Expose ClientError type (#36)

* Expose the max receive message length channel argument + unittest

* `ClientError` GADT ctor => `ClientErrorResponse`, expose `ClientError`

Prior to this commit, the name `ClientError` was both:
  - The name of a data constructor name for the `ClientResult` GADT
  - A name of an internal sum type for capturing different kinds of client
    errors

We want to expose the latter to users of the library, and so expose the latter
and rename the former.

* Remove unused `MultiWayIf` lang ext

examples/echo/echo-hs/EchoClient.hs

@@ -44,5 +44,5 @@ main = do
         | rsp == expected             -> return ()
         | otherwise                   -> fail $ "Got unexpected response: '" ++ show rsp ++ "', expected: '" ++ show expected ++ "'"
       ClientNormalResponse _ _ _ st _ -> fail $ "Got unexpected status " ++ show st ++ " from call, expecting StatusOk"
-      ClientError e                   -> fail $ "Got client error: " ++ show e
+      ClientErrorResponse e           -> fail $ "Got client error: " ++ show e
   putStrLn $ "echo-client success: sent " ++ show pay ++ ", got " ++ show pay

src/Network/GRPC/HighLevel/Client.hs

@@ -13,15 +13,15 @@ module Network.GRPC.HighLevel.Client
   , StreamSend
   , WritesDone
   , LL.Client
-
   , ServiceClient
+  , ClientError(..)
   , ClientRequest(..)
   , ClientResult(..)
---  , ClientResponse, response, initMD, trailMD, rspCode, details
-
   , ClientRegisterable(..)
+  , clientRequest
+  )
 
-  , clientRequest ) where
+where
 
 import qualified Network.GRPC.LowLevel.Client as LL
 import qualified Network.GRPC.LowLevel.Call as LL
@@ -62,8 +62,7 @@ data ClientResult (streamType :: GRPCMethodType) response where
   ClientWriterResponse :: Maybe response -> MetadataMap -> MetadataMap -> StatusCode -> StatusDetails -> ClientResult 'ClientStreaming response
   ClientReaderResponse :: MetadataMap -> StatusCode -> StatusDetails -> ClientResult 'ServerStreaming response
   ClientBiDiResponse   :: MetadataMap -> StatusCode -> StatusDetails -> ClientResult 'BiDiStreaming response
-
+  ClientErrorResponse  :: ClientError -> ClientResult streamType response
-  ClientError  :: ClientError -> ClientResult streamType response
 
 class ClientRegisterable (methodType :: GRPCMethodType) where
   clientRegisterMethod :: LL.Client
@@ -92,30 +91,30 @@ clientRequest :: (Message request, Message response) =>
 clientRequest client (RegisteredMethod method) (ClientNormalRequest req timeout meta) =
     mkResponse <$> LL.clientRequest client method timeout (BL.toStrict (toLazyByteString req)) meta
   where
-    mkResponse (Left ioError_) = ClientError (ClientIOError ioError_)
+    mkResponse (Left ioError_) = ClientErrorResponse (ClientIOError ioError_)
     mkResponse (Right rsp) =
       case fromByteString (LL.rspBody rsp) of
-        Left err -> ClientError (ClientErrorNoParse err)
+        Left err -> ClientErrorResponse (ClientErrorNoParse err)
         Right parsedRsp ->
           ClientNormalResponse parsedRsp (LL.initMD rsp) (LL.trailMD rsp) (LL.rspCode rsp) (LL.details rsp)
 clientRequest client (RegisteredMethod method) (ClientWriterRequest timeout meta handler) =
     mkResponse <$> LL.clientWriter client method timeout meta (handler . convertSend)
   where
-    mkResponse (Left ioError_) = ClientError (ClientIOError ioError_)
+    mkResponse (Left ioError_) = ClientErrorResponse (ClientIOError ioError_)
     mkResponse (Right (rsp_, initMD_, trailMD_, rspCode_, details_)) =
       case maybe (Right Nothing) (fmap Just . fromByteString) rsp_ of
-        Left err -> ClientError (ClientErrorNoParse err)
+        Left err -> ClientErrorResponse (ClientErrorNoParse err)
         Right parsedRsp ->
           ClientWriterResponse parsedRsp initMD_ trailMD_ rspCode_ details_
 clientRequest client (RegisteredMethod method) (ClientReaderRequest req timeout meta handler) =
     mkResponse <$> LL.clientReader client method timeout (BL.toStrict (toLazyByteString req)) meta (\m recv -> handler m (convertRecv recv))
   where
-    mkResponse (Left ioError_) = ClientError (ClientIOError ioError_)
+    mkResponse (Left ioError_) = ClientErrorResponse (ClientIOError ioError_)
     mkResponse (Right (meta_, rspCode_, details_)) =
       ClientReaderResponse meta_ rspCode_ details_
 clientRequest client (RegisteredMethod method) (ClientBiDiRequest timeout meta handler) =
     mkResponse <$> LL.clientRW client method timeout meta (\_m recv send writesDone -> handler meta (convertRecv recv) (convertSend send) writesDone)
   where
-    mkResponse (Left ioError_) = ClientError (ClientIOError ioError_)
+    mkResponse (Left ioError_) = ClientErrorResponse (ClientIOError ioError_)
     mkResponse (Right (meta_, rspCode_, details_)) =
       ClientBiDiResponse meta_ rspCode_ details_

src/Network/GRPC/HighLevel/Generated.hs

@@ -32,6 +32,7 @@ module Network.GRPC.HighLevel.Generated (
   -- * Client
 , withGRPCClient
 , ClientConfig(..)
+, ClientError(..)
 , ClientRequest(..)
 , ClientResult(..)
 )

tests/TestClient.hs

@@ -39,7 +39,7 @@ testNormalCall client = testCase "Normal call" $
      res <- simpleServiceNormalCall client
               (ClientNormalRequest req 10 mempty)
      case res of
-       ClientError err -> assertString ("ClientError: " <> show err)
+       ClientErrorResponse err -> assertString ("ClientErrorResponse: " <> show err)
        ClientNormalResponse res _ _ stsCode _ ->
          do stsCode @?= StatusOk
             simpleServiceResponseResponse res @?= "NormalRequest"
@@ -60,7 +60,7 @@ testClientStreamingCall client = testCase "Client-streaming call" $
 
      (finalName, totalSum) <- readMVar v
      case res of
-       ClientError err -> assertString ("ClientError: " <> show err)
+       ClientErrorResponse err -> assertString ("ClientErrorResponse: " <> show err)
        ClientWriterResponse Nothing _ _ _ _ -> assertString "No response received"
        ClientWriterResponse (Just res) _ _ stsCode _ ->
          do stsCode @?= StatusOk
@@ -90,7 +90,7 @@ testServerStreamingCall client = testCase "Server-streaming call" $
             ClientReaderRequest (SimpleServiceRequest "Test" (fromList nums)) 10 mempty
               (\_ -> checkResults nums)
      case res of
-       ClientError err -> assertString ("ClientError: " <> show err)
+       ClientErrorResponse err -> assertString ("ClientErrorResponse: " <> show err)
        ClientReaderResponse _ sts _ ->
          sts @?= StatusOk
 
@@ -116,7 +116,7 @@ testBiDiStreamingCall client = testCase "Bidi-streaming call" $
      res <- simpleServiceBiDiStreamingCall client $
             ClientBiDiRequest 10 mempty (\_ -> handleRequests iterations)
      case res of
-       ClientError err -> assertString ("ClientError: " <> show err)
+       ClientErrorResponse err -> assertString ("ClientErrorResponse: " <> show err)
        ClientBiDiResponse _ sts _ ->
          sts @?= StatusOk
 
@@ -133,4 +133,3 @@ main = do
           , testServerStreamingCall service
           , testBiDiStreamingCall service ]) `finally`
          (simpleServiceDone service (ClientNormalRequest SimpleServiceDone 10 mempty))
-