Address review feedback on babbageOnwardsTxOutParseJson and test coverage

Fail when inlineDatumhash is present without inlineDatumRaw, symmetric with
the existing check for the opposite case. Correct the Haddock and add an
explanatory comment for the Dijkstra skip in prop_new_txout_json_roundtrip.

Author: Jimbo4350

cardano-api/src/Cardano/Api/Experimental/Tx/Internal/BodyContent/New.hs

@@ -580,9 +580,12 @@ babbageOnwardsTxOutParseJson o = do
             <> ", got "
             <> show (L.hashBinaryData binaryData)
       pure $ L.Datum binaryData
-    Nothing -> case mDatumHash of
-      Just dh -> pure $ L.DatumHash dh
-      Nothing -> pure L.NoDatum
+    Nothing -> do
+      when (isJust mInlineDatumHash) $
+        fail "babbageOnwardsTxOutParseJson: inlineDatumhash present without inlineDatumRaw"
+      case mDatumHash of
+        Just dh -> pure $ L.DatumHash dh
+        Nothing -> pure L.NoDatum
   -- Determine reference script
   refScript <- case mRefScript of
     Nothing -> pure SNothing

cardano-api/test/cardano-api-test/Test/Cardano/Api/Json.hs

@@ -94,7 +94,8 @@ go sbe = do
   toJSON oldTxOut === toJSON newTxOut
 
 -- | Verify that the new experimental 'TxOut' round-trips through JSON
--- (encode then decode) for all Shelley-based eras.
+-- (encode then decode) for all Shelley-based eras except Dijkstra, for which
+-- 'shelleyBasedEraConstraints' is not yet implemented.
 prop_new_txout_json_roundtrip :: Property
 prop_new_txout_json_roundtrip = H.property $ do
   AnyShelleyBasedEra sbe <- forAll $ Gen.element [minBound .. maxBound]
@@ -105,7 +106,7 @@ prop_new_txout_json_roundtrip = H.property $ do
     ShelleyBasedEraAlonzo -> goRoundtrip sbe
     ShelleyBasedEraBabbage -> goRoundtrip sbe
     ShelleyBasedEraConway -> goRoundtrip sbe
-    ShelleyBasedEraDijkstra -> pure ()
+    ShelleyBasedEraDijkstra -> pure () -- shelleyBasedEraConstraints not yet implemented
 
 goRoundtrip
   :: ( L.EraTxOut (ShelleyLedgerEra era)