Restore examples and tests to use the old balanceAndSignTx interface,…

… add warnings

examples/AlwaysMints.purs

@@ -13,6 +13,7 @@ import Contract.Monad
   , liftContractAffM
   , liftContractM
   , liftedE
+  , liftedM
   , runContract
   )
 import Contract.Prim.ByteArray (byteArrayFromAscii)
@@ -52,7 +53,8 @@ main = launchAff_ $ do
       lookups = Lookups.mintingPolicy mp
 
     ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-    bsTx <- balanceAndSignTx ubTx
+    bsTx <-
+      liftedM "Failed to balance/sign tx" $ balanceAndSignTx ubTx
     txId <- submit bsTx
     logInfo' $ "Tx ID: " <> show txId
 

examples/AlwaysSucceeds.purs

@@ -31,7 +31,7 @@ import Contract.Transaction
   ( TransactionHash
   , TransactionInput(TransactionInput)
   , awaitTxConfirmed
-  , balanceAndSignTx
+  , balanceAndSignTxE
   , submit
   )
 import Contract.TxConstraints (TxConstraints)
@@ -110,7 +110,7 @@ buildBalanceSignAndSubmitTx
   -> Contract () TransactionHash
 buildBalanceSignAndSubmitTx lookups constraints = do
   ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-  bsTx <- balanceAndSignTx ubTx
+  bsTx <- liftedE $ balanceAndSignTxE ubTx
   txId <- submit bsTx
   logInfo' $ "Tx ID: " <> show txId
   pure txId

examples/KeyWallet/MintsAndSendsToken.purs

@@ -7,7 +7,7 @@ module Examples.KeyWallet.MintsAndSendsToken (main) where
 import Contract.Prelude
 
 import Contract.Log (logInfo')
-import Contract.Monad (liftContractAffM, liftContractM, liftedE)
+import Contract.Monad (liftContractAffM, liftContractM, liftedE, liftedM)
 import Contract.Prim.ByteArray (byteArrayFromAscii)
 import Contract.ScriptLookups as Lookups
 import Contract.Transaction (balanceAndSignTx, submit)
@@ -38,7 +38,7 @@ main = runKeyWalletContract_ \pkh lovelace unlock -> do
     lookups = Lookups.mintingPolicy mp
 
   ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-  bsTx <- balanceAndSignTx ubTx
+  bsTx <- liftedM "Failed to balance/sign tx" $ balanceAndSignTx ubTx
   txId <- submit bsTx
   logInfo' $ "Tx ID: " <> show txId
   liftEffect unlock

examples/KeyWallet/Pkh2Pkh.purs

@@ -6,7 +6,7 @@ module Examples.KeyWallet.Pkh2Pkh (main) where
 
 import Contract.Prelude
 
-import Contract.Monad (liftedE)
+import Contract.Monad (liftedE, liftedM)
 import Contract.Log (logInfo')
 import Contract.ScriptLookups as Lookups
 import Contract.Transaction
@@ -31,7 +31,8 @@ main = runKeyWalletContract_ \pkh lovelace unlock -> do
     lookups = mempty
 
   ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-  bsTx <- balanceAndSignTx ubTx
+  bsTx <-
+    liftedM "Failed to balance/sign tx" $ balanceAndSignTx ubTx
   txId <- submit bsTx
   logInfo' $ "Tx ID: " <> show txId
   liftEffect unlock

examples/MintsMultipleTokens.purs

@@ -18,6 +18,7 @@ import Contract.Monad
   , liftContractAffM
   , liftContractM
   , liftedE
+  , liftedM
   , runContract
   )
 import Contract.PlutusData (PlutusData(Integer), Redeemer(Redeemer))
@@ -70,7 +71,8 @@ main = launchAff_ do
           <> Lookups.mintingPolicy mp3
 
     ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-    bsTx <- balanceAndSignTx ubTx
+    bsTx <-
+      liftedM "Failed to balance/sign tx" $ balanceAndSignTx ubTx
     txId <- submit bsTx
     logInfo' $ "Tx ID: " <> show txId
 

examples/Pkh2Pkh.purs

@@ -37,7 +37,8 @@ main = launchAff_ do
       lookups = mempty
 
     ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-    bsTx <- balanceAndSignTx ubTx
+    bsTx <-
+      liftedM "Failed to balance/sign tx" $ balanceAndSignTx ubTx
     txId <- submit bsTx
     logInfo' $ "Tx ID: " <> show txId
     awaitTxConfirmedWithTimeout (wrap 100.0) txId

examples/Pkh2PkhGero.purs

@@ -11,7 +11,7 @@ import Contract.Log (logInfo')
 import Contract.Monad (launchAff_, liftedE, liftedM, runContract)
 import Contract.ScriptLookups as Lookups
 import Contract.Test.E2E (publishTestFeedback)
-import Contract.Transaction (balanceAndSignTx, submit)
+import Contract.Transaction (balanceAndSignTxE, submit)
 import Contract.TxConstraints as Constraints
 import Contract.Value as Value
 import Data.BigInt as BigInt
@@ -34,7 +34,7 @@ main = launchAff_ do
       lookups = mempty
 
     ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-    bsTx <- balanceAndSignTx ubTx
+    bsTx <- liftedE $ balanceAndSignTxE ubTx
     txId <- submit bsTx
     logInfo' $ "Tx ID: " <> show txId
 

src/Contract/Transaction.purs

@@ -6,6 +6,7 @@ module Contract.Transaction
   , awaitTxConfirmedWithTimeout
   , awaitTxConfirmedWithTimeoutSlots
   , balanceAndSignTx
+  , balanceAndSignTxE
   , balanceAndSignTxs
   , balanceTx
   , balanceTxWithAddress
@@ -34,6 +35,7 @@ module Contract.Transaction
   ) where
 
 import Prelude
+import Prim.TypeError (class Warn, Text)
 
 import Aeson (class EncodeAeson, Aeson)
 import BalanceTx (BalanceTxError) as BalanceTxError
@@ -124,7 +126,7 @@ import Data.Time.Duration (Seconds)
 import Data.Traversable (class Traversable, for_, traverse)
 import Data.Tuple.Nested (type (/\))
 import Effect.Class (liftEffect)
-import Effect.Exception (throw)
+import Effect.Exception (Error, throw)
 import Plutus.Conversion (toPlutusCoin, toPlutusTxOutput)
 import Plutus.Conversion.Address (fromPlutusAddress)
 import Plutus.Types.Address (Address)
@@ -376,7 +378,7 @@ withBalancedAndSignedTx
   -> (BalancedSignedTransaction -> Contract r a)
   -> Contract r a
 withBalancedAndSignedTx = withSingleTransaction
-  balanceAndSignTx
+  internalBalanceAndSignTx
   unwrap
 
 -- | Like `balanceTxs`, but uses `balanceTxWithAddress` instead of `balanceTx`
@@ -482,16 +484,30 @@ balanceAndSignTxs txs = balanceTxs txs >>= traverse
 -- | If you want to re-use them in the same 'QueryM' context, call
 -- | `unlockTransactionInputs`.
 balanceAndSignTx
+  :: forall (r :: Row Type)
+   . Warn ( Text "`balanceAndSignTx` no longer returns `Nothing` when failing, instead letting errors continue through the `Contract` monad. `Maybe` will be removed in a future release.")
+  => UnattachedUnbalancedTx
+  -> Contract r (Maybe BalancedSignedTransaction)
+balanceAndSignTx tx = pure <$> internalBalanceAndSignTx tx
+
+internalBalanceAndSignTx
   :: forall (r :: Row Type)
    . UnattachedUnbalancedTx
   -> Contract r BalancedSignedTransaction
-balanceAndSignTx tx = balanceAndSignTxs [ tx ] >>=
+internalBalanceAndSignTx tx = balanceAndSignTxs [ tx ] >>=
   case _ of
     [ x ] -> pure x
-    -- Which error should we throw here?
     _ -> liftEffect $ throw $
       "Unexpected internal error during transaction signing"
 
+-- TODO Deprecate `balanceAndSignTxE` once `Maybe` is dropped from
+-- `balanceAndSignTx`, like in `internalBalanceAndSignTx`.
+balanceAndSignTxE
+  :: forall (r :: Row Type)
+   . UnattachedUnbalancedTx
+  -> Contract r (Either Error BalancedSignedTransaction)
+balanceAndSignTxE = try <<< internalBalanceAndSignTx
+
 scriptOutputToTransactionOutput
   :: NetworkId
   -> UnbalancedTx.ScriptOutput

test/Plutip.purs

@@ -36,6 +36,7 @@ import Contract.Transaction
   , DataHash
   , awaitTxConfirmed
   , balanceAndSignTx
+  , balanceAndSignTxE
   , getTxByHash
   , submit
   , withBalancedAndSignedTxs
@@ -181,7 +182,8 @@ suite = do
             lookups :: Lookups.ScriptLookups Void
             lookups = mempty
           ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-          bsTx <- balanceAndSignTx ubTx
+          bsTx <-
+            liftedE $ balanceAndSignTxE ubTx
           submitAndLog bsTx
 
     test "runPlutipContract: parallel Pkh2Pkh" do
@@ -211,7 +213,8 @@ suite = do
               lookups :: Lookups.ScriptLookups Void
               lookups = mempty
             ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-            bsTx <- balanceAndSignTx ubTx
+            bsTx <-
+              liftedE $ balanceAndSignTxE ubTx
             submitAndLog bsTx
           parallel $ runContractInEnv env $ withKeyWallet bob do
             alicePkh <- liftedM "Failed to get PKH" $ withKeyWallet alice
@@ -228,7 +231,8 @@ suite = do
               lookups :: Lookups.ScriptLookups Void
               lookups = mempty
             ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-            bsTx <- balanceAndSignTx ubTx
+            bsTx <-
+              liftedE $ balanceAndSignTxE ubTx
             submitAndLog bsTx
           in unit
 
@@ -257,7 +261,8 @@ suite = do
             lookups = Lookups.mintingPolicy mp
 
           ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-          bsTx <- balanceAndSignTx ubTx
+          bsTx <-
+            liftedM "Failed to balance/sign tx" $ balanceAndSignTx ubTx
           submitAndLog bsTx
 
     test "runPlutipContract: Datums" do
@@ -314,7 +319,8 @@ suite = do
                 <> Lookups.mintingPolicy mp3
 
           ubTx <- liftedE $ Lookups.mkUnbalancedTx lookups constraints
-          bsTx <- balanceAndSignTx ubTx
+          bsTx <-
+            liftedM "Failed to balance/sign tx" $ balanceAndSignTx ubTx
           submitAndLog bsTx
 
     test "runPlutipContract: SignMultiple" do