[-] fix pool after release handler to avoid session termination causi…

…ng side effects (#615)

* [-] fix pool after release handler to avoid session termination causing side effects
* [-] deallocate all internal prepared statements before DISCARD
* [-] fix `migrateTest` to close opened `pgengine`

internal/migrator/migrator_test.go

@@ -55,6 +55,7 @@ func migrateTest() error {
 	if err != nil {
 		return err
 	}
+	defer pge.Finalize()
 	_, _ = pge.ConfigDb.Exec(ctx, "DROP TABLE IF EXISTS foo, bar, baz, migration")
 	db, err := pge.ConfigDb.Acquire(ctx)
 	if err != nil {

internal/pgengine/bootstrap.go

@@ -184,10 +184,13 @@ func (pge *PgEngine) getPgxConnConfig() *pgxpool.Config {
 	// some objects and/or setting changes will still exist in the session
 	connConfig.AfterRelease = func(pgconn *pgx.Conn) bool {
 		var err error
+		if pgconn.DeallocateAll(context.Background()) != nil {
+			return false // destroy the connection in case of error
+		}
 		if _, err = pgconn.Exec(context.Background(), "DISCARD ALL"); err == nil {
 			_, err = pgconn.Exec(context.Background(), "LISTEN "+quoteIdent(pge.ClientName))
 		}
-		return err != nil
+		return err == nil
 	}
 
 	if !pge.Start.Debug { //will handle notification in HandleNotifications directly