Remove duplicated entries in users' following lists

test/tasks/database_test.exs

@@ -0,0 +1,49 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Mix.Tasks.Pleroma.DatabaseTest do
+  alias Pleroma.Repo
+  alias Pleroma.User
+  use Pleroma.DataCase
+
+  import Pleroma.Factory
+
+  setup_all do
+    Mix.shell(Mix.Shell.Process)
+
+    on_exit(fn ->
+      Mix.shell(Mix.Shell.IO)
+    end)
+
+    :ok
+  end
+
+  describe "running update_users_following_followers_counts" do
+    test "following and followers count are updated" do
+      [user, user2] = insert_pair(:user)
+      {:ok, %User{following: following, info: info} = user} = User.follow(user, user2)
+
+      assert length(following) == 2
+      assert info.follower_count == 0
+
+      info_cng = Ecto.Changeset.change(info, %{follower_count: 3})
+
+      {:ok, user} =
+        user
+        |> Ecto.Changeset.change(%{following: following ++ following})
+        |> Ecto.Changeset.put_embed(:info, info_cng)
+        |> Repo.update()
+
+      assert length(user.following) == 4
+      assert user.info.follower_count == 3
+
+      assert :ok == Mix.Tasks.Pleroma.Database.run(["update_users_following_followers_counts"])
+
+      user = User.get_by_id(user.id)
+
+      assert length(user.following) == 2
+      assert user.info.follower_count == 0
+    end
+  end
+end

test/tasks/user_test.exs

@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Mix.Tasks.Pleroma.UserTest do
+  alias Pleroma.Repo
   alias Pleroma.User
   use Pleroma.DataCase
 

test/user_test.exs

@@ -626,6 +626,37 @@ defmodule Pleroma.UserTest do
     end
   end
 
+  describe "remove duplicates from following list" do
+    test "it removes duplicates" do
+      user = insert(:user)
+      follower = insert(:user)
+
+      {:ok, %User{following: following} = follower} = User.follow(follower, user)
+      assert length(following) == 2
+
+      {:ok, follower} =
+        follower
+        |> User.update_changeset(%{following: following ++ following})
+        |> Repo.update()
+
+      assert length(follower.following) == 4
+
+      {:ok, follower} = User.remove_duplicated_following(follower)
+      assert length(follower.following) == 2
+    end
+
+    test "it does nothing when following is uniq" do
+      user = insert(:user)
+      follower = insert(:user)
+
+      {:ok, follower} = User.follow(follower, user)
+      assert length(follower.following) == 2
+
+      {:ok, follower} = User.remove_duplicated_following(follower)
+      assert length(follower.following) == 2
+    end
+  end
+
   describe "follow_import" do
     test "it imports user followings from list" do
       [user1, user2, user3] = insert_list(3, :user)