[MM-42191]: Include deleted posts (#19985)

* MM-42191: Include deleted posts: Add includeDeleted query parameter for getPostsForChannel

* MM-42191: Fix error typo for includeDeleted query parameter

* MM-42191: Include deleted posts: Set permission error when deleted posts are requested by non system admins

* MM-42191: Include deleted posts: Refactor replyCountSubQuery and conditions when includeDeleted is not presented, refactor getRootPosts

* MM-42191: Include deleted posts: Refactor getRootPosts function along with skipFetchThreads and includeDeleted

* MM-42191: Include deleted posts: Rename includeDeleted to include_deleted param

* MM-42191: Include deleted posts: Fix failed posts unit tests

* MM-42191: Include deleted posts: Add missing include deleted option in multiple queries

* MM-42191: Include deleted posts: Add tests for include deleted option in TestGetPostsForChannel, TestGetPostsBefore, TestGetPostsAfter

* MM-42191: include deleted posts: Add tests cases for post store test

* MM-42191: Include deleted posts: Add extra unit test to ensure not returning deleted posts when IncludeDelete is false

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/storetest/post_store.go

@@ -1946,6 +1946,73 @@ func testPostStoreGetPosts(t *testing.T, ss store.Store) {
 		assert.Equal(t, int64(1), postList.Posts[post5.Id].ReplyCount)
 		assert.Equal(t, int64(1), postList.Posts[post6.Id].ReplyCount)
 	})
+
+	t.Run("should return all posts in a channel included deleted posts", func(t *testing.T) {
+		err := ss.Post().Delete(post1.Id, 1, userId)
+		require.NoError(t, err)
+
+		postList, err := ss.Post().GetPosts(model.GetPostsOptions{ChannelId: channelId, Page: 0, PerPage: 30, SkipFetchThreads: false, IncludeDeleted: true}, false, map[string]bool{})
+		require.NoError(t, err)
+
+		assert.Equal(t, []string{
+			post6.Id,
+			post5.Id,
+			post4.Id,
+			post3.Id,
+			post2.Id,
+			post1.Id,
+		}, postList.Order)
+
+		assert.Len(t, postList.Posts, 6)
+		assert.NotNil(t, postList.Posts[post1.Id])
+		assert.NotNil(t, postList.Posts[post2.Id])
+		assert.NotNil(t, postList.Posts[post3.Id])
+		assert.NotNil(t, postList.Posts[post4.Id])
+		assert.NotNil(t, postList.Posts[post5.Id])
+		assert.NotNil(t, postList.Posts[post6.Id])
+	})
+
+	t.Run("should return all posts in a channel included deleted posts without threads", func(t *testing.T) {
+		err := ss.Post().Delete(post5.Id, 1, userId)
+		require.NoError(t, err)
+
+		postList, err := ss.Post().GetPosts(model.GetPostsOptions{ChannelId: channelId, Page: 0, PerPage: 30, SkipFetchThreads: true, IncludeDeleted: true}, false, map[string]bool{})
+		require.NoError(t, err)
+
+		assert.Equal(t, []string{
+			post6.Id,
+			post5.Id,
+			post4.Id,
+			post3.Id,
+			post2.Id,
+			post1.Id,
+		}, postList.Order)
+
+		assert.Len(t, postList.Posts, 6)
+		assert.NotNil(t, postList.Posts[post5.Id])
+		assert.NotNil(t, postList.Posts[post6.Id])
+		assert.Equal(t, int64(1), postList.Posts[post5.Id].ReplyCount)
+		assert.Equal(t, int64(1), postList.Posts[post6.Id].ReplyCount)
+	})
+
+	t.Run("should return the lasts posts created in channel without include deleted posts", func(t *testing.T) {
+		err := ss.Post().Delete(post6.Id, 1, userId)
+		require.NoError(t, err)
+
+		postList, err := ss.Post().GetPosts(model.GetPostsOptions{ChannelId: channelId, Page: 0, PerPage: 30, SkipFetchThreads: true, IncludeDeleted: false}, false, map[string]bool{})
+		require.NoError(t, err)
+
+		assert.Equal(t, []string{
+			post4.Id,
+			post3.Id,
+			post2.Id,
+		}, postList.Order)
+
+		assert.Len(t, postList.Posts, 3)
+		assert.NotNil(t, postList.Posts[post2.Id])
+		assert.NotNil(t, postList.Posts[post3.Id])
+		assert.NotNil(t, postList.Posts[post4.Id])
+	})
 }
 
 func testPostStoreGetPostBeforeAfter(t *testing.T, ss store.Store) {