From e59a6010c932ea6bf2171ad14ba579adb5740a91 Mon Sep 17 00:00:00 2001
From: Javier Sagredo <javier.sagredo@iohk.io>
Date: Wed, 29 Jan 2025 11:22:17 +0100
Subject: [PATCH] Add CBOR instances for DefaultVote

---
 eras/conway/impl/CHANGELOG.md                 |  1 +
 .../src/Cardano/Ledger/Conway/Governance.hs   | 21 +++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/eras/conway/impl/CHANGELOG.md b/eras/conway/impl/CHANGELOG.md
index c486e983407..97dc83f10f6 100644
--- a/eras/conway/impl/CHANGELOG.md
+++ b/eras/conway/impl/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## 1.19.0.0
 
+* Added `ToCBOR` and `FromCBOR` instances for `DefaultVote`.
 * Made the fields of predicate failures and environments lazy
 * Add `MemPack` instance for `PlutusScript ConwayEra`
 * Deprecate `Conway` type synonym
diff --git a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs
index 605c804ba47..ef3069a507f 100644
--- a/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs
+++ b/eras/conway/impl/src/Cardano/Ledger/Conway/Governance.hs
@@ -202,6 +202,10 @@ import Cardano.Ledger.Binary.Coders (
   (!>),
   (<!),
  )
+import Cardano.Ledger.Binary.Plain (
+  decodeWord8,
+  encodeWord8,
+ )
 import Cardano.Ledger.CertState (
   CommitteeAuthorization (..),
   Obligations (..),
@@ -541,6 +545,23 @@ data DefaultVote
     DefaultNoConfidence
   deriving (Eq, Show)
 
+instance FromCBOR DefaultVote where
+  fromCBOR = do
+    tag <- decodeWord8
+    case tag of
+      0 -> pure DefaultNo
+      1 -> pure DefaultAbstain
+      2 -> pure DefaultNoConfidence
+      _ -> fail $ "Invalid DefaultVote tag " ++ show tag
+
+instance ToCBOR DefaultVote where
+  toCBOR DefaultNo = encodeWord8 0
+  toCBOR DefaultAbstain = encodeWord8 1
+  toCBOR DefaultNoConfidence = encodeWord8 2
+
+instance EncCBOR DefaultVote
+instance DecCBOR DefaultVote
+
 defaultStakePoolVote ::
   -- | Specify the key hash of the pool whose default vote should be returned.
   KeyHash 'StakePool ->