⚡ Bolt: Optimize collection processing in computed properties

.jules/bolt.md

@@ -28,3 +28,7 @@
 ## 2025-10-24 - Bulk Disk I/O Parallelization and Thread Pool Starvation
 **Learning:** Both `withTaskGroup` and `Task.detached` schedule their work on Swift's cooperative thread pool, which has only as many threads as the CPU has cores. Running synchronous blocking I/O (like `FileManager.removeItem`) directly inside such tasks ties up cooperative threads — when every thread is parked in a syscall there is nothing left to advance other Swift Concurrency work, which manifests as starvation and (with self-referential `await` chains) outright deadlock. `Task.detached` does not help here: "detached" means unstructured/independent, not "off the cooperative pool."
 **Action:** To parallelize bulk blocking I/O, combine a sliding-window `withThrowingTaskGroup` (e.g., `maxConcurrency` of 8) with a per-item handoff to a GCD queue: wrap the blocking call in `withCheckedThrowingContinuation` and dispatch it via `DispatchQueue.global(qos: .userInitiated).async { ... continuation.resume(...) }`. The cooperative-pool task only `await`s the continuation, so it never holds a thread while the syscall runs.
+
+## 2024-05-24 - Short-circuiting Computed Properties
+**Learning:** In SwiftUI view models, checking if a filtered array is empty (`!array.filter { ... }.isEmpty`) or computing a full reduction (`array.lazy.filter { ... }.reduce(0, +) > 0`) to determine a simple boolean state causes unnecessary O(N) traversal and intermediate array allocation on every UI render cycle.
+**Action:** Use `.contains(where: { ... })` to short-circuit evaluation. It stops iterating as soon as a match is found (best case O(1)) and avoids allocating intermediate collections.

Sources/Cacheout/ViewModels/CacheoutViewModel.swift

@@ -106,7 +106,8 @@ class CacheoutViewModel: ObservableObject {
     }
 
     var selectedSize: Int64 {
-        selectedResults.reduce(0) { $0 + $1.sizeBytes }
+        // ⚡ Bolt: Use .lazy.filter before .reduce to prevent intermediate array allocation
+        scanResults.lazy.filter(\.isSelected).reduce(0) { $0 + $1.sizeBytes }
     }
 
     var formattedSelectedSize: String {
@@ -118,7 +119,9 @@ class CacheoutViewModel: ObservableObject {
     }
 
     var hasResults: Bool { !scanResults.isEmpty || !nodeModulesItems.isEmpty }
-    var hasSelection: Bool { !selectedResults.isEmpty || selectedNodeModulesSize > 0 }
+
+    // ⚡ Bolt: Use .contains(where:) to short-circuit evaluation instead of checking .isEmpty on a filtered array
+    var hasSelection: Bool { scanResults.contains(where: \.isSelected) || nodeModulesItems.contains(where: \.isSelected) }
 
     // MARK: - Node Modules computed properties