transaction submit: print transaction hash as JSON

cardano-cli/src/Cardano/CLI/EraBased/Run/Transaction.hs

@@ -1483,7 +1483,9 @@ runTransactionSubmitCmd
 
     res <- liftIO $ submitTxToNodeLocal localNodeConnInfo txInMode
     case res of
-      Net.Tx.SubmitSuccess -> liftIO $ Text.putStrLn "Transaction successfully submitted."
+      Net.Tx.SubmitSuccess -> do
+        liftIO $ Text.hPutStrLn IO.stderr "Transaction successfully submitted. Transaction hash is:"
+        liftIO $ LBS.putStrLn $ Aeson.encode $ TxSubmissionResult $ getTxId $ getTxBody tx
       Net.Tx.SubmitFail reason ->
         case reason of
           TxValidationErrorInCardanoMode err -> left . TxCmdTxSubmitError . Text.pack $ show err

cardano-cli/src/Cardano/CLI/Types/Common.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE GeneralisedNewtypeDeriving #-}
@@ -68,6 +69,7 @@ module Cardano.CLI.Types.Common
   , TxBuildOutputOptions (..)
   , TxByronWitnessCount (..)
   , TxFile
+  , TxSubmissionResult (..)
   , TxTreasuryDonation (..)
   , TxInCount (..)
   , TxMempoolQuery (..)
@@ -102,6 +104,7 @@ import           Data.String (IsString)
 import           Data.Text (Text)
 import qualified Data.Text as Text
 import           Data.Word (Word64)
+import           GHC.Generics (Generic)
 
 -- | Determines the direction in which the MIR certificate will transfer ADA.
 data TransferDirection
@@ -663,3 +666,12 @@ data PotentiallyCheckedAnchor anchorType anchor
   -- ^ Whether to check the hash or not (CheckHash for checking or TrustHash for not checking)
   }
   deriving (Eq, Show)
+
+-- | Type used for serialization when printing the hash of a transaction
+-- after having submitted it.
+newtype TxSubmissionResult = TxSubmissionResult {txhash :: TxId}
+  deriving (Show, Generic)
+
+instance FromJSON TxSubmissionResult
+
+instance ToJSON TxSubmissionResult