Pipeline: Add a side effects step after the transaction finishes

This is to run things like streaming notifications out, which will
sometimes need data that is created by the transaction, but is
streamed out asynchronously.

lib/pleroma/notification.ex

@@ -334,30 +334,34 @@ def dismiss(%{id: user_id} = _user, id) do
     end
   end
 
-  def create_notifications(%Activity{data: %{"to" => _, "type" => "Create"}} = activity) do
+  def create_notifications(activity, options \\ [])
+
+  def create_notifications(%Activity{data: %{"to" => _, "type" => "Create"}} = activity, options) do
     object = Object.normalize(activity, false)
 
     if object && object.data["type"] == "Answer" do
       {:ok, []}
     else
-      do_create_notifications(activity)
+      do_create_notifications(activity, options)
     end
   end
 
-  def create_notifications(%Activity{data: %{"type" => type}} = activity)
+  def create_notifications(%Activity{data: %{"type" => type}} = activity, options)
       when type in ["Follow", "Like", "Announce", "Move", "EmojiReact"] do
-    do_create_notifications(activity)
+    do_create_notifications(activity, options)
   end
 
-  def create_notifications(_), do: {:ok, []}
+  def create_notifications(_, _), do: {:ok, []}
+
+  defp do_create_notifications(%Activity{} = activity, options) do
+    do_send = Keyword.get(options, :do_send, true)
 
-  defp do_create_notifications(%Activity{} = activity) do
     {enabled_receivers, disabled_receivers} = get_notified_from_activity(activity)
     potential_receivers = enabled_receivers ++ disabled_receivers
 
     notifications =
       Enum.map(potential_receivers, fn user ->
-        do_send = user in enabled_receivers
+        do_send = do_send && user in enabled_receivers
         create_notification(activity, user, do_send)
       end)
 
@@ -623,4 +627,12 @@ def skip?(:recently_followed, %Activity{data: %{"type" => "Follow"}} = activity,
   end
 
   def skip?(_, _, _), do: false
+
+  def for_user_and_activity(user, activity) do
+    from(n in __MODULE__,
+      where: n.user_id == ^user.id,
+      where: n.activity_id == ^activity.id
+    )
+    |> Repo.one()
+  end
 end

lib/pleroma/web/activity_pub/pipeline.ex

@@ -17,6 +17,10 @@ defmodule Pleroma.Web.ActivityPub.Pipeline do
           {:ok, Activity.t() | Object.t(), keyword()} | {:error, any()}
   def common_pipeline(object, meta) do
     case Repo.transaction(fn -> do_common_pipeline(object, meta) end) do
+      {:ok, {:ok, activity, meta}} ->
+        SideEffects.handle_after_transaction(meta)
+        {:ok, activity, meta}
+
       {:ok, value} ->
         value
 

lib/pleroma/web/activity_pub/side_effects.ex

@@ -16,6 +16,7 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
   alias Pleroma.Web.ActivityPub.Pipeline
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.Streamer
+  alias Pleroma.Web.Push
 
   def handle(object, meta \\ [])
 
@@ -37,7 +38,12 @@ def handle(%{data: %{"type" => "Like"}} = object, meta) do
   # - Set up notifications
   def handle(%{data: %{"type" => "Create"}} = activity, meta) do
     with {:ok, _object, _meta} <- handle_object_creation(meta[:object_data], meta) do
-      Notification.create_notifications(activity)
+      {:ok, notifications} = Notification.create_notifications(activity, do_send: false)
+
+      meta =
+        meta
+        |> add_notifications(notifications)
+
       {:ok, activity, meta}
     else
       e -> Repo.rollback(e)
@@ -200,4 +206,26 @@ def handle_undoing(
   end
 
   def handle_undoing(object), do: {:error, ["don't know how to handle", object]}
+
+  defp send_notifications(meta) do
+    Keyword.get(meta, :created_notifications, [])
+    |> Enum.each(fn notification ->
+      Streamer.stream(["user", "user:notification"], notification)
+      Push.send(notification)
+    end)
+
+    meta
+  end
+
+  defp add_notifications(meta, notifications) do
+    existing = Keyword.get(meta, :created_notifications, [])
+
+    meta
+    |> Keyword.put(:created_notifications, notifications ++ existing)
+  end
+
+  def handle_after_transaction(meta) do
+    meta
+    |> send_notifications()
+  end
 end

test/web/activity_pub/pipeline_test.exs

@@ -33,7 +33,10 @@ test "it goes through validation, filtering, persisting, side effects and federa
         {
           Pleroma.Web.ActivityPub.SideEffects,
           [],
-          [handle: fn o, m -> {:ok, o, m} end]
+          [
+            handle: fn o, m -> {:ok, o, m} end,
+            handle_after_transaction: fn m -> m end
+          ]
         },
         {
           Pleroma.Web.Federator,
@@ -71,7 +74,7 @@ test "it goes through validation, filtering, persisting, side effects without fe
         {
           Pleroma.Web.ActivityPub.SideEffects,
           [],
-          [handle: fn o, m -> {:ok, o, m} end]
+          [handle: fn o, m -> {:ok, o, m} end, handle_after_transaction: fn m -> m end]
         },
         {
           Pleroma.Web.Federator,
@@ -110,7 +113,7 @@ test "it goes through validation, filtering, persisting, side effects without fe
         {
           Pleroma.Web.ActivityPub.SideEffects,
           [],
-          [handle: fn o, m -> {:ok, o, m} end]
+          [handle: fn o, m -> {:ok, o, m} end, handle_after_transaction: fn m -> m end]
         },
         {
           Pleroma.Web.Federator,

test/web/activity_pub/side_effects_test.exs

@@ -22,6 +22,47 @@ defmodule Pleroma.Web.ActivityPub.SideEffectsTest do
   import Pleroma.Factory
   import Mock
 
+  describe "handle_after_transaction" do
+    test "it streams out notifications" do
+      author = insert(:user, local: true)
+      recipient = insert(:user, local: true)
+
+      {:ok, chat_message_data, _meta} = Builder.chat_message(author, recipient.ap_id, "hey")
+
+      {:ok, create_activity_data, _meta} =
+        Builder.create(author, chat_message_data["id"], [recipient.ap_id])
+
+      {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
+
+      {:ok, _create_activity, meta} =
+        SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
+
+      assert [notification] = meta[:created_notifications]
+
+      with_mocks([
+        {
+          Pleroma.Web.Streamer,
+          [],
+          [
+            stream: fn _, _ -> nil end
+          ]
+        },
+        {
+          Pleroma.Web.Push,
+          [],
+          [
+            send: fn _ -> nil end
+          ]
+        }
+      ]) do
+        SideEffects.handle_after_transaction(meta)
+
+        assert called(Pleroma.Web.Streamer.stream(["user", "user:notification"], notification))
+        assert called(Pleroma.Web.Push.send(notification))
+      end
+    end
+  end
+
   describe "delete objects" do
     setup do
       user = insert(:user)
@@ -361,9 +402,33 @@ test "it creates a Chat and ChatMessageReferences for the local users and bumps
 
       {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
 
-      {:ok, _create_activity, _meta} =
+      with_mocks([
+        {
+          Pleroma.Web.Streamer,
+          [],
+          [
+            stream: fn _, _ -> nil end
+          ]
+        },
+        {
+          Pleroma.Web.Push,
+          [],
+          [
+            send: fn _ -> nil end
+          ]
+        }
+      ]) do
+        {:ok, _create_activity, meta} =
           SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
 
+        # The notification gets created
+        assert [notification] = meta[:created_notifications]
+        assert notification.activity_id == create_activity.id
+
+        # But it is not sent out
+        refute called(Pleroma.Web.Streamer.stream(["user", "user:notification"], notification))
+        refute called(Pleroma.Web.Push.send(notification))
+
         chat = Chat.get(author.id, recipient.ap_id)
 
         [cm_ref] = ChatMessageReference.for_chat_query(chat) |> Repo.all()
@@ -378,6 +443,7 @@ test "it creates a Chat and ChatMessageReferences for the local users and bumps
         assert cm_ref.object.data["content"] == "hey"
         assert cm_ref.unread == true
       end
+    end
 
     test "it creates a Chat for the local users and bumps the unread count" do
       author = insert(:user, local: false)

test/web/common_api/common_api_test.exs

@@ -7,6 +7,7 @@ defmodule Pleroma.Web.CommonAPITest do
   alias Pleroma.Activity
   alias Pleroma.Chat
   alias Pleroma.Conversation.Participation
+  alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.ActivityPub
@@ -39,6 +40,24 @@ test "it posts a chat message without content but with an attachment" do
 
       {:ok, upload} = ActivityPub.upload(file, actor: author.ap_id)
 
+      with_mocks([
+        {
+          Pleroma.Web.Streamer,
+          [],
+          [
+            stream: fn _, _ ->
+              nil
+            end
+          ]
+        },
+        {
+          Pleroma.Web.Push,
+          [],
+          [
+            send: fn _ -> nil end
+          ]
+        }
+      ]) do
         {:ok, activity} =
           CommonAPI.post_chat_message(
             author,
@@ -47,8 +66,16 @@ test "it posts a chat message without content but with an attachment" do
             media_id: upload.id
           )
 
+        notification =
+          Notification.for_user_and_activity(recipient, activity)
+          |> Repo.preload(:activity)
+
+        assert called(Pleroma.Web.Push.send(notification))
+        assert called(Pleroma.Web.Streamer.stream(["user", "user:notification"], notification))
+
         assert activity
       end
+    end
 
     test "it adds html newlines" do
       author = insert(:user)