Add number of decommit outputs to the Decrement redeemer

input-output-hk · May 7, 2024 · 203e782 · 203e782
1 parent 003b362
commit 203e782
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Showing 4 changed files with 23 additions and 14 deletions.
diff --git a/hydra-node/src/Hydra/Chain/Direct/Tx.hs b/hydra-node/src/Hydra/Chain/Direct/Tx.hs
@@ -444,7 +444,13 @@ decrementTx scriptRegistry vk headId headParameters (headInput, headOutput) snap
       & addOutputs (headOutput' : map toTxContext (maybe [] toList utxoToDecommit))
       & addExtraRequiredSigners [verificationKeyHash vk]
  where
-  headRedeemer = toScriptData $ Head.Decrement (toPlutusSignatures signatures)
+  headRedeemer =
+    toScriptData $
+      Head.Decrement
+        { signature = toPlutusSignatures signatures
+        , numberOfDecommitOutputs =
+            fromIntegral $ length $ maybe [] toList utxoToDecommit
+        }
   utxoHash = toBuiltin $ hashUTxO @Tx utxo
 
   HeadParameters{parties, contestationPeriod} = headParameters

diff --git a/hydra-node/test/Hydra/Chain/Direct/Contract/Decrement.hs b/hydra-node/test/Hydra/Chain/Direct/Contract/Decrement.hs
@@ -128,13 +128,14 @@ healthyUTxO = adaOnly <$> generateWith (genUTxOSized 3) 42
 
 healthyDatum :: Head.State
 healthyDatum =
-  Head.Open
-    { utxoHash = toBuiltin $ hashUTxO @Tx healthyUTxO
-    , parties = healthyOnChainParties
-    , contestationPeriod = toChain healthyContestationPeriod
-    , snapshotNumber = toInteger healthySnapshotNumber
-    , headId = toPlutusCurrencySymbol testPolicyId
-    }
+  let (_utxoToDecommit', utxo) = splitDecommitUTxO healthyUTxO
+   in Head.Open
+        { utxoHash = toBuiltin $ hashUTxO @Tx utxo
+        , parties = healthyOnChainParties
+        , contestationPeriod = toChain healthyContestationPeriod
+        , snapshotNumber = toInteger healthySnapshotNumber
+        , headId = toPlutusCurrencySymbol testPolicyId
+        }
 
 data DecrementMutation
   = -- | Ensures parties do not change between head input datum and head output
@@ -160,7 +161,7 @@ data DecrementMutation
   deriving stock (Generic, Show, Enum, Bounded)
 
 genDecrementMutation :: (Tx, UTxO) -> Gen SomeMutation
-genDecrementMutation (tx, _utxo) =
+genDecrementMutation (tx, utxo) =
   oneof
     [ SomeMutation (Just $ toErrorCode ChangedParameters) MutatePartiesInOutput <$> do
         mutatedParties <- arbitrary `suchThat` (/= healthyOnChainParties)
@@ -169,7 +170,7 @@ genDecrementMutation (tx, _utxo) =
         mutatedSnapshotNumber <- arbitrarySizedNatural `suchThat` (< healthySnapshotNumber)
         pure $ ChangeOutput 0 $ modifyInlineDatum (replaceSnapshotNumberInOpen $ toInteger mutatedSnapshotNumber) headTxOut
     , SomeMutation (Just $ toErrorCode SignatureVerificationFailed) SnapshotSignatureInvalid . ChangeHeadRedeemer <$> do
-        Head.Decrement . toPlutusSignatures <$> (arbitrary :: Gen (MultiSignature (Snapshot Tx)))
+        Head.Decrement . toPlutusSignatures <$> (arbitrary :: Gen (MultiSignature (Snapshot Tx))) <*> pure (fromIntegral $ length utxo - 1)
     , SomeMutation (Just $ toErrorCode SignerIsNotAParticipant) MutateRequiredSigner <$> do
         newSigner <- verificationKeyHash <$> genVerificationKey `suchThat` (/= somePartyCardanoVerificationKey)
         pure $ ChangeRequiredSigners [newSigner]

diff --git a/hydra-plutus/src/Hydra/Contract/Head.hs b/hydra-plutus/src/Hydra/Contract/Head.hs
@@ -73,8 +73,8 @@ headValidator oldState input ctx =
       checkCollectCom ctx (contestationPeriod, parties, headId)
     (Initial{parties, headId}, Abort) ->
       checkAbort ctx headId parties
-    (Open{parties, contestationPeriod, snapshotNumber, headId}, Decrement{signature}) ->
-      checkDecrement ctx parties snapshotNumber contestationPeriod headId signature
+    (Open{parties, contestationPeriod, snapshotNumber, headId}, Decrement{signature, numberOfDecommitOutputs}) ->
+      checkDecrement ctx parties snapshotNumber contestationPeriod headId signature numberOfDecommitOutputs
     (Open{parties, utxoHash = initialUtxoHash, contestationPeriod, headId}, Close{signature}) ->
       checkClose ctx parties initialUtxoHash signature contestationPeriod headId
     (Closed{parties, snapshotNumber = closedSnapshotNumber, contestationDeadline, contestationPeriod, headId, contesters}, Contest{signature}) ->
@@ -235,8 +235,9 @@ checkDecrement ::
   ContestationPeriod ->
   CurrencySymbol ->
   [Signature] ->
+  Integer ->
   Bool
-checkDecrement ctx@ScriptContext{scriptContextTxInfo = txInfo} prevParties prevSnapshotNumber prevCperiod prevHeadId signature =
+checkDecrement ctx@ScriptContext{scriptContextTxInfo = txInfo} prevParties prevSnapshotNumber prevCperiod prevHeadId signature numberOfDecommitOutputs =
   mustNotChangeParameters
     && checkSnapshot
     && checkSnapshotSignature
@@ -251,7 +252,7 @@ checkDecrement ctx@ScriptContext{scriptContextTxInfo = txInfo} prevParties prevS
 
   headInValue = maybe mempty (txOutValue . txInInfoResolved) $ findOwnInput ctx
 
-  decommitOutputs = tail (txInfoOutputs txInfo)
+  decommitOutputs = take numberOfDecommitOutputs (tail $ txInfoOutputs txInfo)
 
   -- NOTE: we always assume Head output is the first one so we pick all other
   -- outputs of a decommit tx to calculate the expected hash.

diff --git a/hydra-plutus/src/Hydra/Contract/HeadState.hs b/hydra-plutus/src/Hydra/Contract/HeadState.hs
@@ -55,6 +55,7 @@ data Input
   = CollectCom
   | Decrement
       { signature :: [Signature]
+      , numberOfDecommitOutputs :: Integer
       }
   | Close
       { signature :: [Signature]