Remove unused instances

Thanks weeder

Author: ch1bo

hydra-node/src/Hydra/Chain.hs

@@ -35,7 +35,6 @@ import Hydra.Tx (
 import Hydra.Tx.IsTx (ArbitraryIsTx)
 import Hydra.Tx.OnChainId (OnChainId)
 import Test.Cardano.Ledger.Core.Arbitrary ()
-import Test.QuickCheck.Arbitrary.ADT (ToADTArbitrary)
 import Test.QuickCheck.Instances.Semigroup ()
 import Test.QuickCheck.Instances.Time ()
 
@@ -162,13 +161,10 @@ data OnChainTx tx
 deriving stock instance IsTx tx => Eq (OnChainTx tx)
 deriving stock instance IsTx tx => Show (OnChainTx tx)
 deriving anyclass instance IsTx tx => ToJSON (OnChainTx tx)
-deriving anyclass instance IsTx tx => FromJSON (OnChainTx tx)
 
 instance ArbitraryIsTx tx => Arbitrary (OnChainTx tx) where
   arbitrary = genericArbitrary
 
-instance ArbitraryIsTx tx => ToADTArbitrary (OnChainTx tx)
-
 -- | Exceptions thrown by 'postTx'.
 data PostTxError tx
   = NoSeedInput

hydra-tx/testlib/Test/Hydra/Tx/Gen.hs

@@ -22,7 +22,7 @@ import Hydra.Contract.Head qualified as Head
 import Hydra.Plutus (commitValidatorScript, initialValidatorScript)
 import Hydra.Plutus.Orphans ()
 import Hydra.Tx (ScriptRegistry (..))
-import Hydra.Tx.Close (CloseObservation, OpenThreadOutput)
+import Hydra.Tx.Close (CloseObservation)
 import Hydra.Tx.Crypto (Hash (..))
 import Hydra.Tx.Observe (AbortObservation, CollectComObservation, CommitObservation, ContestObservation, DecrementObservation, DepositObservation, FanoutObservation, HeadObservation, IncrementObservation, InitObservation, RecoverObservation)
 import Hydra.Tx.Party (Party (..))
@@ -259,10 +259,6 @@ genScriptRegistry = do
           )
       }
 
-instance Arbitrary OpenThreadOutput where
-  arbitrary = genericArbitrary
-  shrink = genericShrink
-
 instance Arbitrary Tx where
   -- TODO: shrinker!
   arbitrary = fromLedgerTx <$> arbitrary