[MM-51089] Fix sorting value of category in CreateSidebarCategoryForTeamForUser (#22455)

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/store/sqlstore/channel_store_categories.go

@@ -335,7 +335,7 @@ func (s SqlChannelStore) CreateSidebarCategory(userId, teamId string, newCategor
 		Id:          newCategoryId,
 		UserId:      userId,
 		TeamId:      teamId,
-		Sorting:     model.SidebarCategorySortDefault,
+		Sorting:     newCategory.Sorting,
 		SortOrder:   int64(model.MinimalSidebarSortDistance * len(newOrder)), // first we place it at the end of the list
 		Type:        model.SidebarCategoryCustom,
 		Muted:       newCategory.Muted,

server/channels/store/storetest/channel_store_categories.go

@@ -672,6 +672,38 @@ func testCreateSidebarCategory(t *testing.T, ss store.Store) {
 		require.NoError(t, err)
 		assert.Equal(t, []string{}, res2.Channels)
 	})
+
+	t.Run("should store the correct sorting value", func(t *testing.T) {
+		userId := model.NewId()
+
+		team := setupTeam(t, ss, userId)
+
+		opts := &store.SidebarCategorySearchOpts{
+			TeamID:      team.Id,
+			ExcludeTeam: false,
+		}
+		res, nErr := ss.Channel().CreateInitialSidebarCategories(userId, opts)
+		require.NoError(t, nErr)
+		require.NotEmpty(t, res)
+		// Create the category
+		created, err := ss.Channel().CreateSidebarCategory(userId, team.Id, &model.SidebarCategoryWithChannels{
+			SidebarCategory: model.SidebarCategory{
+				DisplayName: model.NewId(),
+				Sorting:     model.SidebarCategorySortManual,
+			},
+		})
+		require.NoError(t, err)
+
+		// Confirm that sorting value is correct
+		res, err = ss.Channel().GetSidebarCategoriesForTeamForUser(userId, team.Id)
+		require.NoError(t, err)
+		require.Len(t, res.Categories, 4)
+		// first category will be favorites and second will be newly created
+		assert.Equal(t, model.SidebarCategoryCustom, res.Categories[1].Type)
+		assert.Equal(t, created.Id, res.Categories[1].Id)
+		assert.Equal(t, model.SidebarCategorySortManual, res.Categories[1].Sorting)
+		assert.Equal(t, model.SidebarCategorySortManual, created.Sorting)
+	})
 }
 
 func testGetSidebarCategory(t *testing.T, ss store.Store, s SqlStore) {