Sqlite: Add pathExists function

The 'pathExists' function can be registered to the database connection
and is then callable in Sql.

Task-number: QDS-9217
Change-Id: I21afc5cd38765854daa0b1058cc5e8946b551924
Reviewed-by: Vikas Pachdha <vikas.pachdha@qt.io>

tests/unit/unittest/sqlitefunctionregistry-test.cpp

@@ -0,0 +1,41 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0+ OR GPL-3.0 WITH Qt-GPL-exception-1.0
+
+#include "googletest.h"
+
+#include <sqlitefunctionregistry.h>
+
+namespace {
+
+class SqliteFunctionRegistry : public testing::Test
+{
+public:
+    SqliteFunctionRegistry() { Sqlite::FunctionRegistry::registerPathExists(database); }
+
+protected:
+    Sqlite::Database database{":memory:", Sqlite::JournalMode::Memory};
+};
+
+TEST_F(SqliteFunctionRegistry, PathExists)
+{
+    std::lock_guard lock{database};
+    Sqlite::ReadStatement<1> statement{"SELECT pathExists('" TESTDATA_DIR "/sqlite_database.db')",
+                                       database};
+
+    auto pathExists = statement.value<bool>();
+
+    ASSERT_TRUE(pathExists);
+}
+
+TEST_F(SqliteFunctionRegistry, PathDoesntExists)
+{
+    std::lock_guard lock{database};
+    Sqlite::ReadStatement<1> statement{"SELECT pathExists('" TESTDATA_DIR "/sqlite_database2.db')",
+                                       database};
+
+    auto pathExists = statement.value<bool>();
+
+    ASSERT_FALSE(pathExists);
+}
+
+} // namespace