Combine value inserted into the OrderedMap

tests/Language/GraphQL/Execute/OrderedMapSpec.hs

@@ -3,15 +3,22 @@
    obtain one at https://mozilla.org/MPL/2.0/. -}
 
 {-# LANGUAGE OverloadedStrings #-}
+
 module Language.GraphQL.Execute.OrderedMapSpec
     ( spec
     ) where
 
 import Language.GraphQL.Execute.OrderedMap (OrderedMap)
-import Test.Hspec (Spec, describe, it, shouldSatisfy)
+import qualified Language.GraphQL.Execute.OrderedMap as OrderedMap
+import Test.Hspec (Spec, describe, it, shouldBe, shouldSatisfy)
 
 spec :: Spec
 spec =
-    describe "OrderedMap" $
+    describe "OrderedMap" $ do
         it "creates an empty map" $
-            (mempty :: OrderedMap Int) `shouldSatisfy` null
+            (mempty :: OrderedMap String) `shouldSatisfy` null
+
+        it "creates a singleton" $
+            let value :: String
+                value = "value"
+             in OrderedMap.size (OrderedMap.singleton "key" value) `shouldBe` 1