From 3ab8034cc196892e117972544c831f620a252877 Mon Sep 17 00:00:00 2001
From: Sebastian Nagel <sebastian.nagel@ncoding.at>
Date: Wed, 4 Sep 2024 17:52:30 +0200
Subject: [PATCH] Use newtype derived Arbitrary where possible

---
 hydra-tx/src/Hydra/Tx/Party.hs    |  4 +---
 hydra-tx/src/Hydra/Tx/Snapshot.hs | 10 ++--------
 2 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/hydra-tx/src/Hydra/Tx/Party.hs b/hydra-tx/src/Hydra/Tx/Party.hs
index cc55b7f1b68..6884832d1e1 100644
--- a/hydra-tx/src/Hydra/Tx/Party.hs
+++ b/hydra-tx/src/Hydra/Tx/Party.hs
@@ -24,6 +24,7 @@ import Hydra.Tx.Crypto (AsType (AsHydraKey), HydraKey)
 newtype Party = Party {vkey :: VerificationKey HydraKey}
   deriving stock (Eq, Show, Generic)
   deriving anyclass (ToJSON, FromJSON)
+  deriving newtype (Arbitrary)
 
 instance ToJSONKey Party where
   toJSONKey = toJSONKeyText (serialiseToRawBytesHexText . vkey)
@@ -43,9 +44,6 @@ instance Ord Party where
   Party{vkey = a} <= Party{vkey = b} =
     verificationKeyHash a <= verificationKeyHash b
 
-instance Arbitrary Party where
-  arbitrary = Party <$> arbitrary
-
 instance FromCBOR Party where
   fromCBOR = Party <$> fromCBOR
 
diff --git a/hydra-tx/src/Hydra/Tx/Snapshot.hs b/hydra-tx/src/Hydra/Tx/Snapshot.hs
index 0335d92b6ee..30af5757954 100644
--- a/hydra-tx/src/Hydra/Tx/Snapshot.hs
+++ b/hydra-tx/src/Hydra/Tx/Snapshot.hs
@@ -23,29 +23,23 @@ import Test.QuickCheck.Instances.Natural ()
 newtype SnapshotNumber
   = UnsafeSnapshotNumber Natural
   deriving stock (Eq, Ord, Generic)
-  deriving newtype (Show, ToJSON, FromJSON, ToCBOR, FromCBOR, Real, Num, Enum, Integral)
+  deriving newtype (Show, ToJSON, FromJSON, ToCBOR, FromCBOR, Real, Num, Enum, Integral, Arbitrary)
 
 -- NOTE: On-chain scripts ensure snapshot number does not become negative.
 fromChainSnapshotNumber :: Onchain.SnapshotNumber -> SnapshotNumber
 fromChainSnapshotNumber =
   UnsafeSnapshotNumber . fromMaybe 0 . integerToNatural
 
-instance Arbitrary SnapshotNumber where
-  arbitrary = UnsafeSnapshotNumber <$> arbitrary
-
 newtype SnapshotVersion
   = UnsafeSnapshotVersion Natural
   deriving stock (Eq, Ord, Generic)
-  deriving newtype (Show, ToJSON, FromJSON, ToCBOR, FromCBOR, Real, Num, Enum, Integral)
+  deriving newtype (Show, ToJSON, FromJSON, ToCBOR, FromCBOR, Real, Num, Enum, Integral, Arbitrary)
 
 -- NOTE: On-chain scripts ensure snapshot version does not become negative.
 fromChainSnapshotVersion :: Onchain.SnapshotVersion -> SnapshotVersion
 fromChainSnapshotVersion =
   UnsafeSnapshotVersion . fromMaybe 0 . integerToNatural
 
-instance Arbitrary SnapshotVersion where
-  arbitrary = UnsafeSnapshotVersion <$> arbitrary
-
 -- * Snapshot
 
 data Snapshot tx = Snapshot