From 51d721ee1bea940e8727a9a721e6027e3879fc81 Mon Sep 17 00:00:00 2001
From: Ilya Silchenkov <gitrus@yandex.ru>
Date: Mon, 9 Jun 2025 13:23:39 +0300
Subject: [PATCH] sessionmanager: test version mismatch on Set

---
 pkg/sessionmanager/sessioninmem_test.go | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/pkg/sessionmanager/sessioninmem_test.go b/pkg/sessionmanager/sessioninmem_test.go
index de5c171..4b46c66 100644
--- a/pkg/sessionmanager/sessioninmem_test.go
+++ b/pkg/sessionmanager/sessioninmem_test.go
@@ -110,3 +110,27 @@ func TestUserSessionManagerInMem_FetchEmpty(t *testing.T) {
 		Reason: "user session not found for user ID 456",
 	}, err)
 }
+
+func TestUserSessionManagerInMem_SetVersionMismatch(t *testing.T) {
+	ctx := context.Background()
+	manager := sessionmanager.NewUserSessionManagerInMem[*MockSession](NewMockSession)
+	assert.NotNil(t, manager)
+	userID := int64(789)
+	state, err := manager.InitSession(ctx, userID)
+	assert.NoError(t, err)
+	assert.Equal(t, &MockSession{}, state)
+
+	// act
+	newSession := &MockSession{State: "action", version: 2}
+	updatedState, err := manager.Set(ctx, userID, newSession, 1)
+
+	// assert
+	assert.Error(t, err)
+	assert.Equal(t, sessionmanager.ErrSessionManagement{Reason: "version mismatch"}, err)
+	assert.Equal(t, state, updatedState)
+
+	// verify stored session remains unchanged
+	fetchedState, err := manager.Fetch(ctx, userID)
+	assert.NoError(t, err)
+	assert.Equal(t, state, fetchedState)
+}