perf: skip redundant filesystem probes during discovery and load path rewriting

.changeset/cut-discovery-fs-probes.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/intent': patch
+---
+
+Skip redundant filesystem probes when scanning packages and rewriting skill load paths during `intent list` and `intent load`; behavior does not change.

packages/intent/src/discovery/register.ts

@@ -42,10 +42,12 @@ export interface CreatePackageRegistrarOptions {
 
 export function createPackageRegistrar(opts: CreatePackageRegistrarOptions) {
   const attemptedPackageRoots = new Set<string>()
+  const attemptedRawDirs = new Set<string>()
   const scannedNodeModulesDirs = new Set<string>()
 
   function shouldAttemptPackageRoot(dirPath: string): boolean {
     const key = opts.getFsIdentity(dirPath)
+    attemptedRawDirs.add(key)
     if (attemptedPackageRoots.has(key)) return false
     attemptedPackageRoots.add(key)
     return true
@@ -80,11 +82,14 @@ export function createPackageRegistrar(opts: CreatePackageRegistrarOptions) {
     fallbackName: string,
     source: IntentPackage['source'] = 'local',
   ): boolean {
-    if (!shouldAttemptPackageRoot(dirPath)) return false
+    if (attemptedRawDirs.has(dirPath)) return false
+    attemptedRawDirs.add(dirPath)
 
     const skillsDir = join(dirPath, 'skills')
     if (!opts.exists(skillsDir)) return false
 
+    if (!shouldAttemptPackageRoot(dirPath)) return false
+
     const pkgJson = opts.readPkgJson(dirPath)
     if (!pkgJson) {
       opts.warnings.push(`Could not read package.json for ${dirPath}`)

packages/intent/src/discovery/scanner.ts

@@ -624,6 +624,10 @@ function createPackageKindResolver(
   workspacePackageKeys: Set<string>,
   getFsIdentity: (path: string) => string,
 ): (packageRoot: string) => IntentPackage['kind'] {
+  if (workspacePackageKeys.size === 0) {
+    return () => 'npm'
+  }
+
   return (packageRoot: string): IntentPackage['kind'] => {
     return workspacePackageKeys.has(getFsIdentity(packageRoot))
       ? 'workspace'

packages/intent/src/skills/paths.ts

@@ -50,9 +50,11 @@ export function rewriteSkillLoadPaths({
   projectRoot: string
   skills: Array<SkillEntry>
 }): void {
+  const topLevelPackageRoot =
+    packageName !== '' ? join(projectRoot, 'node_modules', packageName) : ''
   const hasStableSymlink =
-    packageName !== '' &&
-    existsSync(join(projectRoot, 'node_modules', packageName))
+    topLevelPackageRoot !== '' &&
+    (packageRoot === topLevelPackageRoot || existsSync(topLevelPackageRoot))
 
   for (const skill of skills) {
     if (hasStableSymlink) {

packages/intent/tests/repeated-work.test.ts

@@ -1,5 +1,6 @@
 import { execFileSync } from 'node:child_process'
 import {
+  existsSync,
   lstatSync,
   mkdirSync,
   mkdtempSync,
@@ -30,6 +31,7 @@ vi.mock('node:fs', async (importOriginal) => {
   const fs = await importOriginal<typeof NodeFs>()
   return {
     ...fs,
+    existsSync: vi.fn(fs.existsSync),
     readFileSync: vi.fn(fs.readFileSync),
     readdirSync: vi.fn(fs.readdirSync),
     lstatSync: vi.fn(fs.lstatSync),
@@ -91,12 +93,41 @@ describe('command work budgets', () => {
     expect(resolveIntentSkill('example#core', { cwd: root }).skillName).toBe(
       'core',
     )
+    expect(
+      vi
+        .mocked(existsSync)
+        .mock.calls.filter(
+          ([path]) => path === join(root, 'node_modules', 'example'),
+        ),
+    ).toHaveLength(0)
     expect(loadIntentSkill('example#core', { cwd: root }).content).toContain(
       'Guide.',
     )
     expect(metadataRead).not.toHaveBeenCalled()
   })
 
+  it('skips lstat on node_modules packages without a skills directory during list', () => {
+    write(
+      join(root, 'package.json'),
+      JSON.stringify({
+        name: 'consumer',
+        dependencies: { example: '1.0.0', plain: '1.0.0' },
+      }),
+    )
+    writePackage(join(root, 'node_modules', 'example'), 'example')
+    const plainDir = join(root, 'node_modules', 'plain')
+    write(
+      join(plainDir, 'package.json'),
+      JSON.stringify({ name: 'plain', version: '1.0.0' }),
+    )
+    vi.clearAllMocks()
+
+    expect(listIntentSkills({ cwd: root }).skills).toHaveLength(1)
+    expect(
+      vi.mocked(lstatSync).mock.calls.filter(([path]) => path === plainDir),
+    ).toHaveLength(0)
+  })
+
   it('indexes each skill path once when matching many artifact entries by name', async () => {
     write(
       join(root, 'package.json'),