Refactor error handling and fix most warnings

src/Network/Minio.hs

@@ -25,7 +25,7 @@ import System.FilePath
 import qualified Data.Conduit as C
 import qualified Data.Conduit.Binary as CB
 
-import Lib.Prelude
+-- import Lib.Prelude
 
 import Network.Minio.Data
 import Network.Minio.S3API

src/Network/Minio/API.hs

@@ -13,6 +13,7 @@ import qualified Network.HTTP.Types as HT
 import           Network.HTTP.Conduit (Response)
 import qualified Network.HTTP.Conduit as NC
 import           Network.HTTP.Types (Method, Header, Query)
+import qualified Data.ByteString.Lazy as LBS
 
 import           Lib.Prelude
 
@@ -59,19 +60,31 @@ buildRequest ri = do
     , NC.requestBody = NC.RequestBodyBS pload
     }
 
+isFailureStatus :: Response body -> Bool
+isFailureStatus resp = let s = HT.statusCode (NC.responseStatus resp)
+                       in not (s >= 200 && s < 300)
+
 executeRequest :: RequestInfo -> Minio (Response LByteString)
 executeRequest ri = do
   req <- buildRequest ri
   mgr <- asks mcConnManager
-  NC.httpLbs req mgr
+  resp <- NC.httpLbs req mgr
+  if (isFailureStatus resp)
+    then throwError $ MErrService $ LBS.toStrict $ NC.responseBody resp
+    else return resp
+
 
 mkStreamRequest :: RequestInfo
                 -> Minio (Response (C.ResumableSource Minio ByteString))
 mkStreamRequest ri = do
   req <- buildRequest ri
   mgr <- asks mcConnManager
+  resp <- NC.http req mgr
+  if (isFailureStatus resp)
+    then do errResp <- NC.lbsResponse resp
+            throwError $ MErrService $ LBS.toStrict $ NC.responseBody errResp
+    else return resp
 
-  NC.http req mgr
 
 requestInfo :: Method -> Maybe Bucket -> Maybe Object
             -> Query -> [Header] -> Payload

src/Network/Minio/Data.hs

@@ -15,18 +15,16 @@ module Network.Minio.Data
   , runMinio
   , defaultConnectInfo
   , connect
-  , Payload(..)
+  , Payload
   , s3Name
   ) where
 
 import qualified Data.ByteString as B
-import qualified Data.Conduit as C
 import           Network.HTTP.Client (defaultManagerSettings, HttpException)
-import           Network.HTTP.Types (Method, Header, Query, Status)
+import           Network.HTTP.Types (Method, Header, Query)
 import qualified Network.HTTP.Conduit as NC
 
-import Control.Monad.Trans.Class (MonadTrans(..))
-import Control.Monad.Trans.Resource (MonadThrow, MonadResource, ResourceT, ResIO)
+import Control.Monad.Trans.Resource (MonadThrow, MonadResource, ResourceT)
 import Control.Monad.Base (MonadBase(..))
 
 import Text.XML
@@ -79,9 +77,10 @@ getPathFromRI ri = B.concat $ parts
 getRegionFromRI :: RequestInfo -> Text
 getRegionFromRI ri = maybe "us-east-1" identity (riRegion ri)
 
-data MinioErr = MErrMsg ByteString
-              | MErrHttp HttpException
-              | MErrXml ByteString
+data MinioErr = MErrMsg ByteString -- generic
+              | MErrHttp HttpException -- http exceptions
+              | MErrXml ByteString -- XML parsing/generation errors
+              | MErrService ByteString -- error response from service
   deriving (Show)
 
 newtype Minio a = Minio {

src/Network/Minio/S3API.hs

@@ -13,16 +13,12 @@ import qualified Data.Conduit as C
 
 import           Lib.Prelude
 
-import qualified Data.ByteString.Lazy as LBS
 
 import           Network.Minio.Data
 import Network.Minio.API
 import Network.Minio.XmlParser
 import Network.Minio.XmlGenerator
 
-status204 :: HT.Status
-status204 = HT.Status{ HT.statusCode = 204, HT.statusMessage = "No Content" }
-
 getService :: Minio [BucketInfo]
 getService = do
   resp <- executeRequest $
@@ -40,37 +36,23 @@ getObject :: Bucket -> Object -> HT.Query -> [HT.Header]
           -> Minio ([HT.Header], C.ResumableSource Minio ByteString)
 getObject bucket object queryParams headers = do
   resp <- mkStreamRequest reqInfo
-  let httpStatusCode = HT.statusCode $ NC.responseStatus resp
-  if httpStatusCode >= 200 && httpStatusCode < 300
-    then return $ (NC.responseHeaders resp, NC.responseBody resp)
-    else do errMsg <- NC.lbsResponse resp
-            throwError $ MErrXml $ LBS.toStrict $ NC.responseBody errMsg
+  return $ (NC.responseHeaders resp, NC.responseBody resp)
   where
     reqInfo = requestInfo HT.methodGet (Just bucket) (Just object)
               queryParams headers Nothing
 
 putBucket :: Bucket -> Location -> Minio ()
 putBucket bucket location = do
-  resp <- executeRequest $
+  void $ executeRequest $
     requestInfo HT.methodPut (Just bucket) Nothing [] [] $
     Just $ mkCreateBucketConfig bucket location
 
-  let httpStatus = NC.responseStatus resp
-  when (httpStatus /= HT.ok200) $
-    throwError $ MErrXml $ LBS.toStrict $ NC.responseBody resp
-
 deleteBucket :: Bucket -> Minio ()
 deleteBucket bucket = do
-  resp <- executeRequest $
+  void $ executeRequest $
     requestInfo HT.methodDelete (Just bucket) Nothing [] [] Nothing
-  let httpStatus = NC.responseStatus resp
-  when (httpStatus /= status204) $
-    throwError $ MErrXml $ LBS.toStrict $ NC.responseBody resp
 
 deleteObject :: Bucket -> Object -> Minio ()
 deleteObject bucket object = do
-  resp <- executeRequest $
+  void $ executeRequest $
     requestInfo HT.methodDelete (Just bucket) (Just object) [] [] Nothing
-  let httpStatus = NC.responseStatus resp
-  when (httpStatus /= status204) $
-    throwError $ MErrXml $ LBS.toStrict $ NC.responseBody resp