From 0a337063e14a63b3ed80776b493e3c9c56dd95d1 Mon Sep 17 00:00:00 2001
From: Tusooa Zhu <tusooa@kazv.moe>
Date: Sat, 23 Jul 2022 22:23:57 -0400
Subject: [PATCH] Make ForceMentionsInContent history-aware

---
 .../mrf/force_mentions_in_content.ex          |  7 +-
 .../mrf/force_mentions_in_content_test.exs    | 95 +++++++++++++++++++
 2 files changed, 100 insertions(+), 2 deletions(-)

diff --git a/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex b/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex
index 255910b2f..70224561c 100644
--- a/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex
+++ b/lib/pleroma/web/activity_pub/mrf/force_mentions_in_content.ex
@@ -11,6 +11,9 @@ defmodule Pleroma.Web.ActivityPub.MRF.ForceMentionsInContent do
 
   @behaviour Pleroma.Web.ActivityPub.MRF.Policy
 
+  @impl true
+  def history_awareness, do: :auto
+
   defp do_extract({:a, attrs, _}, acc) do
     if Enum.find(attrs, fn {name, value} ->
          name == "class" && value in ["mention", "u-url mention", "mention u-url"]
@@ -74,11 +77,11 @@ defp clean_recipients(recipients, object) do
   @impl true
   def filter(
         %{
-          "type" => "Create",
+          "type" => type,
           "object" => %{"type" => "Note", "to" => to, "inReplyTo" => in_reply_to}
         } = object
       )
-      when is_list(to) and is_binary(in_reply_to) do
+      when type in ["Create", "Update"] and is_list(to) and is_binary(in_reply_to) do
     # image-only posts from pleroma apparently reach this MRF without the content field
     content = object["object"]["content"] || ""
 
diff --git a/test/pleroma/web/activity_pub/mrf/force_mentions_in_content_test.exs b/test/pleroma/web/activity_pub/mrf/force_mentions_in_content_test.exs
index 125b14a59..b349a4bb7 100644
--- a/test/pleroma/web/activity_pub/mrf/force_mentions_in_content_test.exs
+++ b/test/pleroma/web/activity_pub/mrf/force_mentions_in_content_test.exs
@@ -8,6 +8,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.ForceMentionsInContentTest do
 
   alias Pleroma.Constants
   alias Pleroma.Object
+  alias Pleroma.Web.ActivityPub.MRF
   alias Pleroma.Web.ActivityPub.MRF.ForceMentionsInContent
   alias Pleroma.Web.CommonAPI
 
@@ -161,4 +162,98 @@ test "with markdown formatting" do
     assert filtered ==
              "<p><span class=\"recipients-inline\"><span class=\"h-card\"><a class=\"u-url mention\" data-user=\"#{luigi.id}\" href=\"#{luigi.ap_id}\" rel=\"ugc\">@<span>luigi</span></a></span> </span>I'ma tired...</p>"
   end
+
+  test "aware of history" do
+    mario = insert(:user, nickname: "mario")
+    wario = insert(:user, nickname: "wario")
+
+    {:ok, post1} = CommonAPI.post(mario, %{status: "Letsa go!"})
+
+    activity = %{
+      "type" => "Create",
+      "actor" => wario.ap_id,
+      "object" => %{
+        "type" => "Note",
+        "actor" => wario.ap_id,
+        "content" => "WHA-HA!",
+        "to" => [
+          mario.ap_id,
+          Constants.as_public()
+        ],
+        "inReplyTo" => post1.object.data["id"],
+        "formerRepresentations" => %{
+          "orderedItems" => [
+            %{
+              "type" => "Note",
+              "actor" => wario.ap_id,
+              "content" => "WHA-HA!",
+              "to" => [
+                mario.ap_id,
+                Constants.as_public()
+              ],
+              "inReplyTo" => post1.object.data["id"]
+            }
+          ]
+        }
+      }
+    }
+
+    expected =
+      "<span class=\"recipients-inline\"><span class=\"h-card\"><a class=\"u-url mention\" data-user=\"#{mario.id}\" href=\"#{mario.ap_id}\" rel=\"ugc\">@<span>mario</span></a></span> </span>WHA-HA!"
+
+    assert {:ok,
+            %{
+              "object" => %{
+                "content" => ^expected,
+                "formerRepresentations" => %{"orderedItems" => [%{"content" => ^expected}]}
+              }
+            }} = MRF.filter_one(ForceMentionsInContent, activity)
+  end
+
+  test "works with Updates" do
+    mario = insert(:user, nickname: "mario")
+    wario = insert(:user, nickname: "wario")
+
+    {:ok, post1} = CommonAPI.post(mario, %{status: "Letsa go!"})
+
+    activity = %{
+      "type" => "Update",
+      "actor" => wario.ap_id,
+      "object" => %{
+        "type" => "Note",
+        "actor" => wario.ap_id,
+        "content" => "WHA-HA!",
+        "to" => [
+          mario.ap_id,
+          Constants.as_public()
+        ],
+        "inReplyTo" => post1.object.data["id"],
+        "formerRepresentations" => %{
+          "orderedItems" => [
+            %{
+              "type" => "Note",
+              "actor" => wario.ap_id,
+              "content" => "WHA-HA!",
+              "to" => [
+                mario.ap_id,
+                Constants.as_public()
+              ],
+              "inReplyTo" => post1.object.data["id"]
+            }
+          ]
+        }
+      }
+    }
+
+    expected =
+      "<span class=\"recipients-inline\"><span class=\"h-card\"><a class=\"u-url mention\" data-user=\"#{mario.id}\" href=\"#{mario.ap_id}\" rel=\"ugc\">@<span>mario</span></a></span> </span>WHA-HA!"
+
+    assert {:ok,
+            %{
+              "object" => %{
+                "content" => ^expected,
+                "formerRepresentations" => %{"orderedItems" => [%{"content" => ^expected}]}
+              }
+            }} = MRF.filter_one(ForceMentionsInContent, activity)
+  end
 end