Resolve two todo's in commit/deposit

Signed-off-by: Sasha Bogicevic <[email protected]>

Author: v0d1ch

hydra-tx/src/Hydra/Tx/Commit.hs

@@ -67,7 +67,7 @@ commitTx networkId scriptRegistry headId party commitBlueprintTx (initialInput,
       & spendFromInitial
       & bodyTxL . outputsTxBodyL
         .~ ( StrictSeq.singleton (toLedgerTxOut commitOutput)
-              <> StrictSeq.singleton (toLedgerTxOut leftoverOutput)
+              <> leftoverOutput
            )
       & bodyTxL . mintTxBodyL .~ mempty
       & addMetadata (mkHydraHeadV1TxName "CommitTx") blueprintTx
@@ -149,11 +149,15 @@ commitTx networkId scriptRegistry headId party commitBlueprintTx (initialInput,
 
   commitOutput =
     TxOut commitAddress commitValue commitDatum ReferenceScriptNone
-  -- TODO: don't use head here
-  leftoverAddress = List.head $ txOutAddress <$> UTxO.txOutputs leftoverUTxO
 
   leftoverOutput =
-    TxOut leftoverAddress (UTxO.totalValue leftoverUTxO) TxOutDatumNone ReferenceScriptNone
+    if UTxO.null leftoverUTxO
+      then StrictSeq.empty
+      else
+        let leftoverAddress = List.head $ txOutAddress <$> UTxO.txOutputs leftoverUTxO
+         in StrictSeq.singleton $
+              toLedgerTxOut $
+                TxOut leftoverAddress (UTxO.totalValue leftoverUTxO) TxOutDatumNone ReferenceScriptNone
 
   commitAddress =
     mkScriptAddress networkId commitValidatorScript
@@ -178,10 +182,6 @@ updateTxOutValue :: TxOut ctx -> Coin -> TxOut ctx
 updateTxOutValue (TxOut addr _ datum refScript) newValue =
   TxOut addr (fromLedgerValue $ mkAdaValue ShelleyBasedEraConway newValue) datum refScript
 
--- | Generates a new TxIn by appending an index to avoid collisions
-newTxIn :: TxIn -> Word -> TxIn
-newTxIn (TxIn txId (TxIx txIx)) suffix = TxIn txId (TxIx $ txIx + suffix)
-
 -- | Caps a UTxO set to a specified target amount of Lovelace, splitting outputs if necessary.
 --
 -- Given a 'UTxO' set and a target 'Coin' value (in Lovelace), this function selects unspent transaction outputs

hydra-tx/src/Hydra/Tx/Deposit.hs

@@ -40,9 +40,7 @@ depositTx networkId headId commitBlueprintTx upperSlot deadline amount =
       & addDepositInputs
       & bodyTxL . outputsTxBodyL
         .~ ( StrictSeq.singleton (toLedgerTxOut $ mkDepositOutput networkId headId utxoToDeposit deadline)
-              <> if txOutValue leftoverOutput == mempty
-                then mempty
-                else StrictSeq.singleton (toLedgerTxOut leftoverOutput)
+              <> leftoverOutput
            )
       & bodyTxL . vldtTxBodyL .~ ValidityInterval{invalidBefore = SNothing, invalidHereafter = SJust upperSlot}
       & addMetadata (mkHydraHeadV1TxName "DepositTx") blueprintTx
@@ -55,11 +53,14 @@ depositTx networkId headId commitBlueprintTx upperSlot deadline amount =
 
   (utxoToDeposit, leftoverUTxO) = maybe (depositUTxO, mempty) (capUTxO depositUTxO) amount
 
-  -- TODO: don't use head here
-  leftoverAddress = List.head $ txOutAddress <$> UTxO.txOutputs leftoverUTxO
-
   leftoverOutput =
-    TxOut leftoverAddress (UTxO.totalValue leftoverUTxO) TxOutDatumNone ReferenceScriptNone
+    if UTxO.null leftoverUTxO
+      then StrictSeq.empty
+      else
+        let leftoverAddress = List.head $ txOutAddress <$> UTxO.txOutputs leftoverUTxO
+         in StrictSeq.singleton $
+              toLedgerTxOut $
+                TxOut leftoverAddress (UTxO.totalValue leftoverUTxO) TxOutDatumNone ReferenceScriptNone
 
   depositInputsList = toList (UTxO.inputSet utxoToDeposit)