fix: add fs.promises and fs.access/accessSync patches to module hooks

The VFS module hooks only patched synchronous fs methods, leaving async
operations (fs.promises.*, fs.access) unpatched. This caused ENOENT
errors when application code used:
- `await fs.promises.access(path)` (e.g., file existence checks)
- `await fs.promises.readFile(path)` (e.g., loading templates)
- `await fs.promises.stat(path)`, `lstat`, `readdir`, `readlink`, `realpath`
- `fs.accessSync(path)` or `fs.access(path, callback)`

Since `require('fs/promises')` returns the same object as `fs.promises`,
patching directly on `fs.promises` covers both import patterns.

Fixes: #8

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: robertsLando

lib/module_hooks.js

@@ -901,6 +901,124 @@ function installFsPatches() {
     return originalExistsSync.call(fs, path);
   };
 
+  // --- Async callback patches (fs.access, fs.accessSync) ---
+
+  const originalAccessSync = fs.accessSync;
+  fs.accessSync = function accessSync(path, mode) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForExists(path);
+      if (vfsResult !== null) {
+        if (!vfsResult.exists) {
+          throw createENOENT('access', path);
+        }
+        return;
+      }
+    }
+    return originalAccessSync.call(fs, path, mode);
+  };
+
+  const originalAccess = fs.access;
+  fs.access = function access(path, mode, callback) {
+    if (typeof mode === 'function') {
+      callback = mode;
+      mode = fs.constants.F_OK;
+    }
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForExists(path);
+      if (vfsResult !== null) {
+        const err = vfsResult.exists ? null : createENOENT('access', path);
+        if (callback) process.nextTick(callback, err);
+        return;
+      }
+    }
+    return originalAccess.call(fs, path, mode, callback);
+  };
+
+  // --- fs.promises patches ---
+  // Patched directly on the shared object so require('fs/promises') also
+  // picks up the changes (it returns the same reference as fs.promises).
+  // Fixes: https://github.com/platformatic/vfs/issues/8
+
+  const origPAccess = fs.promises.access;
+  fs.promises.access = async function access(path, mode) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForExists(path);
+      if (vfsResult !== null) {
+        if (!vfsResult.exists) {
+          throw createENOENT('access', path);
+        }
+        return;
+      }
+    }
+    return origPAccess.call(fs.promises, path, mode);
+  };
+
+  const origPReadFile = fs.promises.readFile;
+  fs.promises.readFile = async function readFile(path, options) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForRead(path, options);
+      if (vfsResult !== null) {
+        return vfsResult.content;
+      }
+    }
+    return origPReadFile.call(fs.promises, path, options);
+  };
+
+  const origPStat = fs.promises.stat;
+  fs.promises.stat = async function stat(path, options) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForFsStat(path);
+      if (vfsResult !== null) {
+        return vfsResult.stats;
+      }
+    }
+    return origPStat.call(fs.promises, path, options);
+  };
+
+  const origPLstat = fs.promises.lstat;
+  fs.promises.lstat = async function lstat(path, options) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForFsStat(path);
+      if (vfsResult !== null) {
+        return vfsResult.stats;
+      }
+    }
+    return origPLstat.call(fs.promises, path, options);
+  };
+
+  const origPReaddir = fs.promises.readdir;
+  fs.promises.readdir = async function readdir(path, options) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForReaddir(path, options);
+      if (vfsResult !== null) {
+        return vfsResult.entries;
+      }
+    }
+    return origPReaddir.call(fs.promises, path, options);
+  };
+
+  const origPReadlink = fs.promises.readlink;
+  fs.promises.readlink = async function readlink(path, options) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForRealpath(path);
+      if (vfsResult !== null) {
+        return vfsResult.realpath;
+      }
+    }
+    return origPReadlink.call(fs.promises, path, options);
+  };
+
+  const origPRealpath = fs.promises.realpath;
+  fs.promises.realpath = async function realpath(path, options) {
+    if (typeof path === 'string') {
+      const vfsResult = findVFSForRealpath(path);
+      if (vfsResult !== null) {
+        return vfsResult.realpath;
+      }
+    }
+    return origPRealpath.call(fs.promises, path, options);
+  };
+
   originalWatch = fs.watch;
   fs.watch = function watch(filename, options, listener) {
     if (typeof options === 'function') {