Added one important test (#7683)

* Added one important test

* Update app/actions/local/category.test.ts

---------

Co-authored-by: Elias Nahum <nahumhbl@gmail.com>

app/actions/local/category.test.ts

@@ -0,0 +1,69 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import DatabaseManager from '@database/manager';
+
+import {handleConvertedGMCategories} from './category';
+
+import type ServerDataOperator from '@database/operator/server_data_operator';
+
+describe('handleConvertedGMCategories', () => {
+    const serverUrl = 'baseHandler.test.com';
+    const channelId = 'channel_id_1';
+    const teamId1 = 'team_id_1';
+    const teamId2 = 'team_id_2';
+    const team: Team = {
+        id: teamId1,
+    } as Team;
+
+    let operator: ServerDataOperator;
+
+    beforeEach(async () => {
+        await DatabaseManager.init([serverUrl]);
+        operator = DatabaseManager.serverDatabases[serverUrl]!.operator;
+    });
+
+    it('base case', async () => {
+        await operator.handleTeam({teams: [team], prepareRecordsOnly: false});
+
+        const defaultCategory: Category = {
+            id: 'default_category_id',
+            team_id: teamId1,
+            type: 'channels',
+        } as Category;
+
+        const customCategory: Category = {
+            id: 'custom_category_id',
+            team_id: teamId2,
+            type: 'custom',
+        } as Category;
+
+        const dmCategory: Category = {
+            id: 'dm_category_id',
+            team_id: teamId1,
+            type: 'direct_messages',
+        } as Category;
+
+        await operator.handleCategories({categories: [defaultCategory, customCategory, dmCategory], prepareRecordsOnly: false});
+
+        const dmCategoryChannel: CategoryChannel = {
+            id: 'dm_category_channel_id',
+            category_id: 'dm_category_id',
+            channel_id: channelId,
+            sort_order: 1,
+        };
+
+        const customCategoryChannel: CategoryChannel = {
+            id: 'custom_category_channel_id',
+            category_id: 'dm_category_id',
+            channel_id: channelId,
+            sort_order: 1,
+        };
+        await operator.handleCategoryChannels({categoryChannels: [dmCategoryChannel, customCategoryChannel], prepareRecordsOnly: false});
+
+        const {models, error} = await handleConvertedGMCategories(serverUrl, channelId, teamId1, true);
+        expect(error).toBeUndefined();
+        expect(models).toBeDefined();
+        expect(models!.length).toBe(3); // two for removing channel for a custom and a DM category, and one for adding it to default channels category
+    });
+});

app/actions/local/category.ts

@@ -134,8 +134,9 @@ export async function handleConvertedGMCategories(serverUrl: string, channelId:
         const channelCategory = categories.find((category) => category.type === CHANNELS_CATEGORY);
 
         if (!channelCategory) {
-            logError('Failed to find default category when handling category of converted GM');
-            return {};
+            const error = 'Failed to find default category when handling category of converted GM';
+            logError(error);
+            return {error};
         }
 
         const models: Model[] = [];