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 deea111f3e43006ce8084653b6e287b489950048..713b25f101a23429668a1f29207e8f2c4a63645e 100644 (file)
--- a/src/Language/Haskell/LSP/Test/Exceptions.hs
+++ b/src/Language/Haskell/LSP/Test/Exceptions.hs
@@ -1,10 +1,56 @@
 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
+
+-- | 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
 
-data SessionException = TimeoutException
-  deriving Show
 instance Exception SessionException
 
+instance Show SessionException where
+  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:\n" ++ B.unpack (encodePretty lastMsg)
+  show (ReplayOutOfOrder received expected) =
+    let expected' = nub expected
+        getJsonDiff = lines . B.unpack . encodePretty
+        showExp exp = B.unpack (encodePretty exp) ++ "\nDiff:\n" ++
+                ppDiff (getGroupedDiff (getJsonDiff received) (getJsonDiff exp))
+    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