API includes sort_order, and WebSocket includes data (#19157)

* API includes sort_order, and WebSocket includes data

* Adds sort_order API test

* MM-40470: Tests that new WS payload is sent after categories are updated via API.

* Update api4/channel_category_test.go

Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

Co-authored-by: Martin Kraft <martin@upspin.org>
Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

api4/channel_category_test.go

@@ -4,7 +4,9 @@
 package api4
 
 import (
+	"encoding/json"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -71,6 +73,82 @@ func TestCreateCategoryForTeamForUser(t *testing.T) {
 		assert.NotContains(t, received.Channels, channel.Id)
 		assert.Equal(t, []string{th.BasicChannel.Id}, received.Channels)
 	})
+
+	t.Run("should return expected sort order value", func(t *testing.T) {
+		user, client := setupUserForSubtest(t, th)
+
+		customCategory, _, err := client.CreateSidebarCategoryForTeamForUser(user.Id, th.BasicTeam.Id, &model.SidebarCategoryWithChannels{
+			SidebarCategory: model.SidebarCategory{
+				UserId:      user.Id,
+				TeamId:      th.BasicTeam.Id,
+				DisplayName: "custom123",
+			},
+		})
+		require.NoError(t, err)
+
+		// Initial new category sort order is 10 (first)
+		require.Equal(t, int64(10), customCategory.SortOrder)
+	})
+
+	t.Run("should publish expected WS payload", func(t *testing.T) {
+		userWSClient, err := th.CreateWebSocketClient()
+		require.NoError(t, err)
+		defer userWSClient.Close()
+		userWSClient.Listen()
+
+		category := &model.SidebarCategoryWithChannels{
+			SidebarCategory: model.SidebarCategory{
+				UserId:      th.BasicUser.Id,
+				TeamId:      th.BasicTeam.Id,
+				DisplayName: "test",
+			},
+			Channels: []string{th.BasicChannel.Id, "notachannel", th.BasicChannel2.Id},
+		}
+
+		received, _, err := th.Client.CreateSidebarCategoryForTeamForUser(th.BasicUser.Id, th.BasicTeam.Id, category)
+		require.NoError(t, err)
+
+		testCategories := []*model.SidebarCategoryWithChannels{
+			{
+				SidebarCategory: model.SidebarCategory{
+					Id:      received.Id,
+					UserId:  th.BasicUser.Id,
+					TeamId:  th.BasicTeam.Id,
+					Sorting: model.SidebarCategorySortRecent,
+					Muted:   true,
+				},
+				Channels: []string{th.BasicChannel.Id},
+			},
+		}
+
+		testCategories, _, err = th.Client.UpdateSidebarCategoriesForTeamForUser(th.BasicUser.Id, th.BasicTeam.Id, testCategories)
+		require.NoError(t, err)
+
+		b, err := json.Marshal(testCategories)
+		require.NoError(t, err)
+		expected := string(b)
+
+		var caught bool
+		func() {
+			for {
+				select {
+				case ev := <-userWSClient.EventChannel:
+					if ev.EventType() == model.WebsocketEventSidebarCategoryUpdated {
+						caught = true
+						data := ev.GetData()
+
+						updatedCategoriesData, ok := data["updatedCategories"]
+						require.True(t, ok)
+						require.EqualValues(t, expected, updatedCategoriesData)
+					}
+				case <-time.After(1 * time.Second):
+					return
+				}
+			}
+		}()
+
+		require.Truef(t, caught, "User should have received %s event", model.WebsocketEventSidebarCategoryUpdated)
+	})
 }
 
 func TestUpdateCategoryForTeamForUser(t *testing.T) {