Merge branch 'feature/delete-validator' into 'develop'

Move deletions to the common pipeline

Closes #1497

See merge request pleroma/pleroma!2441

lib/mix/tasks/pleroma/user.ex

@@ -8,6 +8,8 @@ defmodule Mix.Tasks.Pleroma.User do
   alias Ecto.Changeset
   alias Pleroma.User
   alias Pleroma.UserInviteToken
+  alias Pleroma.Web.ActivityPub.Builder
+  alias Pleroma.Web.ActivityPub.Pipeline
 
   @shortdoc "Manages Pleroma users"
   @moduledoc File.read!("docs/administration/CLI_tasks/user.md")
@@ -96,8 +98,9 @@ def run(["new", nickname, email | rest]) do
   def run(["rm", nickname]) do
     start_pleroma()
 
-    with %User{local: true} = user <- User.get_cached_by_nickname(nickname) do
-      User.perform(:delete, user)
+    with %User{local: true} = user <- User.get_cached_by_nickname(nickname),
+         {:ok, delete_data, _} <- Builder.delete(user, user.ap_id),
+         {:ok, _delete, _} <- Pipeline.common_pipeline(delete_data, local: true) do
       shell_info("User #{nickname} deleted.")
     else
       _ -> shell_error("No local user #{nickname}")

lib/pleroma/user.ex

@@ -29,7 +29,9 @@ defmodule Pleroma.User do
   alias Pleroma.UserRelationship
   alias Pleroma.Web
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Builder
   alias Pleroma.Web.ActivityPub.ObjectValidators.Types
+  alias Pleroma.Web.ActivityPub.Pipeline
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.CommonAPI
   alias Pleroma.Web.CommonAPI.Utils, as: CommonUtils
@@ -1425,8 +1427,6 @@ def perform(:force_password_reset, user), do: force_password_reset(user)
 
   @spec perform(atom(), User.t()) :: {:ok, User.t()}
   def perform(:delete, %User{} = user) do
-    {:ok, _user} = ActivityPub.delete(user)
-
     # Remove all relationships
     user
     |> get_followers()
@@ -1536,21 +1536,23 @@ def follow_import(%User{} = follower, followed_identifiers)
     })
   end
 
-  def delete_user_activities(%User{ap_id: ap_id}) do
+  def delete_user_activities(%User{ap_id: ap_id} = user) do
     ap_id
     |> Activity.Queries.by_actor()
     |> RepoStreamer.chunk_stream(50)
-    |> Stream.each(fn activities -> Enum.each(activities, &delete_activity/1) end)
+    |> Stream.each(fn activities ->
+      Enum.each(activities, fn activity -> delete_activity(activity, user) end)
+    end)
     |> Stream.run()
   end
 
-  defp delete_activity(%{data: %{"type" => "Create"}} = activity) do
-    activity
-    |> Object.normalize()
-    |> ActivityPub.delete()
+  defp delete_activity(%{data: %{"type" => "Create", "object" => object}}, user) do
+    {:ok, delete_data, _} = Builder.delete(user, object)
+
+    Pipeline.common_pipeline(delete_data, local: true)
   end
 
-  defp delete_activity(%{data: %{"type" => "Like"}} = activity) do
+  defp delete_activity(%{data: %{"type" => "Like"}} = activity, _user) do
     object = Object.normalize(activity)
 
     activity.actor
@@ -1558,7 +1560,7 @@ defp delete_activity(%{data: %{"type" => "Like"}} = activity) do
     |> ActivityPub.unlike(object)
   end
 
-  defp delete_activity(%{data: %{"type" => "Announce"}} = activity) do
+  defp delete_activity(%{data: %{"type" => "Announce"}} = activity, _user) do
     object = Object.normalize(activity)
 
     activity.actor
@@ -1566,7 +1568,7 @@ defp delete_activity(%{data: %{"type" => "Announce"}} = activity) do
     |> ActivityPub.unannounce(object)
   end
 
-  defp delete_activity(_activity), do: "Doing nothing"
+  defp delete_activity(_activity, _user), do: "Doing nothing"
 
   def html_filter_policy(%User{no_rich_text: true}) do
     Pleroma.HTML.Scrubber.TwitterText

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -519,67 +519,6 @@ defp do_unfollow(follower, followed, activity_id, local) do
     end
   end
 
-  @spec delete(User.t() | Object.t(), keyword()) :: {:ok, User.t() | Object.t()} | {:error, any()}
-  def delete(entity, options \\ []) do
-    with {:ok, result} <- Repo.transaction(fn -> do_delete(entity, options) end) do
-      result
-    end
-  end
-
-  defp do_delete(%User{ap_id: ap_id, follower_address: follower_address} = user, _) do
-    with data <- %{
-           "to" => [follower_address],
-           "type" => "Delete",
-           "actor" => ap_id,
-           "object" => %{"type" => "Person", "id" => ap_id}
-         },
-         {:ok, activity} <- insert(data, true, true, true),
-         :ok <- maybe_federate(activity) do
-      {:ok, user}
-    end
-  end
-
-  defp do_delete(%Object{data: %{"id" => id, "actor" => actor}} = object, options) do
-    local = Keyword.get(options, :local, true)
-    activity_id = Keyword.get(options, :activity_id, nil)
-    actor = Keyword.get(options, :actor, actor)
-
-    user = User.get_cached_by_ap_id(actor)
-    to = (object.data["to"] || []) ++ (object.data["cc"] || [])
-
-    with create_activity <- Activity.get_create_by_object_ap_id(id),
-         data <-
-           %{
-             "type" => "Delete",
-             "actor" => actor,
-             "object" => id,
-             "to" => to,
-             "deleted_activity_id" => create_activity && create_activity.id
-           }
-           |> maybe_put("id", activity_id),
-         {:ok, activity} <- insert(data, local, false),
-         {:ok, object, _create_activity} <- Object.delete(object),
-         stream_out_participations(object, user),
-         _ <- decrease_replies_count_if_reply(object),
-         {:ok, _actor} <- decrease_note_count_if_public(user, object),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity}
-    else
-      {:error, error} ->
-        Repo.rollback(error)
-    end
-  end
-
-  defp do_delete(%Object{data: %{"type" => "Tombstone", "id" => ap_id}}, _) do
-    activity =
-      ap_id
-      |> Activity.Queries.by_object_id()
-      |> Activity.Queries.by_type("Delete")
-      |> Repo.one()
-
-    {:ok, activity}
-  end
-
   @spec block(User.t(), User.t(), String.t() | nil, boolean()) ::
           {:ok, Activity.t()} | {:error, any()}
   def block(blocker, blocked, activity_id \\ nil, local \\ true) do

lib/pleroma/web/activity_pub/activity_pub_controller.ex

@@ -415,7 +415,8 @@ defp handle_user_activity(%User{} = user, %{"type" => "Create"} = params) do
   defp handle_user_activity(%User{} = user, %{"type" => "Delete"} = params) do
     with %Object{} = object <- Object.normalize(params["object"]),
          true <- user.is_moderator || user.ap_id == object.data["actor"],
-         {:ok, delete} <- ActivityPub.delete(object) do
+         {:ok, delete_data, _} <- Builder.delete(user, object.data["id"]),
+         {:ok, delete, _} <- Pipeline.common_pipeline(delete_data, local: true) do
       {:ok, delete}
     else
       _ -> {:error, dgettext("errors", "Can't delete object")}

lib/pleroma/web/activity_pub/builder.ex

@@ -10,6 +10,33 @@ defmodule Pleroma.Web.ActivityPub.Builder do
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.ActivityPub.Visibility
 
+  @spec delete(User.t(), String.t()) :: {:ok, map(), keyword()}
+  def delete(actor, object_id) do
+    object = Object.normalize(object_id, false)
+
+    user = !object && User.get_cached_by_ap_id(object_id)
+
+    to =
+      case {object, user} do
+        {%Object{}, _} ->
+          # We are deleting an object, address everyone who was originally mentioned
+          (object.data["to"] || []) ++ (object.data["cc"] || [])
+
+        {_, %User{follower_address: follower_address}} ->
+          # We are deleting a user, address the followers of that user
+          [follower_address]
+      end
+
+    {:ok,
+     %{
+       "id" => Utils.generate_activity_id(),
+       "actor" => actor.ap_id,
+       "object" => object_id,
+       "to" => to,
+       "type" => "Delete"
+     }, []}
+  end
+
   @spec like(User.t(), Object.t()) :: {:ok, map(), keyword()}
   def like(actor, object) do
     object_actor = User.get_cached_by_ap_id(object.data["actor"])

lib/pleroma/web/activity_pub/object_validator.ex

@@ -11,11 +11,23 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
 
   alias Pleroma.Object
   alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ObjectValidators.DeleteValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.LikeValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types
 
   @spec validate(map(), keyword()) :: {:ok, map(), keyword()} | {:error, any()}
   def validate(object, meta)
 
+  def validate(%{"type" => "Delete"} = object, meta) do
+    with cng <- DeleteValidator.cast_and_validate(object),
+         do_not_federate <- DeleteValidator.do_not_federate?(cng),
+         {:ok, object} <- Ecto.Changeset.apply_action(cng, :insert) do
+      object = stringify_keys(object)
+      meta = Keyword.put(meta, :do_not_federate, do_not_federate)
+      {:ok, object, meta}
+    end
+  end
+
   def validate(%{"type" => "Like"} = object, meta) do
     with {:ok, object} <-
            object |> LikeValidator.cast_and_validate() |> Ecto.Changeset.apply_action(:insert) do
@@ -24,13 +36,25 @@ def validate(%{"type" => "Like"} = object, meta) do
     end
   end
 
+  def stringify_keys(%{__struct__: _} = object) do
+    object
+    |> Map.from_struct()
+    |> stringify_keys
+  end
+
   def stringify_keys(object) do
     object
     |> Map.new(fn {key, val} -> {to_string(key), val} end)
   end
 
+  def fetch_actor(object) do
+    with {:ok, actor} <- Types.ObjectID.cast(object["actor"]) do
+      User.get_or_fetch_by_ap_id(actor)
+    end
+  end
+
   def fetch_actor_and_object(object) do
-    User.get_or_fetch_by_ap_id(object["actor"])
+    fetch_actor(object)
     Object.normalize(object["object"])
     :ok
   end

lib/pleroma/web/activity_pub/object_validators/common_validations.ex

@@ -8,7 +8,29 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations do
   alias Pleroma.Object
   alias Pleroma.User
 
-  def validate_actor_presence(cng, field_name \\ :actor) do
+  def validate_recipients_presence(cng, fields \\ [:to, :cc]) do
+    non_empty =
+      fields
+      |> Enum.map(fn field -> get_field(cng, field) end)
+      |> Enum.any?(fn
+        [] -> false
+        _ -> true
+      end)
+
+    if non_empty do
+      cng
+    else
+      fields
+      |> Enum.reduce(cng, fn field, cng ->
+        cng
+        |> add_error(field, "no recipients in any field")
+      end)
+    end
+  end
+
+  def validate_actor_presence(cng, options \\ []) do
+    field_name = Keyword.get(options, :field_name, :actor)
+
     cng
     |> validate_change(field_name, fn field_name, actor ->
       if User.get_cached_by_ap_id(actor) do
@@ -19,14 +41,39 @@ def validate_actor_presence(cng, field_name \\ :actor) do
     end)
   end
 
-  def validate_object_presence(cng, field_name \\ :object) do
+  def validate_object_presence(cng, options \\ []) do
+    field_name = Keyword.get(options, :field_name, :object)
+    allowed_types = Keyword.get(options, :allowed_types, false)
+
     cng
-    |> validate_change(field_name, fn field_name, object ->
-      if Object.get_cached_by_ap_id(object) do
-        []
-      else
+    |> validate_change(field_name, fn field_name, object_id ->
+      object = Object.get_cached_by_ap_id(object_id)
+
+      cond do
+        !object ->
           [{field_name, "can't find object"}]
+
+        object && allowed_types && object.data["type"] not in allowed_types ->
+          [{field_name, "object not in allowed types"}]
+
+        true ->
+          []
       end
     end)
   end
+
+  def validate_object_or_user_presence(cng, options \\ []) do
+    field_name = Keyword.get(options, :field_name, :object)
+    options = Keyword.put(options, :field_name, field_name)
+
+    actor_cng =
+      cng
+      |> validate_actor_presence(options)
+
+    object_cng =
+      cng
+      |> validate_object_presence(options)
+
+    if actor_cng.valid?, do: actor_cng, else: object_cng
+  end
 end

lib/pleroma/web/activity_pub/object_validators/delete_validator.ex

@@ -0,0 +1,99 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.DeleteValidator do
+  use Ecto.Schema
+
+  alias Pleroma.Activity
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types
+
+  import Ecto.Changeset
+  import Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations
+
+  @primary_key false
+
+  embedded_schema do
+    field(:id, Types.ObjectID, primary_key: true)
+    field(:type, :string)
+    field(:actor, Types.ObjectID)
+    field(:to, Types.Recipients, default: [])
+    field(:cc, Types.Recipients, default: [])
+    field(:deleted_activity_id, Types.ObjectID)
+    field(:object, Types.ObjectID)
+  end
+
+  def cast_data(data) do
+    %__MODULE__{}
+    |> cast(data, __schema__(:fields))
+  end
+
+  def add_deleted_activity_id(cng) do
+    object =
+      cng
+      |> get_field(:object)
+
+    with %Activity{id: id} <- Activity.get_create_by_object_ap_id(object) do
+      cng
+      |> put_change(:deleted_activity_id, id)
+    else
+      _ -> cng
+    end
+  end
+
+  @deletable_types ~w{
+    Answer
+    Article
+    Audio
+    Event
+    Note
+    Page
+    Question
+    Video
+  }
+  def validate_data(cng) do
+    cng
+    |> validate_required([:id, :type, :actor, :to, :cc, :object])
+    |> validate_inclusion(:type, ["Delete"])
+    |> validate_actor_presence()
+    |> validate_deletion_rights()
+    |> validate_object_or_user_presence(allowed_types: @deletable_types)
+    |> add_deleted_activity_id()
+  end
+
+  def do_not_federate?(cng) do
+    !same_domain?(cng)
+  end
+
+  defp same_domain?(cng) do
+    actor_uri =
+      cng
+      |> get_field(:actor)
+      |> URI.parse()
+
+    object_uri =
+      cng
+      |> get_field(:object)
+      |> URI.parse()
+
+    object_uri.host == actor_uri.host
+  end
+
+  def validate_deletion_rights(cng) do
+    actor = User.get_cached_by_ap_id(get_field(cng, :actor))
+
+    if User.superuser?(actor) || same_domain?(cng) do
+      cng
+    else
+      cng
+      |> add_error(:actor, "is not allowed to delete object")
+    end
+  end
+
+  def cast_and_validate(data) do
+    data
+    |> cast_data
+    |> validate_data
+  end
+end

lib/pleroma/web/activity_pub/object_validators/like_validator.ex

@@ -20,8 +20,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.LikeValidator do
     field(:object, Types.ObjectID)
     field(:actor, Types.ObjectID)
     field(:context, :string)
-    field(:to, {:array, :string}, default: [])
-    field(:cc, {:array, :string}, default: [])
+    field(:to, Types.Recipients, default: [])
+    field(:cc, Types.Recipients, default: [])
   end
 
   def cast_and_validate(data) do

lib/pleroma/web/activity_pub/object_validators/types/recipients.ex

@@ -0,0 +1,34 @@
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.Types.Recipients do
+  use Ecto.Type
+
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types.ObjectID
+
+  def type, do: {:array, ObjectID}
+
+  def cast(object) when is_binary(object) do
+    cast([object])
+  end
+
+  def cast(data) when is_list(data) do
+    data
+    |> Enum.reduce({:ok, []}, fn element, acc ->
+      case {acc, ObjectID.cast(element)} do
+        {:error, _} -> :error
+        {_, :error} -> :error
+        {{:ok, list}, {:ok, id}} -> {:ok, [id | list]}
+      end
+    end)
+  end
+
+  def cast(_) do
+    :error
+  end
+
+  def dump(data) do
+    {:ok, data}
+  end
+
+  def load(data) do
+    {:ok, data}
+  end
+end

lib/pleroma/web/activity_pub/pipeline.ex

@@ -44,7 +44,9 @@ defp maybe_federate(%Object{}, _), do: {:ok, :not_federated}
 
   defp maybe_federate(%Activity{} = activity, meta) do
     with {:ok, local} <- Keyword.fetch(meta, :local) do
-      if local do
+      do_not_federate = meta[:do_not_federate]
+
+      if !do_not_federate && local do
         Federator.publish(activity)
         {:ok, :federated}
       else

lib/pleroma/web/activity_pub/side_effects.ex

@@ -7,6 +7,8 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
   """
   alias Pleroma.Notification
   alias Pleroma.Object
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Utils
 
   def handle(object, meta \\ [])
@@ -23,6 +25,49 @@ def handle(%{data: %{"type" => "Like"}} = object, meta) do
     {:ok, object, meta}
   end
 
+  # Tasks this handles:
+  # - Delete and unpins the create activity
+  # - Replace object with Tombstone
+  # - Set up notification
+  # - Reduce the user note count
+  # - Reduce the reply count
+  # - Stream out the activity
+  def handle(%{data: %{"type" => "Delete", "object" => deleted_object}} = object, meta) do
+    deleted_object =
+      Object.normalize(deleted_object, false) || User.get_cached_by_ap_id(deleted_object)
+
+    result =
+      case deleted_object do
+        %Object{} ->
+          with {:ok, deleted_object, activity} <- Object.delete(deleted_object),
+               %User{} = user <- User.get_cached_by_ap_id(deleted_object.data["actor"]) do
+            User.remove_pinnned_activity(user, activity)
+
+            {:ok, user} = ActivityPub.decrease_note_count_if_public(user, deleted_object)
+
+            if in_reply_to = deleted_object.data["inReplyTo"] do
+              Object.decrease_replies_count(in_reply_to)
+            end
+
+            ActivityPub.stream_out(object)
+            ActivityPub.stream_out_participations(deleted_object, user)
+            :ok
+          end
+
+        %User{} ->
+          with {:ok, _} <- User.delete(deleted_object) do
+            :ok
+          end
+      end
+
+    if result == :ok do
+      Notification.create_notifications(object)
+      {:ok, object, meta}
+    else
+      {:error, result}
+    end
+  end
+
   # Nothing to do
   def handle(object, meta) do
     {:ok, object, meta}

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -735,36 +735,12 @@ def handle_incoming(
     end
   end
 
-  # TODO: We presently assume that any actor on the same origin domain as the object being
-  # deleted has the rights to delete that object.  A better way to validate whether or not
-  # the object should be deleted is to refetch the object URI, which should return either
-  # an error or a tombstone.  This would allow us to verify that a deletion actually took
-  # place.
   def handle_incoming(
-        %{"type" => "Delete", "object" => object_id, "actor" => actor, "id" => id} = data,
+        %{"type" => "Delete"} = data,
         _options
       ) do
-    object_id = Utils.get_ap_id(object_id)
-
-    with actor <- Containment.get_actor(data),
-         {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
-         {:ok, object} <- get_obj_helper(object_id),
-         :ok <- Containment.contain_origin(actor.ap_id, object.data),
-         {:ok, activity} <-
-           ActivityPub.delete(object, local: false, activity_id: id, actor: actor.ap_id) do
+    with {:ok, activity, _} <- Pipeline.common_pipeline(data, local: false) do
       {:ok, activity}
-    else
-      nil ->
-        case User.get_cached_by_ap_id(object_id) do
-          %User{ap_id: ^actor} = user ->
-            User.delete(user)
-
-          nil ->
-            :error
-        end
-
-      _e ->
-        :error
     end
   end
 

lib/pleroma/web/activity_pub/utils.ex

@@ -512,7 +512,7 @@ def get_latest_reaction(internal_activity_id, %{ap_id: ap_id}, emoji) do
   #### Announce-related helpers
 
   @doc """
-  Retruns an existing announce activity if the notice has already been announced
+  Returns an existing announce activity if the notice has already been announced
   """
   @spec get_existing_announce(String.t(), map()) :: Activity.t() | nil
   def get_existing_announce(actor, %{data: %{"id" => ap_id}}) do

lib/pleroma/web/admin_api/admin_api_controller.ex

@@ -17,6 +17,8 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
   alias Pleroma.User
   alias Pleroma.UserInviteToken
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Builder
+  alias Pleroma.Web.ActivityPub.Pipeline
   alias Pleroma.Web.ActivityPub.Relay
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.AdminAPI.AccountView
@@ -133,23 +135,20 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
 
   action_fallback(:errors)
 
-  def user_delete(%{assigns: %{user: admin}} = conn, %{"nickname" => nickname}) do
-    user = User.get_cached_by_nickname(nickname)
-    User.delete(user)
-
-    ModerationLog.insert_log(%{
-      actor: admin,
-      subject: [user],
-      action: "delete"
-    })
-
-    conn
-    |> json(nickname)
+  def user_delete(conn, %{"nickname" => nickname}) do
+    user_delete(conn, %{"nicknames" => [nickname]})
   end
 
   def user_delete(%{assigns: %{user: admin}} = conn, %{"nicknames" => nicknames}) do
-    users = nicknames |> Enum.map(&User.get_cached_by_nickname/1)
-    User.delete(users)
+    users =
+      nicknames
+      |> Enum.map(&User.get_cached_by_nickname/1)
+
+    users
+    |> Enum.each(fn user ->
+      {:ok, delete_data, _} = Builder.delete(admin, user.ap_id)
+      Pipeline.common_pipeline(delete_data, local: true)
+    end)
 
     ModerationLog.insert_log(%{
       actor: admin,

lib/pleroma/web/common_api/common_api.ex

@@ -79,8 +79,8 @@ def delete(activity_id, user) do
            {:find_activity, Activity.get_by_id_with_object(activity_id)},
          %Object{} = object <- Object.normalize(activity),
          true <- User.superuser?(user) || user.ap_id == object.data["actor"],
-         {:ok, _} <- unpin(activity_id, user),
-         {:ok, delete} <- ActivityPub.delete(object) do
+         {:ok, delete_data, _} <- Builder.delete(user, object.data["id"]),
+         {:ok, delete, _} <- Pipeline.common_pipeline(delete_data, local: true) do
       {:ok, delete}
     else
       {:find_activity, _} -> {:error, :not_found}

test/tasks/user_test.exs

@@ -4,14 +4,17 @@
 
 defmodule Mix.Tasks.Pleroma.UserTest do
   alias Pleroma.Repo
+  alias Pleroma.Tests.ObanHelpers
   alias Pleroma.User
   alias Pleroma.Web.OAuth.Authorization
   alias Pleroma.Web.OAuth.Token
 
   use Pleroma.DataCase
+  use Oban.Testing, repo: Pleroma.Repo
 
-  import Pleroma.Factory
   import ExUnit.CaptureIO
+  import Mock
+  import Pleroma.Factory
 
   setup_all do
     Mix.shell(Mix.Shell.Process)
@@ -87,12 +90,17 @@ test "user is not created" do
     test "user is deleted" do
       user = insert(:user)
 
+      with_mock Pleroma.Web.Federator,
+        publish: fn _ -> nil end do
         Mix.Tasks.Pleroma.User.run(["rm", user.nickname])
+        ObanHelpers.perform_all()
 
         assert_received {:mix_shell, :info, [message]}
         assert message =~ " deleted"
-
         assert %{deactivated: true} = User.get_by_nickname(user.nickname)
+
+        assert called(Pleroma.Web.Federator.publish(:_))
+      end
     end
 
     test "no user to delete" do

test/user_test.exs

@@ -15,7 +15,6 @@ defmodule Pleroma.UserTest do
   use Pleroma.DataCase
   use Oban.Testing, repo: Pleroma.Repo
 
-  import Mock
   import Pleroma.Factory
   import ExUnit.CaptureLog
 
@@ -1131,7 +1130,7 @@ test ".delete_user_activities deletes all create activities", %{user: user} do
 
       User.delete_user_activities(user)
 
-      # TODO: Remove favorites, repeats, delete activities.
+      # TODO: Test removal favorites, repeats, delete activities.
       refute Activity.get_by_id(activity.id)
     end
 
@@ -1170,31 +1169,6 @@ test "it deactivates a user, all follow relationships and all activities", %{use
       refute Activity.get_by_id(like_two.id)
       refute Activity.get_by_id(repeat.id)
     end
-
-    test_with_mock "it sends out User Delete activity",
-                   %{user: user},
-                   Pleroma.Web.ActivityPub.Publisher,
-                   [:passthrough],
-                   [] do
-      Pleroma.Config.put([:instance, :federating], true)
-
-      {:ok, follower} = User.get_or_fetch_by_ap_id("http://mastodon.example.org/users/admin")
-      {:ok, _} = User.follow(follower, user)
-
-      {:ok, job} = User.delete(user)
-      {:ok, _user} = ObanHelpers.perform(job)
-
-      assert ObanHelpers.member?(
-               %{
-                 "op" => "publish_one",
-                 "params" => %{
-                   "inbox" => "http://mastodon.example.org/inbox",
-                   "id" => "pleroma:fakeid"
-                 }
-               },
-               all_enqueued(worker: Pleroma.Workers.PublisherWorker)
-             )
-    end
   end
 
   test "get_public_key_for_ap_id fetches a user that's not in the db" do

test/web/activity_pub/activity_pub_test.exs

@@ -1332,143 +1332,6 @@ test "creates an undo activity for the last block" do
     end
   end
 
-  describe "deletion" do
-    setup do: clear_config([:instance, :rewrite_policy])
-
-    test "it reverts deletion on error" do
-      note = insert(:note_activity)
-      object = Object.normalize(note)
-
-      with_mock(Utils, [:passthrough], maybe_federate: fn _ -> {:error, :reverted} end) do
-        assert {:error, :reverted} = ActivityPub.delete(object)
-      end
-
-      assert Repo.aggregate(Activity, :count, :id) == 1
-      assert Repo.get(Object, object.id) == object
-      assert Activity.get_by_id(note.id) == note
-    end
-
-    test "it creates a delete activity and deletes the original object" do
-      note = insert(:note_activity)
-      object = Object.normalize(note)
-      {:ok, delete} = ActivityPub.delete(object)
-
-      assert delete.data["type"] == "Delete"
-      assert delete.data["actor"] == note.data["actor"]
-      assert delete.data["object"] == object.data["id"]
-
-      assert Activity.get_by_id(delete.id) != nil
-
-      assert Repo.get(Object, object.id).data["type"] == "Tombstone"
-    end
-
-    test "it doesn't fail when an activity was already deleted" do
-      {:ok, delete} = insert(:note_activity) |> Object.normalize() |> ActivityPub.delete()
-
-      assert {:ok, ^delete} = delete |> Object.normalize() |> ActivityPub.delete()
-    end
-
-    test "decrements user note count only for public activities" do
-      user = insert(:user, note_count: 10)
-
-      {:ok, a1} =
-        CommonAPI.post(User.get_cached_by_id(user.id), %{
-          "status" => "yeah",
-          "visibility" => "public"
-        })
-
-      {:ok, a2} =
-        CommonAPI.post(User.get_cached_by_id(user.id), %{
-          "status" => "yeah",
-          "visibility" => "unlisted"
-        })
-
-      {:ok, a3} =
-        CommonAPI.post(User.get_cached_by_id(user.id), %{
-          "status" => "yeah",
-          "visibility" => "private"
-        })
-
-      {:ok, a4} =
-        CommonAPI.post(User.get_cached_by_id(user.id), %{
-          "status" => "yeah",
-          "visibility" => "direct"
-        })
-
-      {:ok, _} = Object.normalize(a1) |> ActivityPub.delete()
-      {:ok, _} = Object.normalize(a2) |> ActivityPub.delete()
-      {:ok, _} = Object.normalize(a3) |> ActivityPub.delete()
-      {:ok, _} = Object.normalize(a4) |> ActivityPub.delete()
-
-      user = User.get_cached_by_id(user.id)
-      assert user.note_count == 10
-    end
-
-    test "it creates a delete activity and checks that it is also sent to users mentioned by the deleted object" do
-      user = insert(:user)
-      note = insert(:note_activity)
-      object = Object.normalize(note)
-
-      {:ok, object} =
-        object
-        |> Object.change(%{
-          data: %{
-            "actor" => object.data["actor"],
-            "id" => object.data["id"],
-            "to" => [user.ap_id],
-            "type" => "Note"
-          }
-        })
-        |> Object.update_and_set_cache()
-
-      {:ok, delete} = ActivityPub.delete(object)
-
-      assert user.ap_id in delete.data["to"]
-    end
-
-    test "decreases reply count" do
-      user = insert(:user)
-      user2 = insert(:user)
-
-      {:ok, activity} = CommonAPI.post(user, %{"status" => "1", "visibility" => "public"})
-      reply_data = %{"status" => "1", "in_reply_to_status_id" => activity.id}
-      ap_id = activity.data["id"]
-
-      {:ok, public_reply} = CommonAPI.post(user2, Map.put(reply_data, "visibility", "public"))
-      {:ok, unlisted_reply} = CommonAPI.post(user2, Map.put(reply_data, "visibility", "unlisted"))
-      {:ok, private_reply} = CommonAPI.post(user2, Map.put(reply_data, "visibility", "private"))
-      {:ok, direct_reply} = CommonAPI.post(user2, Map.put(reply_data, "visibility", "direct"))
-
-      _ = CommonAPI.delete(direct_reply.id, user2)
-      assert %{data: data, object: object} = Activity.get_by_ap_id_with_object(ap_id)
-      assert object.data["repliesCount"] == 2
-
-      _ = CommonAPI.delete(private_reply.id, user2)
-      assert %{data: data, object: object} = Activity.get_by_ap_id_with_object(ap_id)
-      assert object.data["repliesCount"] == 2
-
-      _ = CommonAPI.delete(public_reply.id, user2)
-      assert %{data: data, object: object} = Activity.get_by_ap_id_with_object(ap_id)
-      assert object.data["repliesCount"] == 1
-
-      _ = CommonAPI.delete(unlisted_reply.id, user2)
-      assert %{data: data, object: object} = Activity.get_by_ap_id_with_object(ap_id)
-      assert object.data["repliesCount"] == 0
-    end
-
-    test "it passes delete activity through MRF before deleting the object" do
-      Pleroma.Config.put([:instance, :rewrite_policy], Pleroma.Web.ActivityPub.MRF.DropPolicy)
-
-      note = insert(:note_activity)
-      object = Object.normalize(note)
-
-      {:error, {:reject, _}} = ActivityPub.delete(object)
-
-      assert Activity.get_by_id(note.id)
-      assert Repo.get(Object, object.id).data["type"] == object.data["type"]
-    end
-  end
-
   describe "timeline post-processing" do
     test "it filters broken threads" do
       user1 = insert(:user)

test/web/activity_pub/object_validator_test.exs

@@ -1,6 +1,8 @@
 defmodule Pleroma.Web.ActivityPub.ObjectValidatorTest do
   use Pleroma.DataCase
 
+  alias Pleroma.Object
+  alias Pleroma.Web.ActivityPub.Builder
   alias Pleroma.Web.ActivityPub.ObjectValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.LikeValidator
   alias Pleroma.Web.ActivityPub.Utils
@@ -8,6 +10,98 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidatorTest do
 
   import Pleroma.Factory
 
+  describe "deletes" do
+    setup do
+      user = insert(:user)
+      {:ok, post_activity} = CommonAPI.post(user, %{"status" => "cancel me daddy"})
+
+      {:ok, valid_post_delete, _} = Builder.delete(user, post_activity.data["object"])
+      {:ok, valid_user_delete, _} = Builder.delete(user, user.ap_id)
+
+      %{user: user, valid_post_delete: valid_post_delete, valid_user_delete: valid_user_delete}
+    end
+
+    test "it is valid for a post deletion", %{valid_post_delete: valid_post_delete} do
+      {:ok, valid_post_delete, _} = ObjectValidator.validate(valid_post_delete, [])
+
+      assert valid_post_delete["deleted_activity_id"]
+    end
+
+    test "it is invalid if the object isn't in a list of certain types", %{
+      valid_post_delete: valid_post_delete
+    } do
+      object = Object.get_by_ap_id(valid_post_delete["object"])
+
+      data =
+        object.data
+        |> Map.put("type", "Like")
+
+      {:ok, _object} =
+        object
+        |> Ecto.Changeset.change(%{data: data})
+        |> Object.update_and_set_cache()
+
+      {:error, cng} = ObjectValidator.validate(valid_post_delete, [])
+      assert {:object, {"object not in allowed types", []}} in cng.errors
+    end
+
+    test "it is valid for a user deletion", %{valid_user_delete: valid_user_delete} do
+      assert match?({:ok, _, _}, ObjectValidator.validate(valid_user_delete, []))
+    end
+
+    test "it's invalid if the id is missing", %{valid_post_delete: valid_post_delete} do
+      no_id =
+        valid_post_delete
+        |> Map.delete("id")
+
+      {:error, cng} = ObjectValidator.validate(no_id, [])
+
+      assert {:id, {"can't be blank", [validation: :required]}} in cng.errors
+    end
+
+    test "it's invalid if the object doesn't exist", %{valid_post_delete: valid_post_delete} do
+      missing_object =
+        valid_post_delete
+        |> Map.put("object", "http://does.not/exist")
+
+      {:error, cng} = ObjectValidator.validate(missing_object, [])
+
+      assert {:object, {"can't find object", []}} in cng.errors
+    end
+
+    test "it's invalid if the actor of the object and the actor of delete are from different domains",
+         %{valid_post_delete: valid_post_delete} do
+      valid_user = insert(:user)
+
+      valid_other_actor =
+        valid_post_delete
+        |> Map.put("actor", valid_user.ap_id)
+
+      assert match?({:ok, _, _}, ObjectValidator.validate(valid_other_actor, []))
+
+      invalid_other_actor =
+        valid_post_delete
+        |> Map.put("actor", "https://gensokyo.2hu/users/raymoo")
+
+      {:error, cng} = ObjectValidator.validate(invalid_other_actor, [])
+
+      assert {:actor, {"is not allowed to delete object", []}} in cng.errors
+    end
+
+    test "it's valid if the actor of the object is a local superuser",
+         %{valid_post_delete: valid_post_delete} do
+      user =
+        insert(:user, local: true, is_moderator: true, ap_id: "https://gensokyo.2hu/users/raymoo")
+
+      valid_other_actor =
+        valid_post_delete
+        |> Map.put("actor", user.ap_id)
+
+      {:ok, _, meta} = ObjectValidator.validate(valid_other_actor, [])
+      assert meta[:do_not_federate]
+    end
+  end
+
   describe "likes" do
     setup do
       user = insert(:user)

test/web/activity_pub/object_validators/types/recipients_test.exs

@@ -0,0 +1,27 @@
+defmodule Pleroma.Web.ObjectValidators.Types.RecipientsTest do
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types.Recipients
+  use Pleroma.DataCase
+
+  test "it asserts that all elements of the list are object ids" do
+    list = ["https://lain.com/users/lain", "invalid"]
+
+    assert :error == Recipients.cast(list)
+  end
+
+  test "it works with a list" do
+    list = ["https://lain.com/users/lain"]
+    assert {:ok, list} == Recipients.cast(list)
+  end
+
+  test "it works with a list with whole objects" do
+    list = ["https://lain.com/users/lain", %{"id" => "https://gensokyo.2hu/users/raymoo"}]
+    resulting_list = ["https://gensokyo.2hu/users/raymoo", "https://lain.com/users/lain"]
+    assert {:ok, resulting_list} == Recipients.cast(list)
+  end
+
+  test "it turns a single string into a list" do
+    recipient = "https://lain.com/users/lain"
+
+    assert {:ok, [recipient]} == Recipients.cast(recipient)
+  end
+end

test/web/activity_pub/side_effects_test.exs

@@ -3,17 +3,74 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.ActivityPub.SideEffectsTest do
+  use Oban.Testing, repo: Pleroma.Repo
   use Pleroma.DataCase
 
+  alias Pleroma.Activity
   alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.Repo
+  alias Pleroma.Tests.ObanHelpers
+  alias Pleroma.User
   alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Builder
   alias Pleroma.Web.ActivityPub.SideEffects
   alias Pleroma.Web.CommonAPI
 
   import Pleroma.Factory
+  import Mock
+
+  describe "delete objects" do
+    setup do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, op} = CommonAPI.post(other_user, %{"status" => "big oof"})
+      {:ok, post} = CommonAPI.post(user, %{"status" => "hey", "in_reply_to_id" => op})
+      object = Object.normalize(post)
+      {:ok, delete_data, _meta} = Builder.delete(user, object.data["id"])
+      {:ok, delete_user_data, _meta} = Builder.delete(user, user.ap_id)
+      {:ok, delete, _meta} = ActivityPub.persist(delete_data, local: true)
+      {:ok, delete_user, _meta} = ActivityPub.persist(delete_user_data, local: true)
+      %{user: user, delete: delete, post: post, object: object, delete_user: delete_user, op: op}
+    end
+
+    test "it handles object deletions", %{
+      delete: delete,
+      post: post,
+      object: object,
+      user: user,
+      op: op
+    } do
+      with_mock Pleroma.Web.ActivityPub.ActivityPub, [:passthrough],
+        stream_out: fn _ -> nil end,
+        stream_out_participations: fn _, _ -> nil end do
+        {:ok, delete, _} = SideEffects.handle(delete)
+        user = User.get_cached_by_ap_id(object.data["actor"])
+
+        assert called(Pleroma.Web.ActivityPub.ActivityPub.stream_out(delete))
+        assert called(Pleroma.Web.ActivityPub.ActivityPub.stream_out_participations(object, user))
+      end
+
+      object = Object.get_by_id(object.id)
+      assert object.data["type"] == "Tombstone"
+      refute Activity.get_by_id(post.id)
+
+      user = User.get_by_id(user.id)
+      assert user.note_count == 0
+
+      object = Object.normalize(op.data["object"], false)
+
+      assert object.data["repliesCount"] == 0
+    end
+
+    test "it handles user deletions", %{delete_user: delete, user: user} do
+      {:ok, _delete, _} = SideEffects.handle(delete)
+      ObanHelpers.perform_all()
+
+      assert User.get_cached_by_ap_id(user.ap_id).deactivated
+    end
+  end
 
   describe "like objects" do
     setup do

test/web/activity_pub/transmogrifier/delete_handling_test.exs

@@ -0,0 +1,86 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.Transmogrifier.DeleteHandlingTest do
+  use Oban.Testing, repo: Pleroma.Repo
+  use Pleroma.DataCase
+
+  alias Pleroma.Activity
+  alias Pleroma.Object
+  alias Pleroma.Tests.ObanHelpers
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.Transmogrifier
+
+  import Pleroma.Factory
+
+  setup_all do
+    Tesla.Mock.mock_global(fn env -> apply(HttpRequestMock, :request, [env]) end)
+    :ok
+  end
+
+  test "it works for incoming deletes" do
+    activity = insert(:note_activity)
+    deleting_user = insert(:user)
+
+    data =
+      File.read!("test/fixtures/mastodon-delete.json")
+      |> Poison.decode!()
+      |> Map.put("actor", deleting_user.ap_id)
+      |> put_in(["object", "id"], activity.data["object"])
+
+    {:ok, %Activity{actor: actor, local: false, data: %{"id" => id}}} =
+      Transmogrifier.handle_incoming(data)
+
+    assert id == data["id"]
+
+    # We delete the Create activity because we base our timelines on it.
+    # This should be changed after we unify objects and activities
+    refute Activity.get_by_id(activity.id)
+    assert actor == deleting_user.ap_id
+
+    # Objects are replaced by a tombstone object.
+    object = Object.normalize(activity.data["object"])
+    assert object.data["type"] == "Tombstone"
+  end
+
+  test "it fails for incoming deletes with spoofed origin" do
+    activity = insert(:note_activity)
+    %{ap_id: ap_id} = insert(:user, ap_id: "https://gensokyo.2hu/users/raymoo")
+
+    data =
+      File.read!("test/fixtures/mastodon-delete.json")
+      |> Poison.decode!()
+      |> Map.put("actor", ap_id)
+      |> put_in(["object", "id"], activity.data["object"])
+
+    assert match?({:error, _}, Transmogrifier.handle_incoming(data))
+  end
+
+  @tag capture_log: true
+  test "it works for incoming user deletes" do
+    %{ap_id: ap_id} = insert(:user, ap_id: "http://mastodon.example.org/users/admin")
+
+    data =
+      File.read!("test/fixtures/mastodon-delete-user.json")
+      |> Poison.decode!()
+
+    {:ok, _} = Transmogrifier.handle_incoming(data)
+    ObanHelpers.perform_all()
+
+    assert User.get_cached_by_ap_id(ap_id).deactivated
+  end
+
+  test "it fails for incoming user deletes with spoofed origin" do
+    %{ap_id: ap_id} = insert(:user)
+
+    data =
+      File.read!("test/fixtures/mastodon-delete-user.json")
+      |> Poison.decode!()
+      |> Map.put("actor", ap_id)
+
+    assert match?({:error, _}, Transmogrifier.handle_incoming(data))
+
+    assert User.get_cached_by_ap_id(ap_id)
+  end
+end

test/web/activity_pub/transmogrifier_test.exs

@@ -766,84 +766,6 @@ test "it works for incoming update activities which lock the account" do
       assert user.locked == true
     end
 
-    test "it works for incoming deletes" do
-      activity = insert(:note_activity)
-      deleting_user = insert(:user)
-
-      data =
-        File.read!("test/fixtures/mastodon-delete.json")
-        |> Poison.decode!()
-
-      object =
-        data["object"]
-        |> Map.put("id", activity.data["object"])
-
-      data =
-        data
-        |> Map.put("object", object)
-        |> Map.put("actor", deleting_user.ap_id)
-
-      {:ok, %Activity{actor: actor, local: false, data: %{"id" => id}}} =
-        Transmogrifier.handle_incoming(data)
-
-      assert id == data["id"]
-      refute Activity.get_by_id(activity.id)
-      assert actor == deleting_user.ap_id
-    end
-
-    test "it fails for incoming deletes with spoofed origin" do
-      activity = insert(:note_activity)
-
-      data =
-        File.read!("test/fixtures/mastodon-delete.json")
-        |> Poison.decode!()
-
-      object =
-        data["object"]
-        |> Map.put("id", activity.data["object"])
-
-      data =
-        data
-        |> Map.put("object", object)
-
-      assert capture_log(fn ->
-               :error = Transmogrifier.handle_incoming(data)
-             end) =~
-               "[error] Could not decode user at fetch http://mastodon.example.org/users/gargron, {:error, :nxdomain}"
-
-      assert Activity.get_by_id(activity.id)
-    end
-
-    @tag capture_log: true
-    test "it works for incoming user deletes" do
-      %{ap_id: ap_id} =
-        insert(:user, ap_id: "http://mastodon.example.org/users/admin", local: false)
-
-      data =
-        File.read!("test/fixtures/mastodon-delete-user.json")
-        |> Poison.decode!()
-
-      {:ok, _} = Transmogrifier.handle_incoming(data)
-      ObanHelpers.perform_all()
-
-      refute User.get_cached_by_ap_id(ap_id)
-    end
-
-    test "it fails for incoming user deletes with spoofed origin" do
-      %{ap_id: ap_id} = insert(:user)
-
-      data =
-        File.read!("test/fixtures/mastodon-delete-user.json")
-        |> Poison.decode!()
-        |> Map.put("actor", ap_id)
-
-      assert capture_log(fn ->
-               assert :error == Transmogrifier.handle_incoming(data)
-             end) =~ "Object containment failed"
-
-      assert User.get_cached_by_ap_id(ap_id)
-    end
-
     test "it works for incoming unannounces with an existing notice" do
       user = insert(:user)
       {:ok, activity} = CommonAPI.post(user, %{"status" => "hey"})

test/web/admin_api/admin_api_controller_test.exs

@@ -6,8 +6,9 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIControllerTest do
   use Pleroma.Web.ConnCase
   use Oban.Testing, repo: Pleroma.Repo
 
-  import Pleroma.Factory
   import ExUnit.CaptureLog
+  import Mock
+  import Pleroma.Factory
 
   alias Pleroma.Activity
   alias Pleroma.Config
@@ -147,17 +148,26 @@ test "GET /api/pleroma/admin/users/:nickname requires " <>
     test "single user", %{admin: admin, conn: conn} do
       user = insert(:user)
 
+      with_mock Pleroma.Web.Federator,
+        publish: fn _ -> nil end do
         conn =
           conn
           |> put_req_header("accept", "application/json")
           |> delete("/api/pleroma/admin/users?nickname=#{user.nickname}")
 
+        ObanHelpers.perform_all()
+
+        assert User.get_by_nickname(user.nickname).deactivated
+
         log_entry = Repo.one(ModerationLog)
 
         assert ModerationLog.get_log_entry_message(log_entry) ==
                  "@#{admin.nickname} deleted users: @#{user.nickname}"
 
-      assert json_response(conn, 200) == user.nickname
+        assert json_response(conn, 200) == [user.nickname]
+
+        assert called(Pleroma.Web.Federator.publish(:_))
+      end
     end
 
     test "multiple users", %{admin: admin, conn: conn} do

test/web/common_api/common_api_test.exs

@@ -9,11 +9,13 @@ defmodule Pleroma.Web.CommonAPITest do
   alias Pleroma.Object
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Transmogrifier
   alias Pleroma.Web.ActivityPub.Visibility
   alias Pleroma.Web.AdminAPI.AccountView
   alias Pleroma.Web.CommonAPI
 
   import Pleroma.Factory
+  import Mock
 
   require Pleroma.Constants
 
@@ -21,6 +23,84 @@ defmodule Pleroma.Web.CommonAPITest do
   setup do: clear_config([:instance, :limit])
   setup do: clear_config([:instance, :max_pinned_statuses])
 
+  describe "deletion" do
+    test "it allows users to delete their posts" do
+      user = insert(:user)
+
+      {:ok, post} = CommonAPI.post(user, %{"status" => "namu amida butsu"})
+
+      with_mock Pleroma.Web.Federator,
+        publish: fn _ -> nil end do
+        assert {:ok, delete} = CommonAPI.delete(post.id, user)
+        assert delete.local
+        assert called(Pleroma.Web.Federator.publish(delete))
+      end
+
+      refute Activity.get_by_id(post.id)
+    end
+
+    test "it does not allow a user to delete their posts" do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, post} = CommonAPI.post(user, %{"status" => "namu amida butsu"})
+
+      assert {:error, "Could not delete"} = CommonAPI.delete(post.id, other_user)
+      assert Activity.get_by_id(post.id)
+    end
+
+    test "it allows moderators to delete other user's posts" do
+      user = insert(:user)
+      moderator = insert(:user, is_moderator: true)
+
+      {:ok, post} = CommonAPI.post(user, %{"status" => "namu amida butsu"})
+
+      assert {:ok, delete} = CommonAPI.delete(post.id, moderator)
+      assert delete.local
+
+      refute Activity.get_by_id(post.id)
+    end
+
+    test "it allows admins to delete other user's posts" do
+      user = insert(:user)
+      moderator = insert(:user, is_admin: true)
+
+      {:ok, post} = CommonAPI.post(user, %{"status" => "namu amida butsu"})
+
+      assert {:ok, delete} = CommonAPI.delete(post.id, moderator)
+      assert delete.local
+
+      refute Activity.get_by_id(post.id)
+    end
+
+    test "superusers deleting non-local posts won't federate the delete" do
+      # This is the user of the ingested activity
+      _user =
+        insert(:user,
+          local: false,
+          ap_id: "http://mastodon.example.org/users/admin",
+          last_refreshed_at: NaiveDateTime.utc_now()
+        )
+
+      moderator = insert(:user, is_admin: true)
+
+      data =
+        File.read!("test/fixtures/mastodon-post-activity.json")
+        |> Jason.decode!()
+
+      {:ok, post} = Transmogrifier.handle_incoming(data)
+
+      with_mock Pleroma.Web.Federator,
+        publish: fn _ -> nil end do
+        assert {:ok, delete} = CommonAPI.delete(post.id, moderator)
+        assert delete.local
+        refute called(Pleroma.Web.Federator.publish(:_))
+      end
+
+      refute Activity.get_by_id(post.id)
+    end
+  end
+
   test "favoriting race condition" do
     user = insert(:user)
     users_serial = insert_list(10, :user)

test/web/streamer/streamer_test.exs

@@ -210,6 +210,12 @@ test "it sends to public" do
     Worker.push_to_socket(topics, "public", activity)
 
     Task.await(task)
+  end
+
+  test "works for deletions" do
+    user = insert(:user)
+    other_user = insert(:user)
+    {:ok, activity} = CommonAPI.post(other_user, %{"status" => "Test"})
 
     task =
       Task.async(fn ->