Conversation: Return full status object, id is a string.

lib/pleroma/web/mastodon_api/mastodon_api_controller.ex

@@ -1590,12 +1590,16 @@ def conversations(%{assigns: %{user: user}} = conn, params) do
 
     conversations =
       Enum.map(participations, fn participation ->
+        activity = Activity.get_by_id_with_object(participation.last_activity_id)
+
+        last_status = StatusView.render("status.json", %{activity: activity, for: user})
+
         %{
-          id: participation.id,
+          id: participation.id |> to_string(),
           # TODO: Add this.
           accounts: [],
           unread: !participation.read,
-          last_status: participation.last_activity_id
+          last_status: last_status
         }
       end)
 

test/web/mastodon_api/mastodon_api_controller_test.exs

@@ -334,8 +334,9 @@ test "Conversations", %{conn: conn} do
              }
            ] = response
 
+    assert is_binary(res_id)
     assert unread == true
-    assert res_last_status == direct.id
+    assert res_last_status["id"] == direct.id
 
     # Apparently undocumented API endpoint
     res_conn =
@@ -350,7 +351,7 @@ test "Conversations", %{conn: conn} do
     res_conn =
       conn
       |> assign(:user, user_one)
-      |> get("/api/v1/statuses/#{res_last_status}/context")
+      |> get("/api/v1/statuses/#{res_last_status["id"]}/context")
 
     assert %{"ancestors" => [], "descendants" => []} == json_response(res_conn, 200)
   end