Fix hlint warnings and suggestions (#44)

src/Network/Minio.hs

@@ -134,7 +134,7 @@ getObject bucket object = snd <$> getObject' bucket object [] []
 
 -- | Get an object's metadata from the object store.
 statObject :: Bucket -> Object -> Minio ObjectInfo
-statObject bucket object = headObject bucket object
+statObject = headObject
 
 -- | Creates a new bucket in the object store. The Region can be
 -- optionally specified. If not specified, it will use the region

src/Network/Minio/API.hs

@@ -108,7 +108,7 @@ buildRequest ri = do
 
   regionHost <- case region of
     Nothing ->  return $ connectHost ci
-    Just r -> if "amazonaws.com" `T.isSuffixOf` (connectHost ci)
+    Just r -> if "amazonaws.com" `T.isSuffixOf` connectHost ci
               then maybe
                    (throwM $ MErrVRegionNotSupported r)
                    return
@@ -118,7 +118,7 @@ buildRequest ri = do
 
   sha256Hash <- getPayloadSHA256Hash (riPayload ri)
   let newRi = ri { riPayloadHash = sha256Hash
-                 , riHeaders = sha256Header sha256Hash : (riHeaders ri)
+                 , riHeaders = sha256Header sha256Hash : riHeaders ri
                  , riRegion = region
                  }
       newCi = ci { connectHost = regionHost }

src/Network/Minio/Data.hs

@@ -248,12 +248,12 @@ instance Default CopyPartSource where
 
 cpsToHeaders :: CopyPartSource -> [HT.Header]
 cpsToHeaders cps = ("x-amz-copy-source", encodeUtf8 $ cpSource cps) :
-                   (rangeHdr ++ (zip names values))
+                   rangeHdr ++ zip names values
   where
     names = ["x-amz-copy-source-if-match", "x-amz-copy-source-if-none-match",
              "x-amz-copy-source-if-unmodified-since",
              "x-amz-copy-source-if-modified-since"]
-    values = concatMap (maybeToList . fmap encodeUtf8 . (cps &))
+    values = mapMaybe (fmap encodeUtf8 . (cps &))
              [cpSourceIfMatch, cpSourceIfNoneMatch,
               fmap formatRFC1123 . cpSourceIfUnmodifiedSince,
               fmap formatRFC1123 . cpSourceIfModifiedSince]
@@ -261,8 +261,7 @@ cpsToHeaders cps = ("x-amz-copy-source", encodeUtf8 $ cpSource cps) :
              . HT.renderByteRanges
              . (:[])
              . uncurry HT.ByteRangeFromTo
-           <$> (map (both fromIntegral) $
+           <$> map (both fromIntegral) (maybeToList $ cpSourceRange cps)
-                maybeToList $ cpSourceRange cps)
 
 -- | Extract the source bucket and source object name. TODO: validate
 -- the bucket and object name extracted.
@@ -299,7 +298,7 @@ instance Default RequestInfo where
   def = RequestInfo HT.methodGet def def def def def "" def True
 
 getPathFromRI :: RequestInfo -> ByteString
-getPathFromRI ri = B.concat $ parts
+getPathFromRI ri = B.concat parts
   where
     objPart = maybe [] (\o -> ["/", encodeUtf8 o]) $ riObject ri
     parts = maybe ["/"] (\b -> "/" : encodeUtf8 b : objPart) $ riBucket ri
@@ -347,7 +346,7 @@ runMinio :: ConnectInfo -> Minio a -> ResourceT IO (Either MinioErr a)
 runMinio ci m = do
   conn <- liftIO $ connect ci
   flip evalStateT Map.empty . flip runReaderT conn . unMinio $
-    (m >>= (return . Right)) `MC.catches`
+    fmap Right m `MC.catches`
     [ MC.Handler handlerServiceErr
     , MC.Handler handlerHE
     , MC.Handler handlerFE

src/Network/Minio/Data/ByteString.hs

@@ -25,7 +25,7 @@ import qualified Data.ByteString as B
 import qualified Data.ByteString.Builder as BB
 import qualified Data.ByteString.Char8 as BC8
 import qualified Data.ByteString.Lazy as LB
-import           Data.Char (isSpace, toUpper)
+import           Data.Char (isSpace, toUpper, isAsciiUpper, isAsciiLower, isDigit)
 import qualified Data.Text as T
 import           Numeric (showHex)
 
@@ -40,7 +40,7 @@ class UriEncodable s where
 instance UriEncodable [Char] where
   uriEncode encodeSlash payload =
     LB.toStrict $ BB.toLazyByteString $ mconcat $
-    map (flip uriEncodeChar encodeSlash) payload
+    map (`uriEncodeChar` encodeSlash) payload
 
 instance UriEncodable ByteString where
   -- assumes that uriEncode is passed ASCII encoded strings.
@@ -58,9 +58,9 @@ uriEncodeChar :: Char -> Bool -> BB.Builder
 uriEncodeChar '/' True = BB.byteString "%2F"
 uriEncodeChar '/' False = BB.char7 '/'
 uriEncodeChar ch _
-  | (ch >= 'A' && ch <= 'Z')
+  | isAsciiUpper ch
-    || (ch >= 'a' && ch <= 'z')
+    || isAsciiLower ch
-    || (ch >= '0' && ch <= '9')
+    || isDigit ch
     || (ch == '_')
     || (ch == '-')
     || (ch == '.')

src/Network/Minio/ListOps.hs

@@ -55,10 +55,9 @@ listIncompleteUploads bucket prefix recurse = loop Nothing Nothing
       res <- lift $ listIncompleteUploads' bucket prefix delimiter
              nextKeyMarker nextUploadIdMarker
 
-      aggrSizes <- lift $ forM (lurUploads res) $ \((uKey, uId, _)) -> do
+      aggrSizes <- lift $ forM (lurUploads res) $ \(uKey, uId, _) -> do
             partInfos <- listIncompleteParts bucket uKey uId C.$$ CC.sinkList
-            return $ foldl (\sizeSofar p -> opiSize p + sizeSofar) 0
+            return $ foldl (\sizeSofar p -> opiSize p + sizeSofar) 0 partInfos
-              $ partInfos
 
       CL.sourceList $
         map (\((uKey, uId, uInitTime), size) ->

src/Network/Minio/PutObject.hs

@@ -124,7 +124,7 @@ checkUploadNeeded :: Payload -> PartNumber
 checkUploadNeeded payload n pmap = do
   (md5hash, pSize) <- case payload of
     PayloadBS bs -> return (hashMD5 bs, fromIntegral $ B.length bs)
-    PayloadH h off size -> liftM (, size) $
+    PayloadH h off size -> fmap (, size) $
       hashMD5FromSource $ sourceHandleRange h (Just $ fromIntegral off)
       (Just $ fromIntegral size)
   case Map.lookup n pmap of
@@ -266,7 +266,7 @@ multiPartCopyObject b o cps srcSize = do
   copiedParts <- limitedMapConcurrently 10
                  (\(pn, cps') -> do
                      (etag, _) <- copyObjectPart b o cps' uid pn []
-                     return $ (pn, etag)
+                     return (pn, etag)
                  )
                  partSources
 

src/Network/Minio/S3API.hs

@@ -97,7 +97,7 @@ getObject' :: Bucket -> Object -> HT.Query -> [HT.Header]
            -> Minio ([HT.Header], C.ResumableSource Minio ByteString)
 getObject' bucket object queryParams headers = do
   resp <- mkStreamRequest reqInfo
-  return $ (NC.responseHeaders resp, NC.responseBody resp)
+  return (NC.responseHeaders resp, NC.responseBody resp)
   where
     reqInfo = def { riBucket = Just bucket
                   , riObject = Just object
@@ -107,8 +107,8 @@ getObject' bucket object queryParams headers = do
 
 -- | Creates a bucket via a PUT bucket call.
 putBucket :: Bucket -> Region -> Minio ()
-putBucket bucket location = do
+putBucket bucket location = void $
-  void $ executeRequest $
+  executeRequest $
     def { riMethod = HT.methodPut
         , riBucket = Just bucket
         , riPayload = PayloadBS $ mkCreateBucketConfig location
@@ -163,16 +163,16 @@ listObjects' bucket prefix nextToken delimiter = do
 
 -- | DELETE a bucket from the service.
 deleteBucket :: Bucket -> Minio ()
-deleteBucket bucket = do
+deleteBucket bucket = void $
-  void $ executeRequest $
+  executeRequest $
     def { riMethod = HT.methodDelete
         , riBucket = Just bucket
         }
 
 -- | DELETE an object from the service.
 deleteObject :: Bucket -> Object -> Minio ()
-deleteObject bucket object = do
+deleteObject bucket object = void $
-  void $ executeRequest $
+  executeRequest $
     def { riMethod = HT.methodDelete
         , riBucket = Just bucket
         , riObject = Just object
@@ -267,8 +267,8 @@ completeMultipartUpload bucket object uploadId partTuple = do
 
 -- | Abort a multipart upload.
 abortMultipartUpload :: Bucket -> Object -> UploadId -> Minio ()
-abortMultipartUpload bucket object uploadId = do
+abortMultipartUpload bucket object uploadId = void $
-  void $ executeRequest $ def { riMethod = HT.methodDelete
+  executeRequest $ def { riMethod = HT.methodDelete
                               , riBucket = Just bucket
                               , riObject = Just object
                               , riQueryParams = mkOptionalParams params
@@ -355,4 +355,4 @@ headBucket bucket = headBucketEx `catches`
       resp <- executeRequest $ def { riMethod = HT.methodHead
                                    , riBucket = Just bucket
                                    }
-      return $ (NC.responseStatus resp) == HT.ok200
+      return $ NC.responseStatus resp == HT.ok200

src/Network/Minio/Sign/V4.hs

@@ -98,10 +98,10 @@ signV4AtTime ts ci ri =
     outHeaders = authHeader : headersWithDate
     timeBS = awsTimeFormatBS ts
     dateHeader = (mk "X-Amz-Date", timeBS)
-    hostHeader = (mk "host", encodeUtf8 $ format "{}:{}" $
+    hostHeader = (mk "host", encodeUtf8 $ format "{}:{}"
                    [connectHost ci, show $ connectPort ci])
 
-    headersWithDate = dateHeader : hostHeader : (riHeaders ri)
+    headersWithDate = dateHeader : hostHeader : riHeaders ri
 
     authHeader = (mk "Authorization", authHeaderValue)
 
@@ -126,20 +126,20 @@ signV4AtTime ts ci ri =
                . hmacSHA256RawBS "s3"
                . hmacSHA256RawBS (encodeUtf8 region)
                . hmacSHA256RawBS (awsDateFormatBS ts)
-               $ (B.concat ["AWS4", encodeUtf8 $ connectSecretKey ci])
+               $ B.concat ["AWS4", encodeUtf8 $ connectSecretKey ci]
 
-    stringToSign  = B.intercalate "\n" $
+    stringToSign  = B.intercalate "\n"
-      ["AWS4-HMAC-SHA256",
+      [ "AWS4-HMAC-SHA256"
-       timeBS,
+      , timeBS
-       scope,
+      , scope
-       hashSHA256 $ canonicalRequest
+      , hashSHA256 canonicalRequest
       ]
 
     canonicalRequest = getCanonicalRequest ri headersToSign
 
 
 getScope :: UTCTime -> Region -> ByteString
-getScope ts region = B.intercalate "/" $ [
+getScope ts region = B.intercalate "/" [
   pack $ Time.formatTime Time.defaultTimeLocale "%Y%m%d" ts,
   encodeUtf8 region, "s3", "aws4_request"
   ]
@@ -148,11 +148,10 @@ getHeadersToSign :: [Header] -> [(ByteString, ByteString)]
 getHeadersToSign h =
   sort $
   filter (flip Set.notMember ignoredHeaders . fst) $
-  map (\(x, y) -> (CI.foldedCase x, stripBS y)) $
+  map (\(x, y) -> (CI.foldedCase x, stripBS y)) h
-  h
 
 getCanonicalRequest :: RequestInfo -> [(ByteString, ByteString)] -> ByteString
-getCanonicalRequest ri headersForSign = B.intercalate "\n" $ [
+getCanonicalRequest ri headersForSign = B.intercalate "\n" [
   riMethod ri,
   uriEncode False path,
   canonicalQueryString,
@@ -170,7 +169,6 @@ getCanonicalRequest ri headersForSign = B.intercalate "\n" $ [
       riQueryParams ri
 
     canonicalHeaders = B.concat $
-      map (\(x, y) -> B.concat [x, ":", y, "\n"]) $
+      map (\(x, y) -> B.concat [x, ":", y, "\n"]) headersForSign
-      headersForSign
 
     signedHeaders = B.intercalate ";" $ map fst headersForSign

src/Network/Minio/Utils.hs

@@ -117,7 +117,7 @@ httpLbs :: (R.MonadThrow m, MonadIO m)
         => NC.Request -> NC.Manager
         -> m (NC.Response LByteString)
 httpLbs req mgr = do
-  respE <- liftIO $ tryHttpEx $ (NC.httpLbs req mgr)
+  respE <- liftIO $ tryHttpEx $ NC.httpLbs req mgr
   resp <- either throwM return respE
   unless (isSuccessStatus $ NC.responseStatus resp) $
     case contentTypeMay resp of
@@ -126,11 +126,11 @@ httpLbs req mgr = do
         throwM sErr
 
       _ -> throwM $ NC.HttpExceptionRequest req $
-        NC.StatusCodeException (const () <$> resp) (show resp)
+        NC.StatusCodeException (void resp) (show resp)
 
   return resp
   where
-    tryHttpEx :: (IO (NC.Response LByteString))
+    tryHttpEx :: IO (NC.Response LByteString)
               -> IO (Either NC.HttpException (NC.Response LByteString))
     tryHttpEx = try
     contentTypeMay resp = lookupHeader Hdr.hContentType $
@@ -146,18 +146,18 @@ http req mgr = do
     case contentTypeMay resp of
       Just "application/xml" -> do
         respBody <- NC.responseBody resp C.$$+- CB.sinkLbs
-        sErr <- parseErrResponse $ respBody
+        sErr <- parseErrResponse respBody
         throwM sErr
 
       _ -> do
         content <- LB.toStrict . NC.responseBody <$> NC.lbsResponse resp
         throwM $ NC.HttpExceptionRequest req $
-           NC.StatusCodeException (const () <$> resp) $ content
+           NC.StatusCodeException (void resp) content
 
 
   return resp
   where
-    tryHttpEx :: (R.MonadResourceBase m) => (m a)
+    tryHttpEx :: (R.MonadResourceBase m) => m a
               -> m (Either NC.HttpException a)
     tryHttpEx = ExL.try
     contentTypeMay resp = lookupHeader Hdr.hContentType $ NC.responseHeaders resp
@@ -189,7 +189,7 @@ mkQuery k mv = (k,) <$> mv
 -- helper function to build query parameters that are optional.
 -- don't use it with mandatory query params with empty value.
 mkOptionalParams :: [(Text, Maybe Text)] -> HT.Query
-mkOptionalParams params = HT.toQuery $ (uncurry  mkQuery) <$> params
+mkOptionalParams params = HT.toQuery $ uncurry  mkQuery <$> params
 
 chunkBSConduit :: (Monad m, Integral a)
                => [a] -> C.Conduit ByteString m ByteString
@@ -199,9 +199,7 @@ chunkBSConduit s = loop 0 [] s
     loop n readChunks (size:sizes) = do
       bsMay <- C.await
       case bsMay of
-        Nothing -> if n > 0
+        Nothing -> when (n > 0) $ C.yield $ B.concat readChunks
-                   then C.yield $ B.concat readChunks
-                   else return ()
         Just bs -> if n + fromIntegral (B.length bs) >= size
                    then do let (a, b) = B.splitAt (fromIntegral $ size - n) bs
                                chunkBS = B.concat $ readChunks ++ [a]

src/Network/Minio/XmlParser.hs

@@ -76,7 +76,7 @@ parseListBuckets xmldata = do
     timeStrings = r $// s3Elem "Bucket" &// s3Elem "CreationDate" &/ content
 
   times <- mapM parseS3XMLTime timeStrings
-  return $ map (\(n, t) -> BucketInfo n t) $ zip names times
+  return $ zipWith BucketInfo names times
 
 -- | Parse the response XML of a location request.
 parseLocation :: (MonadThrow m) => LByteString -> m Region
@@ -107,7 +107,7 @@ parseCopyObjectResponse xmldata = do
     mtimeStr = T.concat $ r $// s3Elem "LastModified" &/ content
 
   mtime <- parseS3XMLTime mtimeStr
-  return $ (T.concat $ r $// s3Elem "ETag" &/ content, mtime)
+  return (T.concat $ r $// s3Elem "ETag" &/ content, mtime)
 
 -- | Parse the response XML of a list objects call.
 parseListObjectsResponse :: (MonadThrow m)