test(golden): add comprehensive golden tests for TxOut serialization

Implements golden tests to ensure backwards compatibility of JSON
serialization for types whose ToJSON/FromJSON instances were migrated
from IsShelleyBasedEra/IsCardanoEra constraints to Exp.IsEra constraints.
This ensures that the new constraint system maintains format compatibility.

- Add golden test infrastructure for TxOut types across Conway era
- Create test helpers for constructing consistent test addresses and values
- Implement tests for various TxOut configurations including simple outputs,
  datum hashes, inline datums, and reference scripts
- Add TxOutValue tests for both lovelace-only and multi-asset values
- Include AddressInEra and ReferenceScript golden tests
- Test UTxO serialization with multiple outputs
- Generate golden files with pretty-printed JSON for readability

These tests guard against regression in JSON format compatibility as
the codebase transitions to the new Exp.IsEra constraint system.

Author: newhoggy

cardano-api/cardano-api.cabal

@@ -437,6 +437,7 @@ test-suite cardano-api-golden
     buildable: False
   build-depends:
     aeson,
+    aeson-pretty,
     base64-bytestring,
     bech32 >=1.1.0,
     bytestring,
@@ -475,5 +476,6 @@ test-suite cardano-api-golden
     Test.Golden.Cardano.Api.Genesis
     Test.Golden.Cardano.Api.Ledger
     Test.Golden.Cardano.Api.Script
+    Test.Golden.Cardano.Api.TxOut
     Test.Golden.Cardano.Api.Value
     Test.Golden.ErrorsSpec

cardano-api/test/cardano-api-golden/GenGolden.hs

@@ -0,0 +1,257 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE NumericUnderscores #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+
+-- | Script to generate golden test files
+module GenGolden where
+
+import Cardano.Api
+import Cardano.Api.Ledger qualified as L
+
+import Control.Error.Util (hush)
+import Data.Aeson (encode)
+import Data.ByteString (ByteString)
+import Data.ByteString.Lazy qualified as BL
+import Data.ByteString.Lazy.Char8 qualified as BL8
+import Data.Maybe (fromJust)
+import GHC.Exts (IsList (..))
+import System.FilePath ((</>))
+
+goldenPath :: FilePath
+goldenPath = "test/cardano-api-golden/files/TxOut"
+
+main :: IO ()
+main = do
+  createDirectoryIfMissing True (goldenPath </> "conway")
+  createDirectoryIfMissing True (goldenPath </> "dijkstra")
+
+  -- Conway TxOut tests
+  writeGolden (goldenPath </> "conway" </> "txout-simple.json") txOutConwaySimple
+  writeGolden (goldenPath </> "conway" </> "txout-datumhash.json") txOutConwayDatumHash
+  writeGolden (goldenPath </> "conway" </> "txout-inlinedatum.json") txOutConwayInlineDatum
+  writeGolden (goldenPath </> "conway" </> "txout-referencescript.json") txOutConwayReferenceScript
+  writeGolden (goldenPath </> "conway" </> "txout-full.json") txOutConwayFull
+
+  -- Dijkstra TxOut tests
+  writeGolden (goldenPath </> "dijkstra" </> "txout-simple.json") txOutDijkstraSimple
+  writeGolden (goldenPath </> "dijkstra" </> "txout-inlinedatum.json") txOutDijkstraInlineDatum
+
+  -- TxOutValue tests
+  writeGolden (goldenPath </> "conway" </> "txoutvalue-lovelace.json") txOutValueConwayLovelace
+  writeGolden (goldenPath </> "conway" </> "txoutvalue-multiasset.json") txOutValueConwayMultiAsset
+  writeGolden (goldenPath </> "dijkstra" </> "txoutvalue-lovelace.json") txOutValueDijkstraLovelace
+
+  -- Address tests
+  writeGolden (goldenPath </> "conway" </> "address.json") (mkTestAddress ShelleyBasedEraConway :: AddressInEra ConwayEra)
+  writeGolden (goldenPath </> "dijkstra" </> "address.json") (mkTestAddress ShelleyBasedEraDijkstra :: AddressInEra DijkstraEra)
+
+  -- ReferenceScript tests
+  writeGolden (goldenPath </> "conway" </> "referencescript.json") (mkTestReferenceScript ShelleyBasedEraConway)
+  writeGolden (goldenPath </> "dijkstra" </> "referencescript.json") (mkTestReferenceScript ShelleyBasedEraDijkstra)
+
+  -- UTxO test
+  writeGolden (goldenPath </> "conway" </> "utxo.json") utxoConway
+
+  putStrLn "Golden files generated successfully!"
+
+writeGolden :: ToJSON a => FilePath -> a -> IO ()
+writeGolden path value = do
+  BL.writeFile path (encodePretty value)
+  putStrLn $ "Wrote: " <> path
+
+-- Test data construction helpers
+
+mkTestAddress :: ShelleyBasedEra era -> AddressInEra era
+mkTestAddress sbe =
+  shelleyAddressInEra sbe $
+    makeShelleyAddress
+      Mainnet
+      (PaymentCredentialByKey testPaymentKeyHash)
+      NoStakeAddress
+
+testPaymentKeyHash :: Hash PaymentKey
+testPaymentKeyHash =
+  fromJust $
+    hush $
+      deserialiseFromRawBytesHex "1c14ee8e58fbcbd48dc7367c95a63fd1d937ba989820015db16ac7e5"
+
+mkLovelaceValue :: ShelleyBasedEra era -> L.Coin -> TxOutValue era
+mkLovelaceValue = lovelaceToTxOutValue
+
+mkMultiAssetValue :: ShelleyBasedEra era -> TxOutValue era
+mkMultiAssetValue sbe =
+  shelleyBasedEraConstraints sbe $
+    TxOutValueShelleyBased sbe $
+      toLedgerValue (maryEraOnwardsToMaryEraOnwards sbe) testMultiAssetValue
+ where
+  maryEraOnwardsToMaryEraOnwards :: ShelleyBasedEra era -> MaryEraOnwards era
+  maryEraOnwardsToMaryEraOnwards = \case
+    ShelleyBasedEraConway -> MaryEraOnwardsConway
+    ShelleyBasedEraDijkstra -> MaryEraOnwardsDijkstra
+    _ -> error "mkMultiAssetValue: unsupported era"
+
+testMultiAssetValue :: Value
+testMultiAssetValue =
+  fromList
+    [ (AdaAssetId, Quantity 2_000_000)
+    , (AssetId testPolicyId testAssetName, Quantity 100)
+    ]
+
+testPolicyId :: PolicyId
+testPolicyId =
+  fromJust $
+    hush $
+      deserialiseFromRawBytesHex "a0000000000000000000000000000000000000000000000000000000"
+
+testAssetName :: AssetName
+testAssetName =
+  fromJust $
+    hush $
+      deserialiseFromRawBytes AsAssetName "TestToken"
+
+testDatumHash :: Hash ScriptData
+testDatumHash =
+  fromJust $
+    hush $
+      deserialiseFromRawBytesHex "ffd29f3e52e7cf2eb451a59448fd55f9c64e4c1ad1ab0e500d6ceb6d7ff97e9c"
+
+testScriptData :: HashableScriptData
+testScriptData =
+  fromJust $
+    hush $
+      deserialiseFromCBOR AsHashableScriptData testScriptDataCBOR
+ where
+  testScriptDataCBOR :: ByteString
+  testScriptDataCBOR = "\24\42"
+
+testSimpleScript :: Script SimpleScript'
+testSimpleScript =
+  SimpleScript $
+    RequireAllOf
+      [ RequireSignature testPaymentKeyHash
+      ]
+
+mkTestReferenceScript :: ShelleyBasedEra era -> ReferenceScript era
+mkTestReferenceScript = \case
+  ShelleyBasedEraConway ->
+    ReferenceScript BabbageEraOnwardsConway (ScriptInAnyLang SimpleScriptLanguage testSimpleScript)
+  ShelleyBasedEraDijkstra ->
+    ReferenceScript BabbageEraOnwardsDijkstra (ScriptInAnyLang SimpleScriptLanguage testSimpleScript)
+  _ -> error "mkTestReferenceScript: unsupported era"
+
+-- TxOut test values
+
+txOutConwaySimple :: TxOut CtxTx ConwayEra
+txOutConwaySimple =
+  TxOut
+    (mkTestAddress ShelleyBasedEraConway)
+    (mkLovelaceValue ShelleyBasedEraConway (L.Coin 1_000_000))
+    TxOutDatumNone
+    ReferenceScriptNone
+
+txOutConwayDatumHash :: TxOut CtxTx ConwayEra
+txOutConwayDatumHash =
+  TxOut
+    (mkTestAddress ShelleyBasedEraConway)
+    (mkLovelaceValue ShelleyBasedEraConway (L.Coin 2_000_000))
+    (TxOutDatumHash AlonzoEraOnwardsConway testDatumHash)
+    ReferenceScriptNone
+
+txOutConwayInlineDatum :: TxOut CtxTx ConwayEra
+txOutConwayInlineDatum =
+  TxOut
+    (mkTestAddress ShelleyBasedEraConway)
+    (mkLovelaceValue ShelleyBasedEraConway (L.Coin 3_000_000))
+    (TxOutDatumInline BabbageEraOnwardsConway testScriptData)
+    ReferenceScriptNone
+
+txOutConwayReferenceScript :: TxOut CtxTx ConwayEra
+txOutConwayReferenceScript =
+  TxOut
+    (mkTestAddress ShelleyBasedEraConway)
+    (mkLovelaceValue ShelleyBasedEraConway (L.Coin 4_000_000))
+    TxOutDatumNone
+    (mkTestReferenceScript ShelleyBasedEraConway)
+
+txOutConwayFull :: TxOut CtxTx ConwayEra
+txOutConwayFull =
+  TxOut
+    (mkTestAddress ShelleyBasedEraConway)
+    (mkMultiAssetValue ShelleyBasedEraConway)
+    (TxOutDatumInline BabbageEraOnwardsConway testScriptData)
+    (mkTestReferenceScript ShelleyBasedEraConway)
+
+txOutDijkstraSimple :: TxOut CtxTx DijkstraEra
+txOutDijkstraSimple =
+  TxOut
+    (mkTestAddress ShelleyBasedEraDijkstra)
+    (mkLovelaceValue ShelleyBasedEraDijkstra (L.Coin 1_000_000))
+    TxOutDatumNone
+    ReferenceScriptNone
+
+txOutDijkstraInlineDatum :: TxOut CtxTx DijkstraEra
+txOutDijkstraInlineDatum =
+  TxOut
+    (mkTestAddress ShelleyBasedEraDijkstra)
+    (mkLovelaceValue ShelleyBasedEraDijkstra (L.Coin 3_000_000))
+    (TxOutDatumInline BabbageEraOnwardsDijkstra testScriptData)
+    (mkTestReferenceScript ShelleyBasedEraDijkstra)
+
+-- TxOutValue test values
+
+txOutValueConwayLovelace :: TxOutValue ConwayEra
+txOutValueConwayLovelace = mkLovelaceValue ShelleyBasedEraConway (L.Coin 5_000_000)
+
+txOutValueConwayMultiAsset :: TxOutValue ConwayEra
+txOutValueConwayMultiAsset = mkMultiAssetValue ShelleyBasedEraConway
+
+txOutValueDijkstraLovelace :: TxOutValue DijkstraEra
+txOutValueDijkstraLovelace = mkLovelaceValue ShelleyBasedEraDijkstra (L.Coin 5_000_000)
+
+-- UTxO test value
+
+utxoConway :: UTxO ConwayEra
+utxoConway =
+  UTxO $
+    fromList
+      [ (testTxIn, txOut1)
+      , (testTxIn2, txOut2)
+      ]
+ where
+  txOut1 :: TxOut CtxUTxO ConwayEra
+  txOut1 =
+    TxOut
+      (mkTestAddress ShelleyBasedEraConway)
+      (mkLovelaceValue ShelleyBasedEraConway (L.Coin 1_000_000))
+      TxOutDatumNone
+      ReferenceScriptNone
+
+  txOut2 :: TxOut CtxUTxO ConwayEra
+  txOut2 =
+    TxOut
+      (mkTestAddress ShelleyBasedEraConway)
+      (mkMultiAssetValue ShelleyBasedEraConway)
+      (TxOutDatumHash AlonzoEraOnwardsConway testDatumHash)
+      ReferenceScriptNone
+
+  testTxIn :: TxIn
+  testTxIn =
+    TxIn testTxId1 (TxIx 0)
+
+  testTxIn2 :: TxIn
+  testTxIn2 =
+    TxIn testTxId2 (TxIx 1)
+
+  testTxId1 :: TxId
+  testTxId1 =
+    fromJust $
+      hush $
+        deserialiseFromRawBytesHex "0000000000000000000000000000000000000000000000000000000000000001"
+
+  testTxId2 :: TxId
+  testTxId2 =
+    fromJust $
+      hush $
+        deserialiseFromRawBytesHex "0000000000000000000000000000000000000000000000000000000000000002"