Pretty print last received messages

[lsp-test.git] / src / Language / Haskell / LSP / Test / Exceptions.hs

diff --git a/src/Language/Haskell/LSP/Test/Exceptions.hs b/src/Language/Haskell/LSP/Test/Exceptions.hs
index 28903dc76d46ea1d9a4a9c2d7b5202793beeb8f7..713b25f101a23429668a1f29207e8f2c4a63645e 100644 (file)
--- a/src/Language/Haskell/LSP/Test/Exceptions.hs
+++ b/src/Language/Haskell/LSP/Test/Exceptions.hs
@@ -3,28 +3,37 @@ module Language.Haskell.LSP.Test.Exceptions where
 import Control.Exception
 import Language.Haskell.LSP.Messages
 import Language.Haskell.LSP.Types
+import Data.Aeson
 import Data.Aeson.Encode.Pretty
 import Data.Algorithm.Diff
 import Data.Algorithm.DiffOutput
 import Data.List
 import qualified Data.ByteString.Lazy.Char8 as B
 
-data SessionException = Timeout
+-- | An exception that can be thrown during a 'Haskell.LSP.Test.Session.Session'
+data SessionException = Timeout (Maybe FromServerMessage)
+                      | NoContentLengthHeader
                       | UnexpectedMessage String FromServerMessage
                       | ReplayOutOfOrder FromServerMessage [FromServerMessage]
                       | UnexpectedDiagnostics
                       | IncorrectApplyEditRequest String
                       | UnexpectedResponseError LspIdRsp ResponseError
+                      | UnexpectedServerTermination
   deriving Eq
 
 instance Exception SessionException
 
 instance Show SessionException where
-  show Timeout = "Timed out waiting to receive a message from the server."
+  show (Timeout lastMsg) =
+    "Timed out waiting to receive a message from the server." ++
+    case lastMsg of
+      Just msg -> "\nLast message received:\n" ++ B.unpack (encodePretty msg)
+      Nothing -> mempty
+  show NoContentLengthHeader = "Couldn't read Content-Length header from the server."
   show (UnexpectedMessage expected lastMsg) =
     "Received an unexpected message from the server:\n" ++
     "Was parsing: " ++ expected ++ "\n" ++
-    "Last message received: " ++ show lastMsg
+    "Last message received:\n" ++ B.unpack (encodePretty lastMsg)
   show (ReplayOutOfOrder received expected) =
     let expected' = nub expected
         getJsonDiff = lines . B.unpack . encodePretty
@@ -33,12 +42,15 @@ instance Show SessionException where
     in "Replay is out of order:\n" ++
        -- Print json so its a bit easier to update the session logs
        "Received from server:\n" ++ B.unpack (encodePretty received) ++ "\n" ++
+       "Raw from server:\n" ++ B.unpack (encode received) ++ "\n" ++
        "Expected one of:\n" ++ unlines (map showExp expected')
   show UnexpectedDiagnostics = "Unexpectedly received diagnostics from the server."
   show (IncorrectApplyEditRequest msgStr) = "ApplyEditRequest didn't contain document, instead received:\n"
                                           ++ msgStr
   show (UnexpectedResponseError lid e) = "Received an exepected error in a response for id " ++ show lid ++ ":\n"
                                           ++ show e
+  show UnexpectedServerTermination = "Language server unexpectedly terminated"
 
+-- | A predicate that matches on any 'SessionException'
 anySessionException :: SessionException -> Bool
 anySessionException = const True