Add support for a first reference in pinned objects

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -1662,6 +1662,36 @@ def maybe_handle_clashing_nickname(data) do
     end
   end
 
+  def pin_data_from_featured_collection(%{
+        "type" => "OrderedCollection",
+        "first" => first
+      }) do
+    with {:ok, page} <- Fetcher.fetch_and_contain_remote_object_from_id(first) do
+      page
+      |> Map.get("orderedItems")
+      |> Map.new(fn %{"id" => object_ap_id} -> {object_ap_id, NaiveDateTime.utc_now()} end)
+    else
+      e ->
+        Logger.error("Could not decode featured collection at fetch #{first}, #{inspect(e)}")
+        {:ok, %{}}
+    end
+  end
+
+  def pin_data_from_featured_collection(%{
+        "type" => "Collection",
+        "first" => first
+      }) do
+    with {:ok, page} <- Fetcher.fetch_and_contain_remote_object_from_id(first) do
+      page
+      |> Map.get("items")
+      |> Map.new(fn %{"id" => object_ap_id} -> {object_ap_id, NaiveDateTime.utc_now()} end)
+    else
+      e ->
+        Logger.error("Could not decode featured collection at fetch #{first}, #{inspect(e)}")
+        {:ok, %{}}
+    end
+  end
+
   def pin_data_from_featured_collection(%{
         "type" => type,
         "orderedItems" => objects

test/fixtures/friendica/friendica_featured_collection_first.json

@@ -26,5 +26,9 @@
     "type": "OrderedCollectionPage",
     "totalItems": 0,
     "partOf": "https://friendica.example.com/featured/raha",
-    "orderedItems": []
+    "orderedItems": [
+        {
+            "id": "http://inserted"
+        }
+     ]
 }

test/pleroma/web/activity_pub/activity_pub_test.exs

@@ -315,16 +315,15 @@ test "fetches user featured collection" do
   end
 
   test "fetches user featured collection using the first property" do
-    ap_id = "https://friendica.example.com/raha"
     featured_url = "https://friendica.example.com/raha/collections/featured"
-    first_url = "https://friendica.mnementh.co.uk/featured/spyro?page=1"
+    first_url = "https://friendica.example.com/featured/raha?page=1"
 
     featured_data =
       "test/fixtures/friendica/friendica_featured_collection.json"
       |> File.read!()
 
     page_data =
-      "test/fixtures/friendica/friendica_featured_collection.json"
+      "test/fixtures/friendica/friendica_featured_collection_first.json"
       |> File.read!()
 
     Tesla.Mock.mock(fn
@@ -337,9 +336,7 @@ test "fetches user featured collection using the first property" do
           body: featured_data,
           headers: [{"content-type", "application/activity+json"}]
         }
-    end)
 
-    Tesla.Mock.mock_global(fn
       %{
         method: :get,
         url: ^first_url
@@ -352,6 +349,7 @@ test "fetches user featured collection using the first property" do
     end)
 
     {:ok, data} = ActivityPub.fetch_and_prepare_featured_from_ap_id(featured_url)
+    assert Map.has_key?(data, "http://inserted")
   end
 
   test "it fetches the appropriate tag-restricted posts" do