Document and re-order arguments of 'decrement'

cardano-scaling · Jul 15, 2024 · 09e94c1 · 09e94c1
1 parent aa928f5
commit 09e94c1
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Showing 4 changed files with 13 additions and 11 deletions.
diff --git a/hydra-node/src/Hydra/Chain/Direct/Handlers.hs b/hydra-node/src/Hydra/Chain/Direct/Handlers.hs
@@ -370,7 +370,7 @@ prepareTxToPost timeHandle wallet ctx spendableUTxO tx =
         Left _ -> throwIO (FailedToConstructCollectTx @Tx)
         Right collectTx -> pure collectTx
     DecrementTx{headId, headParameters, snapshot, signatures} ->
-      case decrement ctx headId headParameters spendableUTxO snapshot signatures of
+      case decrement ctx spendableUTxO headId headParameters snapshot signatures of
         Left _ -> throwIO (FailedToConstructDecrementTx @Tx)
         Right decrementTx' -> pure decrementTx'
     CloseTx{headId, headParameters, confirmedSnapshot, version, closeUTxOToDecommit} -> do

diff --git a/hydra-node/src/Hydra/Chain/Direct/State.hs b/hydra-node/src/Hydra/Chain/Direct/State.hs
@@ -476,17 +476,19 @@ data DecrementTxError
   | SnapshotDecrementUTxOIsNull
   deriving stock (Show)
 
+-- | Construct a decrement transaction spending the head output in given 'UTxO',
+-- and producing outputs for all pending 'utxoToDecommit' of given 'Snapshot'.
 decrement ::
   ChainContext ->
-  HeadId ->
-  HeadParameters ->
   -- | Spendable UTxO containing head, initial and commit outputs
   UTxO ->
+  HeadId ->
+  HeadParameters ->
   -- | Confirmed Snapshot
   Snapshot Tx ->
   MultiSignature (Snapshot Tx) ->
   Either DecrementTxError Tx
-decrement ctx headId headParameters spendableUTxO snapshot signatures = do
+decrement ctx spendableUTxO headId headParameters snapshot signatures = do
   pid <- headIdToPolicyId headId ?> InvalidHeadIdInDecrement{headId}
   let utxoOfThisHead' = utxoOfThisHead pid spendableUTxO
   headUTxO <- UTxO.find (isScriptTxOut headScript) utxoOfThisHead' ?> CannotFindHeadOutputInDecrement
@@ -1044,7 +1046,7 @@ genDecrementTx numParties = do
     ( cctx
     , maybe mempty toList (utxoToDecommit snapshot)
     , stOpen
-    , unsafeDecrement cctx headId (ctxHeadParameters ctx) openUTxO snapshot signatures
+    , unsafeDecrement cctx openUTxO headId (ctxHeadParameters ctx) snapshot signatures
     )
 
 splitUTxO :: UTxO -> (UTxO, UTxO)
@@ -1180,15 +1182,15 @@ unsafeAbort ctx seedTxIn spendableUTxO committedUTxO =
 unsafeDecrement ::
   HasCallStack =>
   ChainContext ->
-  HeadId ->
-  HeadParameters ->
   -- | Spendable 'UTxO'
   UTxO ->
+  HeadId ->
+  HeadParameters ->
   Snapshot Tx ->
   MultiSignature (Snapshot Tx) ->
   Tx
-unsafeDecrement ctx headId parameters spendableUTxO snapshot signatures =
-  either (error . show) id $ decrement ctx headId parameters spendableUTxO snapshot signatures
+unsafeDecrement ctx spendableUTxO headId parameters snapshot signatures =
+  either (error . show) id $ decrement ctx spendableUTxO headId parameters snapshot signatures
 
 unsafeClose ::
   HasCallStack =>

diff --git a/hydra-node/test/Hydra/Chain/Direct/TxSpec.hs b/hydra-node/test/Hydra/Chain/Direct/TxSpec.hs
@@ -424,7 +424,7 @@ produceDecrement ::
   ([Bool], UTxO, Snapshot Tx, MultiSignature (Snapshot Tx)) ->
   ([Bool], UTxO, Snapshot Tx, MultiSignature (Snapshot Tx))
 produceDecrement ctx scriptRegistry headId parameters (p, spendableUTxO, snapshot, signatures) = do
-  case decrement ctx headId parameters spendableUTxO snapshot signatures of
+  case decrement ctx spendableUTxO headId parameters snapshot signatures of
     Left _ -> (p <> [False], spendableUTxO, snapshot, signatures)
     Right tx -> do
       case utxoToDecommit snapshot of

diff --git a/hydra-node/test/Hydra/Chain/Direct/TxTraceSpec.hs b/hydra-node/test/Hydra/Chain/Direct/TxTraceSpec.hs
@@ -740,9 +740,9 @@ newDecrementTx actor (snapshot, signatures) = do
   pure $
     decrement
       (actorChainContext actor)
+      spendableUTxO
       (mkHeadId Fixture.testPolicyId)
       Fixture.testHeadParameters
-      spendableUTxO
       snapshot
       signatures