Fix the swagger output

See conversation here haskell-servant/servant-swagger#80

Author: Ben Ford

faucet/src/Cardano/Faucet.hs

@@ -39,7 +39,7 @@ withdraw wd = withSublogger (LoggerName "withdraw") $ do
             logError ("Error withdrawing " <> (wd ^. to show . packed)
                                            <> " error: "
                                            <> (err ^. to show . packed))
-            return $ WithdrawlError err
+            return $ WithdrawlError (show err ^. packed)
         Right wr -> do
             let txn = wrData wr
                 amount = unV1 $ txAmount txn

faucet/src/Cardano/Faucet/Types/API.hs

@@ -21,6 +21,7 @@ import           Control.Lens hiding ((.=))
 import           Data.Aeson (FromJSON (..), ToJSON (..), object, withObject, (.:), (.=))
 import Data.Monoid ((<>))
 import           Data.Text (Text)
+import qualified Data.Char as Char
 -- import           Data.Text (Text)
 import           Data.Typeable (Typeable)
 import           GHC.Generics (Generic)
@@ -60,30 +61,33 @@ instance ToSchema WithdrawlRequest where
 --------------------------------------------------------------------------------
 -- | The result of processing a 'WithdrawlRequest'
 data WithdrawlResult =
-    WithdrawlError ClientError   -- ^ Error with http client error
+    WithdrawlError Text   -- ^ Error with http client error
   | WithdrawlSuccess Transaction -- ^ Success with transaction details
   deriving (Show, Typeable, Generic)
 
 instance ToJSON WithdrawlResult where
     toJSON (WithdrawlSuccess txn) =
         object ["success" .= txn]
     toJSON (WithdrawlError err) =
-        object ["error" .= show err]
+        object ["error" .= err]
 
 wdDesc :: Text
 wdDesc = "An object with either a success field containing the transaction or "
       <> "an error field containing the ClientError from the wallet as a string"
 
 instance ToSchema WithdrawlResult where
-    declareNamedSchema _ = do
-        txnSchema <- declareSchemaRef (Proxy :: Proxy Transaction)
-        errSchema <- declareSchemaRef (Proxy :: Proxy String)
-        return $ NamedSchema (Just "WithdrawlResult") $ mempty
-          & type_ .~ SwaggerObject
-          & properties .~ (mempty
-               & at "success" ?~ txnSchema
-               & at "error" ?~ errSchema)
-          & description .~ (Just $ wdDesc)
+    declareNamedSchema = genericDeclareNamedSchema defaultSchemaOptions
+      { constructorTagModifier = map Char.toLower . drop (length ("Withdrawl" :: String)) }
+      & mapped.mapped.schema.description ?~ wdDesc
+    -- declareNamedSchema _ = do
+    --     txnSchema <- declareSchemaRef (Proxy :: Proxy Transaction)
+    --     errSchema <- declareSchemaRef (Proxy :: Proxy Char)
+    --     return $ NamedSchema (Just "WithdrawlResult") $ mempty
+    --       & type_ .~ SwaggerObject
+    --       & properties .~ (mempty
+    --            & at "success" ?~ txnSchema
+    --            & at "error" ?~ errSchema)
+    --       & description .~ (Just $ wdDesc)
 
 --------------------------------------------------------------------------------
 -- | A request to deposit ADA back into the wallet __not currently used__