vfs: use path.posix methods instead of custom implementations

Author: mcollina

lib/internal/vfs/providers/memory.js

@@ -8,6 +8,7 @@ const {
 } = primordials;
 
 const { Buffer } = require('buffer');
+const { posix: pathPosix } = require('path');
 const { VirtualProvider } = require('internal/vfs/provider');
 const { MemoryFileHandle } = require('internal/vfs/file_handle');
 const {
@@ -169,27 +170,14 @@ class MemoryProvider extends VirtualProvider {
    * @returns {string} Normalized path
    */
   _normalizePath(path) {
-    // Normalize slashes
+    // Convert backslashes to forward slashes
     let normalized = path.replace(/\\/g, '/');
+    // Ensure absolute path
     if (!normalized.startsWith('/')) {
       normalized = '/' + normalized;
     }
-
-    // Split into segments and resolve . and ..
-    const segments = normalized.split('/').filter((s) => s !== '' && s !== '.');
-    const resolved = [];
-    for (const segment of segments) {
-      if (segment === '..') {
-        // Go up one level (but don't go above root)
-        if (resolved.length > 0) {
-          resolved.pop();
-        }
-      } else {
-        resolved.push(segment);
-      }
-    }
-
-    return '/' + resolved.join('/');
+    // Use path.posix.normalize to resolve . and ..
+    return pathPosix.normalize(normalized);
   }
 
   /**
@@ -213,11 +201,7 @@ class MemoryProvider extends VirtualProvider {
     if (path === '/') {
       return null;
     }
-    const lastSlash = path.lastIndexOf('/');
-    if (lastSlash === 0) {
-      return '/';
-    }
-    return path.slice(0, lastSlash);
+    return pathPosix.dirname(path);
   }
 
   /**
@@ -226,8 +210,7 @@ class MemoryProvider extends VirtualProvider {
    * @returns {string} Base name
    */
   _getBaseName(path) {
-    const lastSlash = path.lastIndexOf('/');
-    return path.slice(lastSlash + 1);
+    return pathPosix.basename(path);
   }
 
   /**
@@ -241,11 +224,8 @@ class MemoryProvider extends VirtualProvider {
       return this._normalizePath(target);
     }
     // Relative target: resolve against symlink's parent directory
-    const parentPath = this._getParentPath(symlinkPath);
-    if (parentPath === null) {
-      return this._normalizePath('/' + target);
-    }
-    return this._normalizePath(parentPath + '/' + target);
+    const parentPath = this._getParentPath(symlinkPath) || '/';
+    return this._normalizePath(pathPosix.join(parentPath, target));
   }
 
   /**
@@ -264,7 +244,7 @@ class MemoryProvider extends VirtualProvider {
 
     const segments = this._splitPath(normalized);
     let current = this[kRoot];
-    let currentPath = '';
+    let currentPath = '/';
 
     for (let i = 0; i < segments.length; i++) {
       const segment = segments[i];
@@ -291,14 +271,14 @@ class MemoryProvider extends VirtualProvider {
       }
 
       // Ensure directory is populated before accessing children
-      this._ensurePopulated(current, currentPath || '/');
+      this._ensurePopulated(current, currentPath);
 
       const entry = current.children.get(segment);
       if (!entry) {
         return { entry: null, resolvedPath: null };
       }
 
-      currentPath = currentPath + '/' + segment;
+      currentPath = pathPosix.join(currentPath, segment);
       current = entry;
     }
 
@@ -353,7 +333,7 @@ class MemoryProvider extends VirtualProvider {
 
       // Follow symlinks in parent path
       if (current.isSymbolicLink()) {
-        const currentPath = '/' + segments.slice(0, i).join('/');
+        const currentPath = pathPosix.join('/', ...segments.slice(0, i));
         const targetPath = this._resolveSymlinkTarget(currentPath, current.target);
         const result = this._lookupEntry(targetPath, true, 0);
         if (!result.entry) {
@@ -367,8 +347,8 @@ class MemoryProvider extends VirtualProvider {
       }
 
       // Ensure directory is populated before accessing children
-      const currentPath = '/' + segments.slice(0, i).join('/');
-      this._ensurePopulated(current, currentPath || '/');
+      const currentPath = pathPosix.join('/', ...segments.slice(0, i));
+      this._ensurePopulated(current, currentPath);
 
       let entry = current.children.get(segment);
       if (!entry) {
@@ -388,7 +368,7 @@ class MemoryProvider extends VirtualProvider {
     }
 
     // Ensure final directory is populated
-    const finalPath = '/' + segments.join('/');
+    const finalPath = pathPosix.join('/', ...segments);
     this._ensurePopulated(current, finalPath);
 
     return current;
@@ -578,10 +558,10 @@ class MemoryProvider extends VirtualProvider {
       // Create all parent directories
       const segments = this._splitPath(normalized);
       let current = this[kRoot];
-      let currentPath = '';
+      let currentPath = '/';
 
       for (const segment of segments) {
-        currentPath = currentPath + '/' + segment;
+        currentPath = pathPosix.join(currentPath, segment);
         let entry = current.children.get(segment);
         if (!entry) {
           entry = new MemoryEntry(TYPE_DIR, { mode: options?.mode });

lib/internal/vfs/providers/sea.js

@@ -11,6 +11,7 @@ const {
 } = primordials;
 
 const { Buffer } = require('buffer');
+const { posix: pathPosix } = require('path');
 const { VirtualProvider } = require('internal/vfs/provider');
 const { VirtualFileHandle } = require('internal/vfs/file_handle');
 const {
@@ -168,10 +169,10 @@ class SEAProvider extends VirtualProvider {
 
       // Derive parent directories
       const parts = path.split('/').filter(Boolean);
-      let currentPath = '';
+      let currentPath = '/';
       for (let j = 0; j < parts.length - 1; j++) {
-        const parentPath = currentPath || '/';
-        currentPath = currentPath + '/' + parts[j];
+        const parentPath = currentPath;
+        currentPath = pathPosix.join(currentPath, parts[j]);
 
         if (!this[kDirectories].has(currentPath)) {
           this[kDirectories].set(currentPath, new SafeSet());
@@ -186,8 +187,8 @@ class SEAProvider extends VirtualProvider {
 
       // Add file to parent directory's children
       if (parts.length > 0) {
-        const fileName = parts[parts.length - 1];
-        const parentPath = parts.length === 1 ? '/' : '/' + parts.slice(0, -1).join('/');
+        const fileName = pathPosix.basename(path);
+        const parentPath = pathPosix.dirname(path);
 
         if (!this[kDirectories].has(parentPath)) {
           this[kDirectories].set(parentPath, new SafeSet());
@@ -212,14 +213,14 @@ class SEAProvider extends VirtualProvider {
    * @returns {string} Normalized path
    */
   _normalizePath(path) {
+    // Convert backslashes to forward slashes
     let normalized = path.replace(/\\/g, '/');
-    if (normalized !== '/' && normalized.endsWith('/')) {
-      normalized = normalized.slice(0, -1);
-    }
+    // Ensure absolute path
     if (!normalized.startsWith('/')) {
       normalized = '/' + normalized;
     }
-    return normalized;
+    // Use path.posix.normalize to resolve . and .. and remove trailing slashes
+    return pathPosix.normalize(normalized);
   }
 
   /**

lib/internal/vfs/router.js

@@ -2,14 +2,13 @@
 
 const {
   StringPrototypeEndsWith,
-  StringPrototypeLastIndexOf,
   StringPrototypeReplaceAll,
   StringPrototypeSlice,
   StringPrototypeSplit,
   StringPrototypeStartsWith,
 } = primordials;
 
-const { basename, isAbsolute, resolve, sep } = require('path');
+const { isAbsolute, posix: pathPosix, resolve, sep } = require('path');
 
 /**
  * Normalizes a path for VFS lookup.
@@ -60,11 +59,7 @@ function getParentPath(normalizedPath) {
   if (normalizedPath === '/') {
     return null;
   }
-  const lastSlash = StringPrototypeLastIndexOf(normalizedPath, '/');
-  if (lastSlash === 0) {
-    return '/';
-  }
-  return StringPrototypeSlice(normalizedPath, 0, lastSlash);
+  return pathPosix.dirname(normalizedPath);
 }
 
 /**
@@ -73,8 +68,7 @@ function getParentPath(normalizedPath) {
  * @returns {string} The base name
  */
 function getBaseName(normalizedPath) {
-  // Basename works correctly for VFS paths since they use forward slashes
-  return basename(normalizedPath);
+  return pathPosix.basename(normalizedPath);
 }
 
 /**