Add ForceMention mrf

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

changelog.d/force-mention-mrf.add

@@ -0,0 +1 @@
+Add ForceMention MRF

config/config.exs

@@ -415,6 +415,10 @@ config :pleroma, :mrf_follow_bot, follower_nickname: nil
 
 config :pleroma, :mrf_inline_quote, template: "<bdi>RT:</bdi> {url}"
 
+config :pleroma, :mrf_force_mention,
+  mention_parent: true,
+  mention_quoted: true
+
 config :pleroma, :rich_media,
   enabled: true,
   ignore_hosts: [],

docs/configuration/cheatsheet.md

@@ -161,7 +161,8 @@ To add configuration to your config file, you can copy it from the base config.
     * `Pleroma.Web.ActivityPub.MRF.KeywordPolicy`: Rejects or removes from the federated timeline or replaces keywords. (See [`:mrf_keyword`](#mrf_keyword)).
     * `Pleroma.Web.ActivityPub.MRF.ForceMentionsInContent`: Forces every mentioned user to be reflected in the post content.
     * `Pleroma.Web.ActivityPub.MRF.InlineQuotePolicy`: Forces quote post URLs to be reflected in the message content inline.
-    * `Pleroma.Web.ActivityPub.MRF.QuoteToLinkTagPolicy`: Force a Link tag for posts quoting another post. (may break outgoing federation of quote posts with older Pleroma versions)
+    * `Pleroma.Web.ActivityPub.MRF.QuoteToLinkTagPolicy`: Force a Link tag for posts quoting another post. (may break outgoing federation of quote posts with older Pleroma versions).
+    * `Pleroma.Web.ActivityPub.MRF.ForceMention`: Forces posts to include a mention of the author of parent post or the author of quoted post.
 * `transparency`: Make the content of your Message Rewrite Facility settings public (via nodeinfo).
 * `transparency_exclusions`: Exclude specific instance names from MRF transparency.  The use of the exclusions feature will be disclosed in nodeinfo as a boolean value.
 
@@ -272,6 +273,10 @@ Notes:
 #### :mrf_inline_quote
 * `template`: The template to append to the post. `{url}` will be replaced with the actual link to the quoted post. Default: `<bdi>RT:</bdi> {url}`
 
+#### :mrf_force_mention
+* `mention_parent`: Whether to append mention of parent post author
+* `mention_quoted`: Whether to append mention of parent quoted author
+
 ### :activitypub
 * `unfollow_blocked`: Whether blocks result in people getting unfollowed
 * `outgoing_blocks`: Whether to federate blocks to other instances

lib/pleroma/web/activity_pub/mrf/force_mention.ex

@@ -0,0 +1,59 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2024 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.ForceMention do
+  require Pleroma.Constants
+
+  alias Pleroma.Config
+  alias Pleroma.Object
+  alias Pleroma.User
+
+  @behaviour Pleroma.Web.ActivityPub.MRF.Policy
+
+  defp get_author(url) do
+    with %Object{data: %{"actor" => actor}} <- Object.normalize(url, fetch: false),
+         %User{ap_id: ap_id, nickname: nickname} <- User.get_cached_by_ap_id(actor) do
+      %{"type" => "Mention", "href" => ap_id, "name" => "@#{nickname}"}
+    else
+      _ -> nil
+    end
+  end
+
+  defp prepend_author(tags, _, false), do: tags
+
+  defp prepend_author(tags, nil, _), do: tags
+
+  defp prepend_author(tags, url, _) do
+    actor = get_author(url)
+
+    if not is_nil(actor) do
+      [actor | tags]
+    else
+      tags
+    end
+  end
+
+  @impl true
+  def filter(%{"type" => "Create", "object" => %{"tag" => tag} = object} = activity) do
+    tag =
+      tag
+      |> prepend_author(
+        object["inReplyTo"],
+        Config.get([:mrf_force_mention, :mention_parent, true])
+      )
+      |> prepend_author(
+        object["quoteUrl"],
+        Config.get([:mrf_force_mention, :mention_quoted, true])
+      )
+      |> Enum.uniq()
+
+    {:ok, put_in(activity["object"]["tag"], tag)}
+  end
+
+  @impl true
+  def filter(object), do: {:ok, object}
+
+  @impl true
+  def describe, do: {:ok, %{}}
+end

test/fixtures/minds-invalid-mention-post.json

@@ -0,0 +1 @@
+{"@context":"https://www.w3.org/ns/activitystreams","type":"Note","id":"https://www.minds.com/api/activitypub/users/1198929502760083472/entities/urn:comment:1600926863310458883:0:0:0:1600932467852709903","attributedTo":"https://www.minds.com/api/activitypub/users/1198929502760083472","content":"\u003Ca class=\u0022u-url mention\u0022 href=\u0022https://www.minds.com/lain\u0022 target=\u0022_blank\u0022\u003E@lain\u003C/a\u003E corn syrup.","to":["https://www.w3.org/ns/activitystreams#Public"],"cc":["https://www.minds.com/api/activitypub/users/1198929502760083472/followers","https://lain.com/users/lain"],"tag":[{"type":"Mention","href":"https://www.minds.com/api/activitypub/users/464237775479123984","name":"@lain"}],"url":"https://www.minds.com/newsfeed/1600926863310458883?focusedCommentUrn=urn:comment:1600926863310458883:0:0:0:1600932467852709903","published":"2024-02-04T17:34:03+00:00","inReplyTo":"https://lain.com/objects/36254095-c839-4167-bcc2-b361d5de9198","source":{"content":"@lain corn syrup.","mediaType":"text/plain"}}

test/fixtures/minds-pleroma-mentioned-post.json

@@ -0,0 +1 @@
+{"@context":["https://www.w3.org/ns/activitystreams","https://lain.com/schemas/litepub-0.1.jsonld",{"@language":"und"}],"actor":"https://lain.com/users/lain","attachment":[],"attributedTo":"https://lain.com/users/lain","cc":["https://lain.com/users/lain/followers"],"content":"which diet is the best for cognitive dissonance","context":"https://lain.com/contexts/98c8a130-e813-4797-8973-600e80114317","conversation":"https://lain.com/contexts/98c8a130-e813-4797-8973-600e80114317","id":"https://lain.com/objects/36254095-c839-4167-bcc2-b361d5de9198","published":"2024-02-04T17:11:23.931890Z","repliesCount":11,"sensitive":null,"source":{"content":"which diet is the best for cognitive dissonance","mediaType":"text/plain"},"summary":"","tag":[],"to":["https://www.w3.org/ns/activitystreams#Public"],"type":"Note"}

test/pleroma/web/activity_pub/mrf/force_mention_test.exs

@@ -0,0 +1,73 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2024 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.ForceMentionTest do
+  use Pleroma.DataCase
+  require Pleroma.Constants
+
+  alias Pleroma.Web.ActivityPub.MRF.ForceMention
+
+  import Pleroma.Factory
+
+  test "adds mention to a reply" do
+    lain =
+      insert(:user, ap_id: "https://lain.com/users/lain", nickname: "lain@lain.com", local: false)
+
+    niobleoum =
+      insert(:user,
+        ap_id: "https://www.minds.com/api/activitypub/users/1198929502760083472",
+        nickname: "niobleoum@minds.com",
+        local: false
+      )
+
+    status = File.read!("test/fixtures/minds-pleroma-mentioned-post.json") |> Jason.decode!()
+
+    status_activity = %{
+      "type" => "Create",
+      "actor" => lain.ap_id,
+      "object" => status
+    }
+
+    Pleroma.Web.ActivityPub.Transmogrifier.handle_incoming(status_activity)
+
+    reply = File.read!("test/fixtures/minds-invalid-mention-post.json") |> Jason.decode!()
+
+    reply_activity = %{
+      "type" => "Create",
+      "actor" => niobleoum.ap_id,
+      "object" => reply
+    }
+
+    {:ok, %{"object" => %{"tag" => tag}}} = ForceMention.filter(reply_activity)
+
+    assert Enum.find(tag, fn %{"href" => href} -> href == lain.ap_id end)
+  end
+
+  test "adds mention to a quote" do
+    user1 = insert(:user, ap_id: "https://misskey.io/users/83ssedkv53")
+    user2 = insert(:user, ap_id: "https://misskey.io/users/7rkrarq81i")
+
+    status = File.read!("test/fixtures/tesla_mock/misskey.io_8vs6wxufd0.json") |> Jason.decode!()
+
+    status_activity = %{
+      "type" => "Create",
+      "actor" => user1.ap_id,
+      "object" => status
+    }
+
+    Pleroma.Web.ActivityPub.Transmogrifier.handle_incoming(status_activity)
+
+    quote_post = File.read!("test/fixtures/quote_post/misskey_quote_post.json") |> Jason.decode!()
+
+    quote_activity = %{
+      "type" => "Create",
+      "actor" => user2.ap_id,
+      "object" => quote_post
+    }
+
+    {:ok, %{"object" => %{"tag" => tag}}} = ForceMention.filter(quote_activity)
+
+    assert Enum.find(tag, fn %{"href" => href} -> href == user1.ap_id end)
+  end
+end