diff --git a/FVAViewer/CMakeLists.txt b/FVAViewer/CMakeLists.txt
index fd6e2bc5..6a536097 100644
--- a/FVAViewer/CMakeLists.txt
+++ b/FVAViewer/CMakeLists.txt
@@ -13,6 +13,8 @@ set(HEADER_FILES
     ../FVACommonLib/FVADescriptionFile.h
 )
 
+add_subdirectory(test)
+
 # IMPORTANT: once you add new implementation file here please update IMPLEMENTATIONSTATUS.MD as well in the current folder 
 add_executable(fvaviewer 
     d-filter.ui
diff --git a/FVAViewer/test/CMakeLists.txt b/FVAViewer/test/CMakeLists.txt
new file mode 100644
index 00000000..bd98c6fc
--- /dev/null
+++ b/FVAViewer/test/CMakeLists.txt
@@ -0,0 +1,22 @@
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+find_package(Qt5 COMPONENTS Core Gui Widgets REQUIRED)
+
+# tests source files here
+add_executable(fvaviewertests
+  test_fvaviewer.cpp
+)
+
+# add includes
+target_include_directories(fvaviewerlibtests PRIVATE 
+../../FVACommonLib
+../../FVAFlowController)
+
+# Link GoogleTest tests and other libs
+target_link_libraries(fvaviewertests Qt5::Widgets Qt5::Core Qt5::Gui gtest gtest_main fvalib)
+
+# Add the tests to CTest's test runner
+add_test(NAME fvaviewertests COMMAND fvaviewertests)
+
diff --git a/FVAViewer/test/test_fvaviewer.cpp b/FVAViewer/test/test_fvaviewer.cpp
new file mode 100644
index 00000000..a45110f4
--- /dev/null
+++ b/FVAViewer/test/test_fvaviewer.cpp
@@ -0,0 +1,180 @@
+#include <gtest/gtest.h>
+#include <gmock/gmock.h>
+
+#include "fvaviewer.h"
+
+// Mock class for QDir
+class MockQDir : public QDir {
+public:
+    MOCK_METHOD1(exists, bool(const QString&));
+};
+
+// Mock class for QProgressDialog
+class MockQProgressDialog : public QProgressDialog {
+public:
+    MOCK_METHOD2(setValue, void(int));
+};
+
+// Test fixture for FVAViewer tests
+class FVAViewerTest : public ::testing::Test {
+protected:
+    void SetUp() override {
+        // Initialize the FVAViewer object
+        viewer = new FVAViewer;
+    }
+
+    void TearDown() override {
+        // Clean up the FVAViewer object
+        delete viewer;
+    }
+
+    FVAViewer* viewer;
+};
+
+// Test case for showProgress when the directory exists
+TEST_F(FVAViewerTest, ShowProgress_DirectoryExists) {
+    // Arrange
+    QString rootDir = "/path/to/directory";
+    MockQDir mockDir;
+    EXPECT_CALL(mockDir, exists(rootDir)).WillOnce(::testing::Return(true));
+    viewer->setDir(&mockDir);
+
+    // Act
+    viewer->showProgress(rootDir);
+
+    // Assert
+    // Add your assertions here
+}
+
+// Test case for showProgress when the directory does not exist
+TEST_F(FVAViewerTest, ShowProgress_DirectoryDoesNotExist) {
+    // Arrange
+    QString rootDir = "/path/to/nonexistent_directory";
+    MockQDir mockDir;
+    EXPECT_CALL(mockDir, exists(rootDir)).WillOnce(::testing::Return(false));
+    viewer->setDir(&mockDir);
+
+    // Act
+    viewer->showProgress(rootDir);
+
+    // Assert
+    // Add your assertions here
+}
+
+// Test case for showProgress when the number of items is zero
+TEST_F(FVAViewerTest, ShowProgress_ZeroItems) {
+    // Arrange
+    QString rootDir = "/path/to/directory";
+    MockQDir mockDir;
+    EXPECT_CALL(mockDir, exists(rootDir)).WillOnce(::testing::Return(true));
+    viewer->setDir(&mockDir);
+
+    MockQProgressDialog mockProgress;
+    EXPECT_CALL(mockProgress, setValue(0));
+    viewer->setProgressDialog(&mockProgress);
+
+    // Act
+    viewer->showProgress(rootDir);
+
+    // Assert
+    // Add your assertions here
+}
+
+// Test case for showProgress when the number of items is non-zero
+TEST_F(FVAViewerTest, ShowProgress_NonZeroItems) {
+    // Arrange
+    QString rootDir = "/path/to/directory";
+    MockQDir mockDir;
+    EXPECT_CALL(mockDir, exists(rootDir)).WillOnce(::testing::Return(true));
+    viewer->setDir(&mockDir);
+
+    MockQProgressDialog mockProgress;
+    EXPECT_CALL(mockProgress, setValue(::testing::_));
+    viewer->setProgressDialog(&mockProgress);
+
+    // Act
+    viewer->showProgress(rootDir);
+
+    // Assert
+    // Add your assertions here
+}
+// Test case for FVAViewer constructor
+TEST_F(FVAViewerTests, Constructor)
+{
+    // Arrange
+    QString rootDir = "/path/to/root";
+    QString dictPath = "/path/to/dictionary";
+
+    // Act
+    FVAViewer viewer(rootDir, dictPath);
+
+    // Assert
+    // Verify that the viewer is constructed correctly
+    // Add assertions to verify the expected behavior and output
+}
+
+// Test case for populateGUITree function
+TEST_F(FVAViewerTests, PopulateGUITree)
+{
+    // Arrange
+    FVAViewer viewer;
+    fvaItem fvaItem; // Set up the necessary fvaItem for the test
+    QTreeWidgetItem item; // Set up the necessary QTreeWidgetItem for the test
+    int number = 0;
+    QProgressDialog progress; // Set up the necessary QProgressDialog for the test
+
+    // Act
+    viewer.populateGUITree(&fvaItem, &item, number, &progress);
+
+    // Assert
+    // Verify that the GUI tree is populated correctly
+    // Add assertions to verify the expected behavior and output
+}
+
+// Test case for showProgress function
+TEST_F(FVAViewerTests, ShowProgress)
+{
+    // Arrange
+    FVAViewer viewer;
+    QString rootDir = "/path/to/root";
+
+    // Act
+    viewer.showProgress(rootDir);
+
+    // Assert
+    // Verify that the progress is shown correctly
+    // Add assertions to verify the expected behavior and output
+}
+
+// Test case for prepareFilters function
+TEST_F(FVAViewerTests, PrepareFilters)
+{
+    // Arrange
+    FVAViewer viewer;
+
+    // Act
+    viewer.prepareFilters();
+
+    // Assert
+    // Verify that the filters are initialized correctly
+    // Add assertions to verify the expected behavior and output
+}
+
+// Test case for fvaFilterTree function
+TEST_F(FVAViewerTests, FvaFilterTree)
+{
+    // Arrange
+    FVAViewer viewer;
+    fvaFilter filter; // Set up the necessary filter for the test
+    fvaItem fvaItem; // Set up the necessary fvaItem for the test
+    QDateTime defFilterDataTime; // Set up the necessary defFilterDataTime for the test
+
+    // Act
+    viewer.fvaFilterTree(filter, &fvaItem, defFilterDataTime);
+
+    // Assert
+    // Verify that the FVA tree is filtered correctly
+    // Add assertions to verify the expected behavior and output
+}
+
+// Add more test cases for other member functions as needed
\ No newline at end of file