Make functions altering transaction state lenient in on demand mode (#83)

The database is read only anyway in the on demand mode, so it's alright.

Author: arybczak

CHANGELOG.md

@@ -1,3 +1,7 @@
+# hpqtypes-1.14.0.0 (2025-??-??)
+* Make `begin`, `commit` and `rollback` do nothing instead of throwing an error
+  if the on demand connection acquisition mode is active.
+
 # hpqtypes-1.13.0.1 (2025-11-27)
 * Fix a bug in `initConnectionState` and `finalizeConnectionState` that could
   lead to leaking connections.

hpqtypes.cabal

@@ -1,7 +1,7 @@
 cabal-version:       3.0
 build-type:          Simple
 name:                hpqtypes
-version:             1.13.0.1
+version:             1.14.0.0
 synopsis:            Haskell bindings to libpqtypes
 
 description:         Efficient and easy-to-use bindings to (slightly modified)

src/Database/PostgreSQL/PQTypes/Transaction.hs

@@ -56,8 +56,7 @@ withSavepoint (Savepoint savepoint) m =
 begin :: (HasCallStack, MonadDB m, MonadMask m) => m ()
 begin = do
   getConnectionAcquisitionMode >>= \case
-    AcquireOnDemand -> do
-      throwDB $ HPQTypesError "Can't begin a transaction in OnDemand mode"
+    AcquireOnDemand -> pure ()
     AcquireAndHold isolationLevel permissions -> uninterruptibleMask_ $ do
       runSQL_ $
         smconcat
@@ -77,8 +76,7 @@ begin = do
 commit :: (HasCallStack, MonadDB m, MonadMask m) => m ()
 commit = do
   getConnectionAcquisitionMode >>= \case
-    AcquireOnDemand -> do
-      throwDB $ HPQTypesError "Can't commit a transaction in OnDemand mode"
+    AcquireOnDemand -> pure ()
     AcquireAndHold {} -> uninterruptibleMask_ $ do
       runSQL_ "COMMIT"
       begin
@@ -87,8 +85,7 @@ commit = do
 rollback :: (HasCallStack, MonadDB m, MonadMask m) => m ()
 rollback = do
   getConnectionAcquisitionMode >>= \case
-    AcquireOnDemand -> do
-      throwDB $ HPQTypesError "Can't rollback a transaction in OnDemand mode"
+    AcquireOnDemand -> pure ()
     AcquireAndHold {} -> uninterruptibleMask_ $ do
       runSQL_ "ROLLBACK"
       begin