad, MonadIO, Alternative)
+
+#if __GLASGOW_HASKELL__ >= 806
+instance MonadFail Session where
+ fail s = do
+ lastMsg <- fromJust . lastReceivedMessage <$> get
+ liftIO $ throw (UnexpectedMessage s lastMsg)
+#endif