perf: cache the resolved cloakbrowser version instead of re-reading it per status call

src/browser/runtime/local-cloak/cloak-version.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it, vi } from 'vitest';
+
+// Isolated file: the version cache is module-level and populated by the first
+// call in the process, so this must import a fresh copy to observe the read.
+describe('resolveCloakBrowserVersion', () => {
+  it('resolves and reads cloakbrowser/package.json only once per process', async () => {
+    vi.resetModules();
+    const fs = (await import('node:fs')).default;
+    // Import before spying: loading the module graph reads files of its own,
+    // and only reads made by resolveCloakBrowserVersion should be counted.
+    const { resolveCloakBrowserVersion } = await import('./session-manager.js');
+    const readFileSync = vi.spyOn(fs, 'readFileSync');
+    try {
+      const first = resolveCloakBrowserVersion();
+      const second = resolveCloakBrowserVersion();
+      const third = resolveCloakBrowserVersion();
+
+      expect(second).toBe(first);
+      expect(third).toBe(first);
+      expect(readFileSync).toHaveBeenCalledTimes(1);
+    } finally {
+      readFileSync.mockRestore();
+    }
+  });
+});

src/browser/runtime/local-cloak/session-manager.ts

@@ -10,15 +10,28 @@ import { normalizeProfileId, resolveCloakProfileDir } from './profiles.js';
 import { CloakNetworkCapture } from './network.js';
 import { findPackageRoot } from '../../../package-paths.js';
 
-/** Installed `cloakbrowser` npm package version, for doctor/status display. */
+const UNRESOLVED = Symbol('unresolved');
+let cachedCloakBrowserVersion: string | undefined | typeof UNRESOLVED = UNRESOLVED;
+
+/**
+ * Installed `cloakbrowser` npm package version, for doctor/status display.
+ *
+ * Resolved once per process. The version cannot change while we are running, and
+ * `profileStatuses()` calls this per profile, so an uncached read meant N+1
+ * synchronous resolve-read-parse cycles on every status poll. The sentinel keeps
+ * a genuine `undefined` (the catch path) cached too, so an unresolvable
+ * `cloakbrowser` is not retried on every call.
+ */
 export function resolveCloakBrowserVersion(): string | undefined {
+  if (cachedCloakBrowserVersion !== UNRESOLVED) return cachedCloakBrowserVersion;
   try {
     const entryPath = fileURLToPath(import.meta.resolve('cloakbrowser'));
-    const pkg = JSON.parse(fs.readFileSync(path.join(findPackageRoot(entryPath), 'package.json'), 'utf-8'));
-    return typeof pkg.version === 'string' ? pkg.version : undefined;
+    const pkg = JSON.parse(fs.readFileSync(path.join(findPackageRoot(entryPath), 'package.json'), 'utf-8')) as { version?: unknown };
+    cachedCloakBrowserVersion = typeof pkg.version === 'string' ? pkg.version : undefined;
   } catch {
-    return undefined;
+    cachedCloakBrowserVersion = undefined;
   }
+  return cachedCloakBrowserVersion;
 }
 
 export type LaunchPersistentContext = typeof cloakLaunchPersistentContext;