Test withTransaction

test/Main.purs

@@ -5,8 +5,10 @@ module Test.Main
 import Control.Monad.Aff (launchAff)
 import Control.Monad.Eff (Eff)
 import Control.Monad.Eff.Class (liftEff)
-import Control.Monad.Eff.Exception (EXCEPTION)
-import Database.PostgreSQL (POSTGRESQL, PoolConfiguration, Query(..), Row0(..), Row1(..), Row6(..), execute, newPool, query, withConnection)
+import Control.Monad.Eff.Exception (EXCEPTION, error)
+import Control.Monad.Error.Class (throwError, try)
+import Data.Maybe (Maybe(..))
+import Database.PostgreSQL (POSTGRESQL, PoolConfiguration, Query(..), Row0(..), Row1(..), Row2(..), Row6(..), execute, newPool, query, scalar, withConnection, withTransaction)
 import Prelude
 import Test.Assert (ASSERT, assert)
 
@@ -27,15 +29,51 @@ main = void $ launchAff do
       VALUES ($1, $2), ($3, $4), ($5, $6)
     """) (Row6 "pork" true "sauerkraut" false "rookworst" true)
 
-    query conn (Query """
+    names <- query conn (Query """
       SELECT name
       FROM foods
       WHERE delicious
       ORDER BY name ASC
     """) Row0
-      >>= liftEff <<< assert <<< (==) [Row1 "pork", Row1 "rookworst"]
+    liftEff <<< assert $ names == [Row1 "pork", Row1 "rookworst"]
+
+    testTransactionCommit conn
+    testTransactionRollback conn
 
     pure unit
+  where
+  testTransactionCommit conn = do
+    deleteAll conn
+    withTransaction conn do
+      execute conn (Query """
+        INSERT INTO foods (name, delicious)
+        VALUES ($1, $2)
+      """) (Row2 "pork" true)
+      testCount conn 1
+    testCount conn 1
+
+  testTransactionRollback conn = do
+    deleteAll conn
+    _ <- try $ withTransaction conn do
+      execute conn (Query """
+        INSERT INTO foods (name, delicious)
+        VALUES ($1, $2)
+      """) (Row2 "pork" true)
+      testCount conn 1
+      throwError $ error "fail"
+    testCount conn 0
+
+  deleteAll conn =
+    execute conn (Query """
+      DELETE FROM foods
+    """) Row0
+
+  testCount conn n = do
+    count <- scalar conn (Query """
+      SELECT count(*) = $1
+      FROM foods
+    """) (Row1 n)
+    liftEff <<< assert $ count == Just true
 
 config :: PoolConfiguration
 config =