TagValidator: Add test for Link tag

test/fixtures/fep-e232.json

@@ -0,0 +1,26 @@
+{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "type": "Create",
+  "actor": "https://example.org/users/alice",
+  "object": {
+    "id": "https://example.org/objects/10",
+    "type": "Note",
+    "attributedTo": "https://example.org/users/alice",
+    "content": "<p>test <a href=\"https://example.org/objects/9\">https://example.org/objects/9</a></p>",
+    "published": "2022-10-01T21:30:05.211215Z",
+    "tag": [
+      {
+        "name": "https://example.org/objects/9",
+        "type": "Link",
+        "href": "https://example.org/objects/9",
+        "mediaType": "application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\""
+      }
+    ],
+    "to": [
+      "https://www.w3.org/ns/activitystreams#Public"
+    ],
+    "cc": [
+      "https://example.org/users/alice/followers"
+    ]
+  }
+}

test/pleroma/web/activity_pub/transmogrifier_test.exs

@@ -123,6 +123,22 @@ test "it fixes both the Create and object contexts in a reply" do
 
       assert activity.data["context"] == object.data["context"]
     end
+
+    # https://codeberg.org/fediverse/fep/src/branch/main/feps/fep-e232.md
+    test "it accepts FEP-e232 link tags" do
+      insert(:user, ap_id: "https://example.org/users/alice")
+
+      message = File.read!("test/fixtures/fep-e232.json") |> Jason.decode!()
+
+      assert {:ok, activity} = Transmogrifier.handle_incoming(message)
+
+      object = Object.normalize(activity)
+      assert length(object.data["tag"]) == 1
+
+      tag = object.data["tag"] |> List.first()
+      assert tag["type"] == "Link"
+      assert tag["name"] == "https://example.org/objects/9"
+    end
   end
 
   describe "prepare outgoing" do