Re-write balanceTransaction using Node.evaluateTransactionBalance

lib/core-integration/src/Test/Integration/Scenario/API/Shelley/TransactionsNew.hs

@@ -1700,8 +1700,8 @@ spec = describe "NEW_SHELLEY_TRANSACTIONS" $ do
         \Cannot balance when I cannot afford collateral" $
         \ctx -> runResourceT $ do
         wa <- fixtureWalletWith @n ctx
-            [ 2_000_000
-            , 2_000_000
+            [ 2_500_000
+            , 2_500_000
             ]
         let toBalance = Json PlutusScenario.pingPong_1
         rTx <- request @ApiSerialisedTransaction ctx
@@ -1731,11 +1731,11 @@ spec = describe "NEW_SHELLEY_TRANSACTIONS" $ do
             , expectErrorMessage errMsg403Collateral
             , expectErrorMessage $ unwords
                 [ "I need an ada amount of at least:"
-                , "2.779500"
+                , "4.278900"
                 ]
             , expectErrorMessage $ unwords
                 [ "The largest combination of pure ada UTxOs I could find is:"
-                , "[1.853000]"
+                , "[2.852600]"
                 ]
             ]
 
@@ -1847,9 +1847,6 @@ spec = describe "NEW_SHELLEY_TRANSACTIONS" $ do
     it "TRANS_NEW_BALANCE_05/ADP-1286 - \
         \I can balance correctly in case I need to spend my remaining ADA for fee" $
         \ctx -> runResourceT $ do
-        liftIO $ pendingWith
-            "ADP-1286 - ValueNotConservedUTxO: Transaction seems balanced incorrectly \
-            \in case when less than minUtxOValue is left on the wallet"
         wa <- fixtureWalletWith @n ctx [3_000_000]
         -- PlutusScenario.pingPong_1 is sending out 2₳ therefore tx fee
         -- needs to be 1₳ to comply with minUTxOValue constraint

lib/core/src/Cardano/Api/Gen.hs

@@ -39,6 +39,7 @@ module Cardano.Api.Gen
   , genValueForMinting
   , genSignedQuantity
   , genTxMintValue
+  , genSignedValue
   , genNetworkMagic
   , genNetworkId
   , genStakeCredential
@@ -256,8 +257,19 @@ genLovelace = Lovelace <$> frequency
             , (8, pure 65536)
             , (90, pure 4294967296)
             ]
-        x <- choose (-1_000_000, 1_000_000)
-        pure $ max 0 $ boundary + x
+
+        offset <- frequency
+            [ (1, choose (-10, 10))
+
+            -- Offset by values close to common fee values, in both the positive
+            -- and negative direction, with the hope that this helps find
+            -- corner-cases.
+            , (1, choose (-220_000, -150_000))
+            , (1, choose (150_000, 220_000))
+
+            , (1, choose (-1_000_000, 1_000_000))
+            ]
+        pure $ max 0 $ boundary + offset
 
 
 genTxFee :: CardanoEra era -> Gen (TxFee era)
@@ -451,6 +463,24 @@ genValueForTxOut = do
   where
     unLovelace (Lovelace l) = l
 
+-- | Generate a 'Value' which could represent the balance of a partial
+-- transaction, where both ada and other assets can be included, and quantities
+-- can be both positive and negative.
+genSignedValue :: Gen Value
+genSignedValue = do
+    assetIds <- oneof
+        [ nub <$> scale (`div` 4) (listOf genAssetIdNoAda)
+        , pure []
+        ]
+    assetQuantities <- infiniteListOf genSignedQuantity
+    ada <- fromInteger . unLovelace <$> oneof
+        [ genLovelace
+        , negate <$> genLovelace
+        ]
+    return $ valueFromList $ (AdaAssetId, ada) : zip assetIds assetQuantities
+  where
+    unLovelace (Lovelace l) = l
+
 -- | Generate a 'Value' suitable for minting, i.e. non-ADA asset ID and a
 -- positive or negative quantity.
 genValueForMinting :: Gen Value