CORDA-1548 Hibernate session not flushed before handing over raw JDBC session to user code (e.g. coin selection) (#3266)

* Hibernate session flushed before handing over raw JDBC session to user code + test - inserting and selecting cash in the same transaction
* Additional two tests copied from Enterprise repo

finance/src/integration-test/kotlin/net/corda/finance/flows/CashSelectionTest.kt

@@ -1,10 +1,18 @@
 package net.corda.finance.flows
 
+import net.corda.core.contracts.TransactionState
+import net.corda.core.contracts.withoutIssuer
+import net.corda.core.identity.Party
 import net.corda.core.messaging.startFlow
+import net.corda.core.transactions.TransactionBuilder
 import net.corda.core.utilities.OpaqueBytes
 import net.corda.core.utilities.getOrThrow
 import net.corda.finance.DOLLARS
+import net.corda.finance.contracts.asset.Cash
+import net.corda.finance.contracts.asset.cash.selection.AbstractCashSelection
 import net.corda.finance.contracts.getCashBalance
+import net.corda.finance.issuedBy
+import net.corda.testing.core.singleIdentity
 import net.corda.testing.driver.DriverParameters
 import net.corda.testing.driver.driver
 import net.corda.testing.driver.internal.InProcessImpl
@@ -34,4 +42,97 @@ class CashSelectionTest {
             assertThat(availableBalanceAfterExit).isEqualTo(issuedAmount - exitedAmount)
         }
     }
+
+    @Test
+    fun `cash selection sees states added in the same transaction`() {
+        driver(DriverParameters(startNodesInProcess = true, extraCordappPackagesToScan = listOf("net.corda.finance"))) {
+            val node = startNode().getOrThrow() as InProcessImpl
+            val nodeIdentity = node.services.myInfo.singleIdentity()
+            val issuer = nodeIdentity.ref(1)
+            val coin = 1.DOLLARS.issuedBy(issuer)
+            val exitedAmount = 1.DOLLARS
+            val issuance = TransactionBuilder(null as Party?)
+            issuance.addOutputState(TransactionState(Cash.State(coin, nodeIdentity), Cash.PROGRAM_ID, defaultNotaryIdentity))
+            issuance.addCommand(Cash.Commands.Issue(), nodeIdentity.owningKey)
+
+            //insert ans select in the same transaction
+            val exitStates = node.database.transaction {
+
+                val transaction = node.services.signInitialTransaction(issuance, nodeIdentity.owningKey)
+                node.services.recordTransactions(transaction)
+
+                val builder = TransactionBuilder(notary = null)
+                AbstractCashSelection
+                        .getInstance { node.services.jdbcSession().metaData }
+                        .unconsumedCashStatesForSpending(node.services, exitedAmount, setOf(issuer.party), builder.notary, builder.lockId, setOf(issuer.reference))
+            }
+            val returnedCoinsNumber = 1
+            assertThat(exitStates.size).isEqualTo(returnedCoinsNumber)
+        }
+    }
+
+    @Test
+    fun `dont return extra coins if the selected amount has been reached`() {
+        driver(DriverParameters(startNodesInProcess = true, extraCordappPackagesToScan = listOf("net.corda.finance"))) {
+            val node = startNode().getOrThrow() as InProcessImpl
+            val nodeIdentity = node.services.myInfo.singleIdentity()
+
+            val issuer = nodeIdentity.ref(1)
+
+            val exitStates = node.database.transaction {
+                //issue $1 coin twice
+                repeat(2, {
+                    val coin = 1.DOLLARS.issuedBy(issuer)
+                    val issuance = TransactionBuilder(null as Party?)
+                    issuance.addOutputState(TransactionState(Cash.State(coin, nodeIdentity), Cash.PROGRAM_ID, defaultNotaryIdentity))
+                    issuance.addCommand(Cash.Commands.Issue(), nodeIdentity.owningKey)
+
+                    val transaction = node.services.signInitialTransaction(issuance, nodeIdentity.owningKey)
+
+                    node.services.recordTransactions(transaction)
+                })
+
+                val exitedAmount = 1.DOLLARS
+                val builder = TransactionBuilder(notary = null)
+                AbstractCashSelection
+                        .getInstance { node.services.jdbcSession().metaData }
+                        .unconsumedCashStatesForSpending(node.services, exitedAmount, setOf(issuer.party), builder.notary, builder.lockId, setOf(issuer.reference))
+            }
+            val returnedCoinsNumber = 1
+            assertThat(exitStates.size).isEqualTo(returnedCoinsNumber)
+        }
+    }
+
+    @Test
+    fun `select cash states issued by single transaction and give change`() {
+        driver(DriverParameters(startNodesInProcess = true, extraCordappPackagesToScan = listOf("net.corda.finance"))) {
+            val node = startNode().getOrThrow() as InProcessImpl
+            val nodeIdentity = node.services.myInfo.singleIdentity()
+
+            val coins = listOf(3.DOLLARS, 2.DOLLARS, 1.DOLLARS).map { it.issuedBy(nodeIdentity.ref(1)) }
+
+            //create single transaction with 3 cash outputs
+            val issuance = TransactionBuilder(null as Party?)
+            coins.map { issuance.addOutputState(TransactionState(Cash.State(it, nodeIdentity), "net.corda.finance.contracts.asset.Cash", defaultNotaryIdentity)) }
+            issuance.addCommand(Cash.Commands.Issue(), nodeIdentity.owningKey)
+
+            val transaction = node.services.signInitialTransaction(issuance, nodeIdentity.owningKey)
+            node.database.transaction {
+                node.services.recordTransactions(transaction)
+            }
+
+            val issuedAmount = coins.reduce { sum, element -> sum + element }.withoutIssuer()
+
+                val availableBalance = node.rpc.getCashBalance(issuedAmount.token)
+
+                assertThat(availableBalance).isEqualTo(issuedAmount)
+
+            val exitedAmount = 3.01.DOLLARS
+                node.rpc.startFlow(::CashExitFlow, exitedAmount, OpaqueBytes.of(1)).returnValue.getOrThrow()
+
+            val availableBalanceAfterExit = node.rpc.getCashBalance(issuedAmount.token)
+
+            assertThat(availableBalanceAfterExit).isEqualTo(issuedAmount - exitedAmount)
+        }
+    }
 }

node-api/src/main/kotlin/net/corda/nodeapi/internal/persistence/CordaPersistence.kt

@@ -105,6 +105,7 @@ class CordaPersistence(
     fun createSession(): Connection {
         // We need to set the database for the current [Thread] or [Fiber] here as some tests share threads across databases.
         _contextDatabase.set(this)
+        currentDBSession().flush()
         return contextTransaction.connection
     }