From 37d504b044bb126dad6ac98c980a1433406b922b Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon, 4 May 2026 03:46:09 +0000
Subject: [PATCH] Fix TaskGroup serialization in NodeModulesScanner

Added the `nonisolated` keyword to `findNodeModules` and `directorySize` in `NodeModulesScanner` to prevent execution serialization on the actor's executor. This allows these computationally intensive methods to run truly concurrently on the global cooperative thread pool when invoked from within a TaskGroup.

Co-authored-by: acebytes <2820910+acebytes@users.noreply.github.com>
---
 .jules/bolt.md                                    | 3 +++
 Sources/Cacheout/Scanner/NodeModulesScanner.swift | 6 ++++--
 2 files changed, 7 insertions(+), 2 deletions(-)
 create mode 100644 .jules/bolt.md

diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..5ad3160
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-04 - TaskGroup Serialization in Actors
+**Learning:** In Swift Concurrency, when an actor creates a `TaskGroup` and its subtasks call an `isolated` method on the same actor, execution is serialized on the actor's executor, destroying parallelism.
+**Action:** Mark computationally intensive or state-independent methods called from `TaskGroup` subtasks as `nonisolated` (like `NodeModulesScanner.findNodeModules`) so they run concurrently on the global pool.
diff --git a/Sources/Cacheout/Scanner/NodeModulesScanner.swift b/Sources/Cacheout/Scanner/NodeModulesScanner.swift
index 3ed4d8c..0306f0e 100644
--- a/Sources/Cacheout/Scanner/NodeModulesScanner.swift
+++ b/Sources/Cacheout/Scanner/NodeModulesScanner.swift
@@ -77,7 +77,8 @@ actor NodeModulesScanner {
             .sorted { $0.sizeBytes > $1.sizeBytes }
     }
 
-    private func findNodeModules(in directory: URL, maxDepth: Int, currentDepth: Int = 0) async -> [NodeModulesItem] {
+    nonisolated private func findNodeModules(in directory: URL, maxDepth: Int, currentDepth: Int = 0) async -> [NodeModulesItem] {
+        let fileManager = FileManager.default
         guard currentDepth < maxDepth else { return [] }
 
         var results: [NodeModulesItem] = []
@@ -120,7 +121,8 @@ actor NodeModulesScanner {
         return results
     }
 
-    private func directorySize(at url: URL) -> Int64 {
+    nonisolated private func directorySize(at url: URL) -> Int64 {
+        let fileManager = FileManager.default
         var total: Int64 = 0
         guard let enumerator = fileManager.enumerator(
             at: url,