Replace ToJSON/FromJSON Tx with cbor encoding

hydra-node/src/Hydra/Ledger/Cardano.hs

@@ -15,6 +15,7 @@ import Hydra.Ledger.Cardano.Builder
 import Cardano.Api.UTxO (fromPairs, pairs)
 import Cardano.Api.UTxO qualified as UTxO
 import Cardano.Crypto.DSIGN qualified as CC
+import Cardano.Ledger.Api (Babbage)
 import Cardano.Ledger.Babbage.Tx qualified as Ledger
 import Cardano.Ledger.BaseTypes (StrictMaybe (..))
 import Cardano.Ledger.BaseTypes qualified as Ledger
@@ -28,6 +29,8 @@ import Cardano.Ledger.Shelley.UTxO qualified as Ledger
 import Codec.CBOR.Decoding qualified as CBOR
 import Codec.CBOR.Encoding qualified as CBOR
 import Control.Monad (foldM)
+import Data.Aeson (withObject, (.:))
+import Data.Aeson qualified as Aeson
 import Data.ByteString qualified as BS
 import Data.Default (def)
 import Data.Map.Strict qualified as Map
@@ -36,7 +39,7 @@ import Data.Text.Lazy.Builder (toLazyText)
 import Formatting.Buildable (build)
 import Hydra.Contract.Head qualified as Head
 import Hydra.Ledger (ChainSlot (..), IsTx (..), Ledger (..), ValidationError (..))
-import Hydra.Ledger.Cardano.Json ()
+import Hydra.Ledger.Cardano.Json (parseHexEncodedCborAnnotated)
 import PlutusLedgerApi.V2 (fromBuiltin)
 import Test.Cardano.Ledger.Babbage.Arbitrary ()
 import Test.QuickCheck (
@@ -50,6 +53,7 @@ import Test.QuickCheck (
   suchThat,
   vectorOf,
  )
+import qualified Data.ByteString.Base16 as Base16
 
 -- * Ledger
 
@@ -125,10 +129,21 @@ instance FromCBOR Tx where
         (pure . fromLedgerTx)
 
 instance ToJSON Tx where
-  toJSON = toJSON . toLedgerTx
+  toJSON tx = Aeson.String $ decodeUtf8 @Text $ Base16.encode $ serialiseToCBOR tx
 
 instance FromJSON Tx where
-  parseJSON = fmap fromLedgerTx . parseJSON
+  parseJSON value =
+    fromLedgerTx
+      <$> ( parseAsEnvelopedBase16CBOR value
+              <|> parseHexEncodedCborAnnotated @Babbage "Tx" value
+          )
+   where
+    parseAsEnvelopedBase16CBOR =
+      withObject "Tx" $ \o -> do
+        let TextEnvelopeType envelopeType = textEnvelopeType (proxyToAsType (Proxy @Tx))
+        str <- o .: "cborHex"
+        guard . (== envelopeType) =<< (o .: "type")
+        parseHexEncodedCborAnnotated @Babbage "Tx" (Aeson.String str)
 
 instance Arbitrary Tx where
   -- TODO: shrinker!