Add activity expirations table

Add a table to store activity expirations. An activity can have zero or
one expirations. The expiration has a scheduled_at field which stores
the time at which the activity should expire and be deleted.

test/activity_expiration_test.exs

@@ -0,0 +1,21 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.ActivityExpirationTest do
+  use Pleroma.DataCase
+  alias Pleroma.ActivityExpiration
+  import Pleroma.Factory
+
+  test "finds activities due to be deleted only" do
+    activity = insert(:note_activity)
+    expiration_due = insert(:expiration_in_the_past, %{activity_id: activity.id})
+    activity2 = insert(:note_activity)
+    insert(:expiration_in_the_future, %{activity_id: activity2.id})
+
+    expirations = ActivityExpiration.due_expirations()
+
+    assert length(expirations) == 1
+    assert hd(expirations) == expiration_due
+  end
+end

test/activity_test.exs

@@ -164,4 +164,13 @@ defmodule Pleroma.ActivityTest do
       Pleroma.Config.put([:instance, :limit_to_local_content], :unauthenticated)
     end
   end
+
+  test "add an activity with an expiration" do
+    activity = insert(:note_activity)
+    insert(:expiration_in_the_future, %{activity_id: activity.id})
+
+    Pleroma.ActivityExpiration
+    |> where([a], a.activity_id == ^activity.id)
+    |> Repo.one!()
+  end
 end

test/support/factory.ex

@@ -1,5 +1,5 @@
 # Pleroma: A lightweight social networking server
-# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Factory do
@@ -142,6 +142,23 @@ defmodule Pleroma.Factory do
     |> Map.merge(attrs)
   end
 
+  defp expiration_offset_by_minutes(attrs, minutes) do
+    %Pleroma.ActivityExpiration{}
+    |> Map.merge(attrs)
+    |> Map.put(
+      :scheduled_at,
+      NaiveDateTime.add(NaiveDateTime.utc_now(), :timer.minutes(minutes), :millisecond)
+    )
+  end
+
+  def expiration_in_the_past_factory(attrs \\ %{}) do
+    expiration_offset_by_minutes(attrs, -60)
+  end
+
+  def expiration_in_the_future_factory(attrs \\ %{}) do
+    expiration_offset_by_minutes(attrs, 60)
+  end
+
   def article_activity_factory do
     article = insert(:article)