From d6b0fce6e944e8a3dd05091ef2388c610362f824 Mon Sep 17 00:00:00 2001
From: Alexander Strizhakov <alex.strizhakov@gmail.com>
Date: Tue, 9 Jul 2019 17:36:35 +0000
Subject: [PATCH] Fix/1019 correct count remote users

---
 CHANGELOG.md                                  |   1 +
 config/config.exs                             |   9 +-
 docs/config.md                                |   6 +
 lib/pleroma/application.ex                    |   6 +-
 lib/pleroma/user.ex                           |  66 +++++++++-
 lib/pleroma/user/query.ex                     |  19 ++-
 lib/pleroma/user/synchronization.ex           |  60 +++++++++
 lib/pleroma/user/synchronization_worker.ex    |  32 +++++
 .../users_mock/masto_closed_followers.json    |   7 ++
 .../users_mock/masto_closed_following.json    |   7 ++
 .../users_mock/pleroma_followers.json         |  20 +++
 .../users_mock/pleroma_following.json         |  20 +++
 test/support/http_request_mock.ex             |  48 +++++++
 test/user/synchronization_test.exs            | 104 ++++++++++++++++
 test/user/synchronization_worker_test.exs     |  49 ++++++++
 test/user_test.exs                            | 117 ++++++++++++++++++
 16 files changed, 564 insertions(+), 7 deletions(-)
 create mode 100644 lib/pleroma/user/synchronization.ex
 create mode 100644 lib/pleroma/user/synchronization_worker.ex
 create mode 100644 test/fixtures/users_mock/masto_closed_followers.json
 create mode 100644 test/fixtures/users_mock/masto_closed_following.json
 create mode 100644 test/fixtures/users_mock/pleroma_followers.json
 create mode 100644 test/fixtures/users_mock/pleroma_following.json
 create mode 100644 test/user/synchronization_test.exs
 create mode 100644 test/user/synchronization_worker_test.exs

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 75fa50e00..2d59639bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ Configuration: `federation_incoming_replies_max_depth` option
 - Admin API: Return users' tags when querying reports
 - Admin API: Return avatar and display name when querying users
 - Mastodon API, streaming: Add support for passing the token in the `Sec-WebSocket-Protocol` header
+- Added synchronization of following/followers counters for external users
 
 ### Fixed
 - Not being able to pin unlisted posts
diff --git a/config/config.exs b/config/config.exs
index 675fbb551..09681f122 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -249,7 +249,14 @@
   remote_post_retention_days: 90,
   skip_thread_containment: true,
   limit_to_local_content: :unauthenticated,
-  dynamic_configuration: false
+  dynamic_configuration: false,
+  external_user_synchronization: [
+    enabled: false,
+    # every 2 hours
+    interval: 60 * 60 * 2,
+    max_retries: 3,
+    limit: 500
+  ]
 
 config :pleroma, :markup,
   # XXX - unfortunately, inline images must be enabled by default right now, because
diff --git a/docs/config.md b/docs/config.md
index 822c34c51..931155fe9 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -125,6 +125,12 @@ config :pleroma, Pleroma.Emails.Mailer,
 * `skip_thread_containment`: Skip filter out broken threads. The default is `false`.
 * `limit_to_local_content`: Limit unauthenticated users to search for local statutes and users only. Possible values: `:unauthenticated`, `:all` and `false`. The default is `:unauthenticated`.
 * `dynamic_configuration`: Allow transferring configuration to DB with the subsequent customization from Admin api.
+* `external_user_synchronization`: Following/followers counters synchronization settings.
+  * `enabled`: Enables synchronization
+  * `interval`: Interval between synchronization.
+  * `max_retries`: Max rettries for host. After exceeding the limit, the check will not be carried out for users from this host.
+  * `limit`: Users batch size for processing in one time.
+
 
 
 ## :logger
diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index ba4cf8486..86c348a0d 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -151,7 +151,11 @@ def start(_type, _args) do
             start: {Pleroma.Web.Endpoint, :start_link, []},
             type: :supervisor
           },
-          %{id: Pleroma.Gopher.Server, start: {Pleroma.Gopher.Server, :start_link, []}}
+          %{id: Pleroma.Gopher.Server, start: {Pleroma.Gopher.Server, :start_link, []}},
+          %{
+            id: Pleroma.User.SynchronizationWorker,
+            start: {Pleroma.User.SynchronizationWorker, :start_link, []}
+          }
         ]
 
     # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 09f86aaa2..d03810d1a 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -107,15 +107,25 @@ def ap_id(%User{nickname: nickname}) do
   def ap_followers(%User{follower_address: fa}) when is_binary(fa), do: fa
   def ap_followers(%User{} = user), do: "#{ap_id(user)}/followers"
 
-  def user_info(%User{} = user) do
+  def user_info(%User{} = user, args \\ %{}) do
+    following_count =
+      if args[:following_count], do: args[:following_count], else: following_count(user)
+
+    follower_count =
+      if args[:follower_count], do: args[:follower_count], else: user.info.follower_count
+
     %{
-      following_count: following_count(user),
       note_count: user.info.note_count,
-      follower_count: user.info.follower_count,
       locked: user.info.locked,
       confirmation_pending: user.info.confirmation_pending,
       default_scope: user.info.default_scope
     }
+    |> Map.put(:following_count, following_count)
+    |> Map.put(:follower_count, follower_count)
+  end
+
+  def set_info_cache(user, args) do
+    Cachex.put(:user_cache, "user_info:#{user.id}", user_info(user, args))
   end
 
   def restrict_deactivated(query) do
@@ -1000,6 +1010,56 @@ def perform(:follow_import, %User{} = follower, followed_identifiers)
     )
   end
 
+  @spec sync_follow_counter() :: :ok
+  def sync_follow_counter,
+    do: PleromaJobQueue.enqueue(:background, __MODULE__, [:sync_follow_counters])
+
+  @spec perform(:sync_follow_counters) :: :ok
+  def perform(:sync_follow_counters) do
+    {:ok, _pid} = Agent.start_link(fn -> %{} end, name: :domain_errors)
+    config = Pleroma.Config.get([:instance, :external_user_synchronization])
+
+    :ok = sync_follow_counters(config)
+    Agent.stop(:domain_errors)
+  end
+
+  @spec sync_follow_counters(keyword()) :: :ok
+  def sync_follow_counters(opts \\ []) do
+    users = external_users(opts)
+
+    if length(users) > 0 do
+      errors = Agent.get(:domain_errors, fn state -> state end)
+      {last, updated_errors} = User.Synchronization.call(users, errors, opts)
+      Agent.update(:domain_errors, fn _state -> updated_errors end)
+      sync_follow_counters(max_id: last.id, limit: opts[:limit])
+    else
+      :ok
+    end
+  end
+
+  @spec external_users(keyword()) :: [User.t()]
+  def external_users(opts \\ []) do
+    query =
+      User.Query.build(%{
+        external: true,
+        active: true,
+        order_by: :id,
+        select: [:id, :ap_id, :info]
+      })
+
+    query =
+      if opts[:max_id],
+        do: where(query, [u], u.id > ^opts[:max_id]),
+        else: query
+
+    query =
+      if opts[:limit],
+        do: limit(query, ^opts[:limit]),
+        else: query
+
+    Repo.all(query)
+  end
+
   def blocks_import(%User{} = blocker, blocked_identifiers) when is_list(blocked_identifiers),
     do:
       PleromaJobQueue.enqueue(:background, __MODULE__, [
diff --git a/lib/pleroma/user/query.ex b/lib/pleroma/user/query.ex
index ace9c05f2..f9bcc9e19 100644
--- a/lib/pleroma/user/query.ex
+++ b/lib/pleroma/user/query.ex
@@ -7,7 +7,7 @@ defmodule Pleroma.User.Query do
   User query builder module. Builds query from new query or another user query.
 
     ## Example:
-        query = Pleroma.User.Query(%{nickname: "nickname"})
+        query = Pleroma.User.Query.build(%{nickname: "nickname"})
         another_query = Pleroma.User.Query.build(query, %{email: "email@example.com"})
         Pleroma.Repo.all(query)
         Pleroma.Repo.all(another_query)
@@ -47,7 +47,10 @@ defmodule Pleroma.User.Query do
             friends: User.t(),
             recipients_from_activity: [String.t()],
             nickname: [String.t()],
-            ap_id: [String.t()]
+            ap_id: [String.t()],
+            order_by: term(),
+            select: term(),
+            limit: pos_integer()
           }
           | %{}
 
@@ -141,6 +144,18 @@ defp compose_query({:recipients_from_activity, to}, query) do
     where(query, [u], u.ap_id in ^to or fragment("? && ?", u.following, ^to))
   end
 
+  defp compose_query({:order_by, key}, query) do
+    order_by(query, [u], field(u, ^key))
+  end
+
+  defp compose_query({:select, keys}, query) do
+    select(query, [u], ^keys)
+  end
+
+  defp compose_query({:limit, limit}, query) do
+    limit(query, ^limit)
+  end
+
   defp compose_query(_unsupported_param, query), do: query
 
   defp prepare_tag_criteria(tag, query) do
diff --git a/lib/pleroma/user/synchronization.ex b/lib/pleroma/user/synchronization.ex
new file mode 100644
index 000000000..93660e08c
--- /dev/null
+++ b/lib/pleroma/user/synchronization.ex
@@ -0,0 +1,60 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.User.Synchronization do
+  alias Pleroma.HTTP
+  alias Pleroma.User
+
+  @spec call([User.t()], map(), keyword()) :: {User.t(), map()}
+  def call(users, errors, opts \\ []) do
+    do_call(users, errors, opts)
+  end
+
+  defp do_call([user | []], errors, opts) do
+    updated = fetch_counters(user, errors, opts)
+    {user, updated}
+  end
+
+  defp do_call([user | others], errors, opts) do
+    updated = fetch_counters(user, errors, opts)
+    do_call(others, updated, opts)
+  end
+
+  defp fetch_counters(user, errors, opts) do
+    %{host: host} = URI.parse(user.ap_id)
+
+    info = %{}
+    {following, errors} = fetch_counter(user.ap_id <> "/following", host, errors, opts)
+    info = if following, do: Map.put(info, :following_count, following), else: info
+
+    {followers, errors} = fetch_counter(user.ap_id <> "/followers", host, errors, opts)
+    info = if followers, do: Map.put(info, :follower_count, followers), else: info
+
+    User.set_info_cache(user, info)
+    errors
+  end
+
+  defp available_domain?(domain, errors, opts) do
+    max_retries = Keyword.get(opts, :max_retries, 3)
+    not (Map.has_key?(errors, domain) && errors[domain] >= max_retries)
+  end
+
+  defp fetch_counter(url, host, errors, opts) do
+    with true <- available_domain?(host, errors, opts),
+         {:ok, %{body: body, status: code}} when code in 200..299 <-
+           HTTP.get(
+             url,
+             [{:Accept, "application/activity+json"}]
+           ),
+         {:ok, data} <- Jason.decode(body) do
+      {data["totalItems"], errors}
+    else
+      false ->
+        {nil, errors}
+
+      _ ->
+        {nil, Map.update(errors, host, 1, &(&1 + 1))}
+    end
+  end
+end
diff --git a/lib/pleroma/user/synchronization_worker.ex b/lib/pleroma/user/synchronization_worker.ex
new file mode 100644
index 000000000..ba9cc3556
--- /dev/null
+++ b/lib/pleroma/user/synchronization_worker.ex
@@ -0,0 +1,32 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-onl
+
+defmodule Pleroma.User.SynchronizationWorker do
+  use GenServer
+
+  def start_link do
+    config = Pleroma.Config.get([:instance, :external_user_synchronization])
+
+    if config[:enabled] do
+      GenServer.start_link(__MODULE__, interval: config[:interval])
+    else
+      :ignore
+    end
+  end
+
+  def init(opts) do
+    schedule_next(opts)
+    {:ok, opts}
+  end
+
+  def handle_info(:sync_follow_counters, opts) do
+    Pleroma.User.sync_follow_counter()
+    schedule_next(opts)
+    {:noreply, opts}
+  end
+
+  defp schedule_next(opts) do
+    Process.send_after(self(), :sync_follow_counters, opts[:interval])
+  end
+end
diff --git a/test/fixtures/users_mock/masto_closed_followers.json b/test/fixtures/users_mock/masto_closed_followers.json
new file mode 100644
index 000000000..da296892d
--- /dev/null
+++ b/test/fixtures/users_mock/masto_closed_followers.json
@@ -0,0 +1,7 @@
+{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "id": "http://localhost:4001/users/masto_closed/followers",
+  "type": "OrderedCollection",
+  "totalItems": 437,
+  "first": "http://localhost:4001/users/masto_closed/followers?page=1"
+}
diff --git a/test/fixtures/users_mock/masto_closed_following.json b/test/fixtures/users_mock/masto_closed_following.json
new file mode 100644
index 000000000..146d49f9c
--- /dev/null
+++ b/test/fixtures/users_mock/masto_closed_following.json
@@ -0,0 +1,7 @@
+{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "id": "http://localhost:4001/users/masto_closed/following",
+  "type": "OrderedCollection",
+  "totalItems": 152,
+  "first": "http://localhost:4001/users/masto_closed/following?page=1"
+}
diff --git a/test/fixtures/users_mock/pleroma_followers.json b/test/fixtures/users_mock/pleroma_followers.json
new file mode 100644
index 000000000..db71d084b
--- /dev/null
+++ b/test/fixtures/users_mock/pleroma_followers.json
@@ -0,0 +1,20 @@
+{
+  "type": "OrderedCollection",
+  "totalItems": 527,
+  "id": "http://localhost:4001/users/fuser2/followers",
+  "first": {
+    "type": "OrderedCollectionPage",
+    "totalItems": 527,
+    "partOf": "http://localhost:4001/users/fuser2/followers",
+    "orderedItems": [],
+    "next": "http://localhost:4001/users/fuser2/followers?page=2",
+    "id": "http://localhost:4001/users/fuser2/followers?page=1"
+  },
+  "@context": [
+    "https://www.w3.org/ns/activitystreams",
+    "http://localhost:4001/schemas/litepub-0.1.jsonld",
+    {
+      "@language": "und"
+    }
+  ]
+}
diff --git a/test/fixtures/users_mock/pleroma_following.json b/test/fixtures/users_mock/pleroma_following.json
new file mode 100644
index 000000000..33d087703
--- /dev/null
+++ b/test/fixtures/users_mock/pleroma_following.json
@@ -0,0 +1,20 @@
+{
+  "type": "OrderedCollection",
+  "totalItems": 267,
+  "id": "http://localhost:4001/users/fuser2/following",
+  "first": {
+    "type": "OrderedCollectionPage",
+    "totalItems": 267,
+    "partOf": "http://localhost:4001/users/fuser2/following",
+    "orderedItems": [],
+    "next": "http://localhost:4001/users/fuser2/following?page=2",
+    "id": "http://localhost:4001/users/fuser2/following?page=1"
+  },
+  "@context": [
+    "https://www.w3.org/ns/activitystreams",
+    "http://localhost:4001/schemas/litepub-0.1.jsonld",
+    {
+      "@language": "und"
+    }
+  ]
+}
diff --git a/test/support/http_request_mock.ex b/test/support/http_request_mock.ex
index e6f357412..c593a5e4a 100644
--- a/test/support/http_request_mock.ex
+++ b/test/support/http_request_mock.ex
@@ -759,6 +759,54 @@ def get("https://pleroma.local/notice/9kCP7V", _, _, _) do
     {:ok, %Tesla.Env{status: 200, body: File.read!("test/fixtures/rich_media/ogp.html")}}
   end
 
+  def get("http://localhost:4001/users/masto_closed/followers", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 200,
+       body: File.read!("test/fixtures/users_mock/masto_closed_followers.json")
+     }}
+  end
+
+  def get("http://localhost:4001/users/masto_closed/following", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 200,
+       body: File.read!("test/fixtures/users_mock/masto_closed_following.json")
+     }}
+  end
+
+  def get("http://localhost:4001/users/fuser2/followers", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 200,
+       body: File.read!("test/fixtures/users_mock/pleroma_followers.json")
+     }}
+  end
+
+  def get("http://localhost:4001/users/fuser2/following", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 200,
+       body: File.read!("test/fixtures/users_mock/pleroma_following.json")
+     }}
+  end
+
+  def get("http://domain-with-errors:4001/users/fuser1/followers", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 504,
+       body: ""
+     }}
+  end
+
+  def get("http://domain-with-errors:4001/users/fuser1/following", _, _, _) do
+    {:ok,
+     %Tesla.Env{
+       status: 504,
+       body: ""
+     }}
+  end
+
   def get("http://example.com/ogp-missing-data", _, _, _) do
     {:ok,
      %Tesla.Env{
diff --git a/test/user/synchronization_test.exs b/test/user/synchronization_test.exs
new file mode 100644
index 000000000..67b669431
--- /dev/null
+++ b/test/user/synchronization_test.exs
@@ -0,0 +1,104 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.User.SynchronizationTest do
+  use Pleroma.DataCase
+  import Pleroma.Factory
+  alias Pleroma.User
+  alias Pleroma.User.Synchronization
+
+  setup do
+    Tesla.Mock.mock(fn env -> apply(HttpRequestMock, :request, [env]) end)
+    :ok
+  end
+
+  test "update following/followers counters" do
+    user1 =
+      insert(:user,
+        local: false,
+        ap_id: "http://localhost:4001/users/masto_closed"
+      )
+
+    user2 = insert(:user, local: false, ap_id: "http://localhost:4001/users/fuser2")
+
+    users = User.external_users()
+    assert length(users) == 2
+    {user, %{}} = Synchronization.call(users, %{})
+    assert user == List.last(users)
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user1)
+    assert followers == 437
+    assert following == 152
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user2)
+
+    assert followers == 527
+    assert following == 267
+  end
+
+  test "don't check host if errors exist" do
+    user1 = insert(:user, local: false, ap_id: "http://domain-with-errors:4001/users/fuser1")
+
+    user2 = insert(:user, local: false, ap_id: "http://domain-with-errors:4001/users/fuser2")
+
+    users = User.external_users()
+    assert length(users) == 2
+
+    {user, %{"domain-with-errors" => 2}} =
+      Synchronization.call(users, %{"domain-with-errors" => 2}, max_retries: 2)
+
+    assert user == List.last(users)
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user1)
+    assert followers == 0
+    assert following == 0
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user2)
+
+    assert followers == 0
+    assert following == 0
+  end
+
+  test "don't check host if errors appeared" do
+    user1 = insert(:user, local: false, ap_id: "http://domain-with-errors:4001/users/fuser1")
+
+    user2 = insert(:user, local: false, ap_id: "http://domain-with-errors:4001/users/fuser2")
+
+    users = User.external_users()
+    assert length(users) == 2
+
+    {user, %{"domain-with-errors" => 2}} = Synchronization.call(users, %{}, max_retries: 2)
+
+    assert user == List.last(users)
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user1)
+    assert followers == 0
+    assert following == 0
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user2)
+
+    assert followers == 0
+    assert following == 0
+  end
+
+  test "other users after error appeared" do
+    user1 = insert(:user, local: false, ap_id: "http://domain-with-errors:4001/users/fuser1")
+    user2 = insert(:user, local: false, ap_id: "http://localhost:4001/users/fuser2")
+
+    users = User.external_users()
+    assert length(users) == 2
+
+    {user, %{"domain-with-errors" => 2}} = Synchronization.call(users, %{}, max_retries: 2)
+    assert user == List.last(users)
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user1)
+    assert followers == 0
+    assert following == 0
+
+    %{follower_count: followers, following_count: following} = User.get_cached_user_info(user2)
+
+    assert followers == 527
+    assert following == 267
+  end
+end
diff --git a/test/user/synchronization_worker_test.exs b/test/user/synchronization_worker_test.exs
new file mode 100644
index 000000000..835c5327f
--- /dev/null
+++ b/test/user/synchronization_worker_test.exs
@@ -0,0 +1,49 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.User.SynchronizationWorkerTest do
+  use Pleroma.DataCase
+  import Pleroma.Factory
+
+  setup do
+    Tesla.Mock.mock_global(fn env -> apply(HttpRequestMock, :request, [env]) end)
+
+    config = Pleroma.Config.get([:instance, :external_user_synchronization])
+
+    for_update = [enabled: true, interval: 1000]
+
+    Pleroma.Config.put([:instance, :external_user_synchronization], for_update)
+
+    on_exit(fn ->
+      Pleroma.Config.put([:instance, :external_user_synchronization], config)
+    end)
+
+    :ok
+  end
+
+  test "sync follow counters" do
+    user1 =
+      insert(:user,
+        local: false,
+        ap_id: "http://localhost:4001/users/masto_closed"
+      )
+
+    user2 = insert(:user, local: false, ap_id: "http://localhost:4001/users/fuser2")
+
+    {:ok, _} = Pleroma.User.SynchronizationWorker.start_link()
+    :timer.sleep(1500)
+
+    %{follower_count: followers, following_count: following} =
+      Pleroma.User.get_cached_user_info(user1)
+
+    assert followers == 437
+    assert following == 152
+
+    %{follower_count: followers, following_count: following} =
+      Pleroma.User.get_cached_user_info(user2)
+
+    assert followers == 527
+    assert following == 267
+  end
+end
diff --git a/test/user_test.exs b/test/user_test.exs
index fb497843c..0f27d73f7 100644
--- a/test/user_test.exs
+++ b/test/user_test.exs
@@ -1183,4 +1183,121 @@ test "it returns a list of AP ids for a given set of nicknames" do
       assert user_two.ap_id in ap_ids
     end
   end
+
+  describe "sync followers count" do
+    setup do
+      user1 = insert(:user, local: false, ap_id: "http://localhost:4001/users/masto_closed")
+      user2 = insert(:user, local: false, ap_id: "http://localhost:4001/users/fuser2")
+      insert(:user, local: true)
+      insert(:user, local: false, info: %{deactivated: true})
+      {:ok, user1: user1, user2: user2}
+    end
+
+    test "external_users/1 external active users with limit", %{user1: user1, user2: user2} do
+      [fdb_user1] = User.external_users(limit: 1)
+
+      assert fdb_user1.ap_id
+      assert fdb_user1.ap_id == user1.ap_id
+      assert fdb_user1.id == user1.id
+
+      [fdb_user2] = User.external_users(max_id: fdb_user1.id, limit: 1)
+
+      assert fdb_user2.ap_id
+      assert fdb_user2.ap_id == user2.ap_id
+      assert fdb_user2.id == user2.id
+
+      assert User.external_users(max_id: fdb_user2.id, limit: 1) == []
+    end
+
+    test "sync_follow_counters/1", %{user1: user1, user2: user2} do
+      {:ok, _pid} = Agent.start_link(fn -> %{} end, name: :domain_errors)
+
+      :ok = User.sync_follow_counters()
+
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user1)
+      assert followers == 437
+      assert following == 152
+
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user2)
+
+      assert followers == 527
+      assert following == 267
+
+      Agent.stop(:domain_errors)
+    end
+
+    test "sync_follow_counters/1 in separate batches", %{user1: user1, user2: user2} do
+      {:ok, _pid} = Agent.start_link(fn -> %{} end, name: :domain_errors)
+
+      :ok = User.sync_follow_counters(limit: 1)
+
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user1)
+      assert followers == 437
+      assert following == 152
+
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user2)
+
+      assert followers == 527
+      assert following == 267
+
+      Agent.stop(:domain_errors)
+    end
+
+    test "perform/1 with :sync_follow_counters", %{user1: user1, user2: user2} do
+      :ok = User.perform(:sync_follow_counters)
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user1)
+      assert followers == 437
+      assert following == 152
+
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user2)
+
+      assert followers == 527
+      assert following == 267
+    end
+  end
+
+  describe "set_info_cache/2" do
+    setup do
+      user = insert(:user)
+      {:ok, user: user}
+    end
+
+    test "update from args", %{user: user} do
+      User.set_info_cache(user, %{following_count: 15, follower_count: 18})
+
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user)
+      assert followers == 18
+      assert following == 15
+    end
+
+    test "without args", %{user: user} do
+      User.set_info_cache(user, %{})
+
+      %{follower_count: followers, following_count: following} = User.get_cached_user_info(user)
+      assert followers == 0
+      assert following == 0
+    end
+  end
+
+  describe "user_info/2" do
+    setup do
+      user = insert(:user)
+      {:ok, user: user}
+    end
+
+    test "update from args", %{user: user} do
+      %{follower_count: followers, following_count: following} =
+        User.user_info(user, %{following_count: 15, follower_count: 18})
+
+      assert followers == 18
+      assert following == 15
+    end
+
+    test "without args", %{user: user} do
+      %{follower_count: followers, following_count: following} = User.user_info(user)
+
+      assert followers == 0
+      assert following == 0
+    end
+  end
 end