added notification constraints

lib/pleroma/migration_helper/notification_backfill.ex

@@ -19,13 +19,13 @@ defmodule Pleroma.MigrationHelper.NotificationBackfill do
     query
     |> Repo.chunk_stream(100)
     |> Enum.each(fn notification ->
-      type =
-        notification.activity
-        |> type_from_activity()
+      if notification.activity do
+        type = type_from_activity(notification.activity)
 
-      notification
-      |> Ecto.Changeset.change(%{type: type})
-      |> Repo.update()
+        notification
+        |> Ecto.Changeset.change(%{type: type})
+        |> Repo.update()
+      end
     end)
   end
 
@@ -72,8 +72,7 @@ defmodule Pleroma.MigrationHelper.NotificationBackfill do
         "pleroma:emoji_reaction"
 
       "Create" ->
-        activity
-        |> type_from_activity_object()
+        type_from_activity_object(activity)
 
       t ->
         raise "No notification type for activity type #{t}"

lib/pleroma/repo.ex

@@ -49,7 +49,7 @@ defmodule Pleroma.Repo do
     end
   end
 
-  def chunk_stream(query, chunk_size) do
+  def chunk_stream(query, chunk_size, returns_as \\ :one) do
     # We don't actually need start and end funcitons of resource streaming,
     # but it seems to be the only way to not fetch records one-by-one and
     # have individual records be the elements of the stream, instead of
@@ -69,7 +69,12 @@ defmodule Pleroma.Repo do
 
             records ->
               last_id = List.last(records).id
-              {records, last_id}
+
+              if returns_as == :one do
+                {records, last_id}
+              else
+                {[records], last_id}
+              end
           end
       end,
       fn _ -> :ok end