Add FromField Integer

test/Database/PostgreSQL/Opium/FromFieldSpec.hs

@@ -18,6 +18,12 @@ newtype AnInt = AnInt
 
 instance FromRow AnInt where
 
+newtype AnInteger = AnInteger
+  { integer :: Integer
+  } deriving (Eq, Generic, Show)
+
+instance FromRow AnInteger where
+
 newtype AText = AText
   { text :: Text
   } deriving (Eq, Generic, Show)
@@ -72,7 +78,17 @@ spec = do
       shouldFetch conn "SELECT 42::INTEGER AS int" [AnInt 42]
 
     it "Decodes bigint" $ \conn -> do
-      shouldFetch conn "SELECT 42::BIGINT AS int" [AnInt 42]
+      shouldFetch conn "SELECT pow(2, 48)::BIGINT AS int" [AnInt $ (2 :: Int) ^ (48 :: Int)]
+
+  describe "FromField Integer" $ do
+    it "Decodes smallint" $ \conn -> do
+      shouldFetch conn "SELECT 42::SMALLINT AS integer" [AnInteger 42]
+
+    it "Decodes integer" $ \conn -> do
+      shouldFetch conn "SELECT pow(2, 20)::INTEGER AS integer" [AnInteger $ (2 :: Integer) ^ (20 :: Integer)]
+
+    it "Decodes bigint" $ \conn -> do
+      shouldFetch conn "SELECT pow(2, 48)::BIGINT AS integer" [AnInteger $ (2 :: Integer) ^ (48 :: Integer)]
 
   describe "FromField Text" $ do
     it "Decodes text" $ \conn -> do