From 9753325bc452f2ac6e2f65cccf0806178e105fc2 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 29 Apr 2026 04:17:17 +0000
Subject: [PATCH] Optimize @Published array mutations in CacheoutViewModel

Replaced `for` loop mutations of `@Published` arrays (`scanResults`
and `nodeModulesItems`) with `.map` to batch updates into a single
assignment. Mutating elements of a `@Published` array individually inside
a loop triggers a UI update for every change, causing massive
recalculations (O(N)). This reduces updates to exactly 1 per batch
operation (e.g., when clicking "Select All").

Co-authored-by: acebytes <2820910+acebytes@users.noreply.github.com>
---
 .jules/bolt.md                                |  3 ++
 .../ViewModels/CacheoutViewModel.swift        | 39 +++++++++++++++----
 2 files changed, 34 insertions(+), 8 deletions(-)
 create mode 100644 .jules/bolt.md

diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..ca3e35f
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-20 - Batching @Published Array Mutations
+**Learning:** In SwiftUI ObservableObject view models, mutating individual elements of a @Published array property inside a loop triggers a UI update notification for every change.
+**Action:** Use functional methods like `map` to batch updates into a single property assignment, significantly reducing unnecessary UI recalculations. Always add comments explaining this optimization.
diff --git a/Sources/Cacheout/ViewModels/CacheoutViewModel.swift b/Sources/Cacheout/ViewModels/CacheoutViewModel.swift
index 13a9811..f21d25a 100644
--- a/Sources/Cacheout/ViewModels/CacheoutViewModel.swift
+++ b/Sources/Cacheout/ViewModels/CacheoutViewModel.swift
@@ -172,14 +172,22 @@ class CacheoutViewModel: ObservableObject {
     }
 
     func selectAllSafe() {
-        for i in scanResults.indices where scanResults[i].category.riskLevel == .safe && !scanResults[i].isEmpty {
-            scanResults[i].isSelected = true
+        // Optimization: Batch @Published array update to prevent O(N) UI re-renders
+        scanResults = scanResults.map { result in
+            var copy = result
+            if copy.category.riskLevel == .safe && !copy.isEmpty {
+                copy.isSelected = true
+            }
+            return copy
         }
     }
 
     func deselectAll() {
-        for i in scanResults.indices {
-            scanResults[i].isSelected = false
+        // Optimization: Batch @Published array update to prevent O(N) UI re-renders
+        scanResults = scanResults.map { result in
+            var copy = result
+            copy.isSelected = false
+            return copy
         }
         deselectAllNodeModules()
     }
@@ -193,17 +201,32 @@ class CacheoutViewModel: ObservableObject {
     }
 
     func selectStaleNodeModules() {
-        for i in nodeModulesItems.indices where nodeModulesItems[i].isStale {
-            nodeModulesItems[i].isSelected = true
+        // Optimization: Batch @Published array update to prevent O(N) UI re-renders
+        nodeModulesItems = nodeModulesItems.map { item in
+            var copy = item
+            if copy.isStale {
+                copy.isSelected = true
+            }
+            return copy
         }
     }
 
     func selectAllNodeModules() {
-        for i in nodeModulesItems.indices { nodeModulesItems[i].isSelected = true }
+        // Optimization: Batch @Published array update to prevent O(N) UI re-renders
+        nodeModulesItems = nodeModulesItems.map { item in
+            var copy = item
+            copy.isSelected = true
+            return copy
+        }
     }
 
     func deselectAllNodeModules() {
-        for i in nodeModulesItems.indices { nodeModulesItems[i].isSelected = false }
+        // Optimization: Batch @Published array update to prevent O(N) UI re-renders
+        nodeModulesItems = nodeModulesItems.map { item in
+            var copy = item
+            copy.isSelected = false
+            return copy
+        }
     }
 
     /// Menu bar label: show free GB in the tray