fix(reindex): open temporary document when file not in store after rename

After a file rename, the new file URI may not be open in Document.Store
when reindexing is triggered. This caused "not_open" errors and the
index was never updated, breaking references and go-to-definition for
renamed modules.

Add ensure_open/1 to temporarily open the file from disk if needed.

Author: scottming

apps/engine/lib/engine/code_mod/rename.ex

@@ -51,7 +51,7 @@ defmodule Engine.CodeMod.Rename do
 
   defp set_rename_progress(document_changes_list, client_name) do
     # Progress tracking is optional - if the infrastructure isn't running
-    # (e.g., in tests), we just skip it
+    # (e.g., in tests), we just skip it silently
     try do
       do_set_rename_progress(document_changes_list, client_name)
     rescue

apps/engine/lib/engine/commands/reindex.ex

@@ -54,8 +54,7 @@ defmodule Engine.Commands.Reindex do
     end
 
     defp entries_for_uri(uri) do
-      with {:ok, %Document{} = document, %Analysis{} = analysis} <-
-             Document.Store.fetch(uri, :analysis),
+      with {:ok, %Document{} = document, %Analysis{} = analysis} <- ensure_open(uri),
            {:ok, entries} <- Indexer.Quoted.index_with_cleanup(analysis) do
         {:ok, document.path, entries}
       else
@@ -64,6 +63,20 @@ defmodule Engine.Commands.Reindex do
           error
       end
     end
+
+    defp ensure_open(uri) do
+      case Document.Store.fetch(uri, :analysis) do
+        {:ok, %Document{} = document, analysis} ->
+          {:ok, document, analysis}
+
+        {:error, :not_open} ->
+          # Sometimes, some operations are received long after the reindex is triggered,
+          # such as new files after a batch rename
+          with {:ok, _} <- Document.Store.open_temporary(uri) do
+            Document.Store.fetch(uri, :analysis)
+          end
+      end
+    end
   end
 
   @moduledoc """

apps/engine/lib/engine/commands/rename.ex

@@ -145,6 +145,11 @@ defmodule Engine.Commands.Rename do
         on_update_progress,
         on_complete
       ) do
+    Logger.info(
+      "Starting rename tracking: #{map_size(uri_to_expected_operation)} operations, " <>
+        "#{length(paths_to_reindex)} to reindex, #{length(paths_to_delete)} to delete"
+    )
+
     state =
       State.new(
         uri_to_expected_operation,

apps/expert/lib/expert/engine_api.ex

@@ -171,9 +171,18 @@ defmodule Expert.EngineApi do
 
   This should be called when files are changed or saved during a rename operation.
   The message is used to track which file operations have been completed.
+
+  This function is intentionally fire-and-forget - failures don't affect
+  the main document change/save flow.
   """
   def maybe_update_rename_progress(%Project{} = project, message) do
-    call(project, Engine, :maybe_update_rename_progress, [message])
+    try do
+      call(project, Engine, :maybe_update_rename_progress, [message])
+    rescue
+      _ -> {:error, :not_in_rename_progress}
+    catch
+      :exit, _ -> {:error, :not_in_rename_progress}
+    end
   end
 
   defdelegate stop(project), to: EngineNode