fix issue: createItem not serializing Nothings correctly

Author: jmartinez-sb

rollbar-client/rollbar-client.cabal

@@ -99,4 +99,5 @@ test-suite spec
     , text
     , unordered-containers
     , yaml
+    , bytestring
   default-language: Haskell2010

rollbar-client/src/Rollbar/Client/Item.hs

@@ -97,15 +97,15 @@ instance ToJSON Item where
     let dataFields =
           [ "environment" .= itemEnvironment
           , "body" .= itemBody
-          , "level" .= itemLevel
-          , "platform" .= itemPlatform
-          , "language" .= itemLanguage
-          , "framework" .= itemFramework
-          , "request" .= itemRequest
-          , "server" .= itemServer
           , "notifier" .= itemNotifier
           ] ++ catMaybes
-          [ ("custom" .=) <$> custom
+          [  ("level" .=) <$> itemLevel
+           , ("platform" .=) <$> itemPlatform
+           , ("language" .=) <$> itemLanguage
+           , ("framework" .=) <$> itemFramework
+           , ("request" .=) <$> itemRequest
+           , ("server" .=) <$> itemServer
+           , ("custom" .=) <$> custom
            , ("fingerprint" .=) <$> fingerprint
            , ("title" .=) <$> title
            , ("uuid" .=) <$> uuid

rollbar-client/test/Rollbar/ClientSpec.hs

@@ -11,10 +11,12 @@ import qualified Data.Aeson.KeyMap as KM
 
 import Control.Monad.Reader
 import Data.Aeson
-import Data.Text
+import Data.Text as T
 import Data.Yaml.Config
 import Rollbar.Client
 import Test.Hspec
+import Data.Text.Encoding
+import Data.ByteString as DB
 
 data Package = Package
   { packageName :: Text
@@ -143,3 +145,28 @@ spec = do
           reportDeploy deploy
 
         deployId `shouldSatisfy` (> 0)
+
+  describe "ToJSON Item" $ do
+    context "when serializing to JSON" $ do
+      let item = Item
+            { itemEnvironment = Environment "test"
+            , itemBody = Body { bodyPayload = PayloadMessage (Message "Test" mempty) }
+            , itemLevel = Just LevelInfo
+            , itemPlatform = Just "haskell"
+            , itemLanguage = Just "Haskell"
+            , itemFramework = Just "GHC"
+            , itemRequest = Nothing
+            , itemServer = Nothing
+            , custom = Just mempty
+            , title = Nothing
+            , uuid = Just "12345"
+            , fingerprint = Nothing
+            , itemNotifier = Notifier "rollbar-client" "1.1.0"
+            }
+          jsonItem = decodeUtf8 $ toStrict $ encode item
+
+      it "omits fields if they are Nothing values" $
+        T.unpack jsonItem `shouldNotContain` "\"server\""
+
+      it "includes fields if they are Just values" $ 
+        T.unpack jsonItem `shouldContain` "\"platform\":\"haskell\""