Add a healthyCommitTx and validate it

Factored out 'mkInitialOutput' to be able to use it in the commit unit tests.

hydra-node/hydra-node.cabal

@@ -230,6 +230,7 @@ test-suite tests
     Hydra.BehaviorSpec
     Hydra.Chain.Direct.Contract.Close
     Hydra.Chain.Direct.Contract.CollectCom
+    Hydra.Chain.Direct.Contract.Commit
     Hydra.Chain.Direct.Contract.FanOut
     Hydra.Chain.Direct.Contract.Mutation
     Hydra.Chain.Direct.ContractSpec

hydra-node/src/Hydra/Chain/Direct/Tx.hs

@@ -132,7 +132,7 @@ initTx networkId cardanoKeys HeadParameters{contestationPeriod, parties} txIn =
     Api.unsafeBuildTransaction $
       Api.emptyTxBody
         & Api.addVkInputs [Api.fromLedgerTxIn txIn]
-        & Api.addOutputs (headOutput : map mkInitialOutput cardanoKeys)
+        & Api.addOutputs (headOutput : map (mkInitialOutput networkId) cardanoKeys)
  where
   headOutput =
     Api.TxOut headAddress headValue headDatum
@@ -148,15 +148,17 @@ initTx networkId cardanoKeys HeadParameters{contestationPeriod, parties} txIn =
         (contestationPeriodFromDiffTime contestationPeriod)
         (map (partyFromVerKey . vkey) parties)
 
-  mkInitialOutput (Api.toPlutusKeyHash . Api.verificationKeyHash -> vkh) =
-    Api.TxOut initialAddress initialValue (mkInitialDatum vkh)
-  initialScript =
-    Api.fromPlutusScript Initial.validatorScript
+mkInitialOutput :: NetworkId -> VerificationKey PaymentKey -> Api.TxOut Api.CtxTx Api.Era
+mkInitialOutput networkId (Api.toPlutusKeyHash . Api.verificationKeyHash -> vkh) =
+  Api.TxOut initialAddress initialValue (mkInitialDatum vkh)
+ where
   -- FIXME: should really be the minted PTs plus some ADA to make the ledger happy
   initialValue =
     Api.lovelaceToTxOutValue $ Api.Lovelace 2_000_000
   initialAddress =
     Api.mkScriptAddress @Api.PlutusScriptV1 networkId initialScript
+  initialScript =
+    Api.fromPlutusScript Initial.validatorScript
   mkInitialDatum =
     Api.mkTxOutDatum . Initial.datum
 

hydra-node/test/Hydra/Chain/Direct/Contract/Commit.hs

@@ -0,0 +1,52 @@
+-- | Mutation-based script validator tests for the commit transaction where a
+-- 'healthyCommitTx' gets mutated by an arbitrary 'genCommitMutation'
+module Hydra.Chain.Direct.Contract.Commit where
+
+import Hydra.Prelude
+
+import qualified Hydra.Chain.Direct.Fixture as Fixture
+import Hydra.Chain.Direct.Tx (commitTx, mkInitialOutput)
+import Hydra.Ledger.Cardano (CardanoTx, CtxUTxO, Era, PaymentKey, TxIn, TxOut, Utxo, VerificationKey, adaOnly, fromLedgerTx, genOutput, singletonUtxo, toCtxUTxOTxOut, toLedgerTxIn)
+import Hydra.Party (Party)
+
+-- Arbitrary VerificationKey instance
+import Hydra.Chain.Direct.TxSpec ()
+
+--
+-- CommitTx
+--
+
+healthyCommitTx :: (CardanoTx, Utxo)
+healthyCommitTx =
+  ( fromLedgerTx tx
+  , lookupUtxo
+  )
+ where
+  lookupUtxo = singletonUtxo (initialInput, toCtxUTxOTxOut initialOutput)
+
+  tx =
+    commitTx
+      Fixture.testNetworkId
+      healthyCommitParty
+      healthyCommittedUtxo
+      (toLedgerTxIn initialInput, initialPubKeyHash)
+
+  initialInput = generateWith arbitrary 42
+
+  initialOutput = mkInitialOutput Fixture.testNetworkId healthyCommitVerificationKey
+
+  initialPubKeyHash = generateWith arbitrary 42
+
+  -- NOTE: An ada-only output which is currently addressed to some arbitrary
+  -- public key.
+  healthyCommittedUtxo :: Maybe (TxIn, TxOut CtxUTxO Era)
+  healthyCommittedUtxo = flip generateWith 42 $ do
+    txIn <- arbitrary
+    txOut <- adaOnly <$> (genOutput =<< arbitrary)
+    pure $ Just (txIn, txOut)
+
+  healthyCommitVerificationKey :: VerificationKey PaymentKey
+  healthyCommitVerificationKey = generateWith arbitrary 42
+
+  healthyCommitParty :: Party
+  healthyCommitParty = generateWith arbitrary 42

hydra-node/test/Hydra/Chain/Direct/ContractSpec.hs

@@ -15,6 +15,7 @@ import qualified Data.ByteString as BS
 import qualified Data.ByteString.Base16 as Base16
 import Hydra.Chain.Direct.Contract.Close (genCloseMutation, healthyCloseTx)
 import Hydra.Chain.Direct.Contract.CollectCom (genCollectComMutation, healthyCollectComTx)
+import Hydra.Chain.Direct.Contract.Commit (healthyCommitTx)
 import Hydra.Chain.Direct.Contract.FanOut (genFanoutMutation, healthyFanoutTx)
 import Hydra.Chain.Direct.Contract.Mutation (
   genListOfSigningKeys,
@@ -73,6 +74,9 @@ spec = parallel $ do
   describe "TxOut hashing" $ do
     modifyMaxSuccess (const 20) $
       prop "OffChain.hashTxOuts == OnChain.hashTxOuts" prop_consistentOnAndOffChainHashOfTxOuts
+  describe "Commit" $ do
+    prop "is healthy" $
+      propTransactionValidates healthyCommitTx
   describe "CollectCom" $ do
     prop "is healthy" $
       propTransactionValidates healthyCollectComTx