Add FromField Char

test/Database/PostgreSQL/Opium/FromFieldSpec.hs

@@ -30,6 +30,12 @@ newtype AString = AString
 
 instance FromRow AString where
 
+newtype AChar = AChar
+  { char :: Char
+  } deriving (Eq, Generic, Show)
+
+instance FromRow AChar where
+
 newtype AFloat = AFloat
   { float :: Float
   } deriving (Eq, Generic, Show)
@@ -90,6 +96,17 @@ spec = do
     it "Decodes character varying" $ \conn -> do
       shouldFetch conn "SELECT 'Hello, World!'::CHARACTER VARYING (20) AS string" [AString "Hello, World!"]
 
+  describe "FromField Char" $ do
+    it "Decodes text" $ \conn -> do
+      shouldFetch conn "SELECT 'X'::TEXT AS char" [AChar 'X']
+
+    it "Decodes character" $ \conn -> do
+      shouldFetch conn "SELECT 'XYZ'::CHARACTER(1) AS char" [AChar 'X']
+      shouldFetch conn "SELECT ''::CHARACTER(1) AS char" [AChar ' ']
+
+    it "Decodes character varying" $ \conn -> do
+      shouldFetch conn "SELECT 'X'::CHARACTER VARYING (20) AS char" [AChar 'X']
+
   describe "FromField Float" $ do
     it "Decodes real" $ \conn -> do
       shouldFetch conn "SELECT 4.2::real AS float" [AFloat 4.2]