Fix edge cases

lib/pleroma/constants.ex

@@ -42,6 +42,18 @@ defmodule Pleroma.Constants do
     ]
   )
 
+  const(status_object_types,
+    do: [
+      "Note",
+      "Question",
+      "Audio",
+      "Video",
+      "Event",
+      "Article",
+      "Page"
+    ]
+  )
+
   const(updatable_object_types,
     do: [
       "Note",

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

@@ -31,8 +31,8 @@ defp config_unlist_shortcode do
   def history_awareness, do: :manual
 
   @impl Pleroma.Web.ActivityPub.MRF.Policy
-  def filter(%{"type" => type, "object" => %{} = object} = message)
-      when type in ["Create", "Update"] do
+  def filter(%{"type" => type, "object" => %{"type" => objtype} = object} = message)
+      when type in ["Create", "Update"] and objtype in Pleroma.Constants.status_object_types() do
     with {:ok, object} <-
            Updater.do_with_history(object, fn object ->
              {:ok, process_remove(object, :url, config_remove_url())}
@@ -102,7 +102,11 @@ defp process_remove(object, :shortcode, patterns) do
   end
 
   defp process_remove_impl(object, extract_from_tag, extract_from_emoji, patterns) do
-    processed_tag =
+    object =
+      if object["tag"] do
+        Map.put(
+          object,
+          "tag",
           Enum.filter(
             object["tag"],
             fn
@@ -119,9 +123,16 @@ defp process_remove_impl(object, extract_from_tag, extract_from_emoji, patterns)
                 true
             end
           )
+        )
+      else
+        object
+      end
 
-    processed_emoji =
+    object =
       if object["emoji"] do
+        Map.put(
+          object,
+          "emoji",
           object["emoji"]
           |> Enum.reduce(%{}, fn {name, url} = emoji, acc ->
             if not match_any?(extract_from_emoji.(emoji), patterns) do
@@ -130,18 +141,12 @@ defp process_remove_impl(object, extract_from_tag, extract_from_emoji, patterns)
               acc
             end
           end)
+        )
       else
-        nil
+        object
       end
 
-    if processed_emoji do
     object
-      |> Map.put("tag", processed_tag)
-      |> Map.put("emoji", processed_emoji)
-    else
-      object
-      |> Map.put("tag", processed_tag)
-    end
   end
 
   defp matched_emoji_checker(urls, shortcodes) do

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

@@ -389,4 +389,37 @@ test "processes status with history" do
              } = filtered
     end
   end
+
+  describe "edge cases" do
+    setup do
+      clear_config([:mrf_emoji, :remove_url], [
+        "https://example.org/test.png",
+        ~r{/biribiri/mikoto_smile[23]\.png},
+        "nekomimi_girl_emoji"
+      ])
+
+      :ok
+    end
+
+    test "non-statuses" do
+      answer = @status_data |> put_in(["object", "type"], "Answer")
+      {:ok, filtered} = MRF.filter_one(EmojiPolicy, answer)
+
+      assert filtered == answer
+    end
+
+    test "without tag" do
+      status = @status_data |> Map.put("object", Map.drop(@status_data["object"], ["tag"]))
+      {:ok, filtered} = MRF.filter_one(EmojiPolicy, status)
+
+      refute Map.has_key?(filtered["object"], "tag")
+    end
+
+    test "without emoji" do
+      status = @status_data |> Map.put("object", Map.drop(@status_data["object"], ["emoji"]))
+      {:ok, filtered} = MRF.filter_one(EmojiPolicy, status)
+
+      refute Map.has_key?(filtered["object"], "emoji")
+    end
+  end
 end