vfs: remove addFile and addDirectory methods

Users should use the standard writeFileSync/mkdirSync methods instead.
MockFSContext retains addFile/addDirectory as convenience methods that
prepend the prefix automatically.

Author: mcollina

lib/internal/test_runner/mock/mock.js

@@ -51,7 +51,7 @@ const {
 const { MockTimers } = require('internal/test_runner/mock/mock_timers');
 const { Module } = require('internal/modules/cjs/loader');
 const { _load, _nodeModulePaths, _resolveFilename, isBuiltin } = Module;
-const { join } = require('path');
+const { dirname, join } = require('path');
 
 // Lazy-load VirtualFileSystem to avoid loading VFS code if fs mocking is not used
 const lazyVirtualFileSystem = getLazy(
@@ -432,19 +432,25 @@ class MockFSContext {
 
   /**
    * Adds a file to the mock file system.
-   * @param {string} filePath - The path of the file.
+   * @param {string} filePath - The path of the file (relative to prefix).
    * @param {string|Buffer} content - The file content.
    */
   addFile(filePath, content) {
-    this.vfs.addFile(filePath, content);
+    const fullPath = join(this.prefix, filePath);
+    const parentDir = dirname(fullPath);
+    if (parentDir !== '/') {
+      this.vfs.mkdirSync(parentDir, { __proto__: null, recursive: true });
+    }
+    this.vfs.writeFileSync(fullPath, content);
   }
 
   /**
    * Adds a directory to the mock file system.
-   * @param {string} dirPath - The path of the directory.
+   * @param {string} dirPath - The path of the directory (relative to prefix).
    */
   addDirectory(dirPath) {
-    this.vfs.addDirectory(dirPath);
+    const fullPath = join(this.prefix, dirPath);
+    this.vfs.mkdirSync(fullPath, { __proto__: null, recursive: true });
   }
 
   /**
@@ -812,7 +818,11 @@ class MockTracker {
       for (let i = 0; i < paths.length; i++) {
         const filePath = paths[i];
         const content = files[filePath];
-        vfs.addFile(filePath, content);
+        const parentDir = dirname(filePath);
+        if (parentDir !== '/') {
+          vfs.mkdirSync(parentDir, { __proto__: null, recursive: true });
+        }
+        vfs.writeFileSync(filePath, content);
       }
     }
 

lib/internal/vfs/file_system.js

@@ -460,32 +460,6 @@ class VirtualFileSystem {
     return undefined;
   }
 
-  /**
-   * Adds a file directly to the VFS provider.
-   * This writes directly to the provider bypassing mount point logic,
-   * making it useful for populating the VFS before or after mounting.
-   * @param {string} filePath The file path (relative to VFS root)
-   * @param {Buffer|string} content The file content
-   */
-  addFile(filePath, content) {
-    const { dirname } = require('path');
-    const parentDir = dirname(filePath);
-    if (parentDir !== '/') {
-      this[kProvider].mkdirSync(parentDir, { __proto__: null, recursive: true });
-    }
-    this[kProvider].writeFileSync(filePath, content);
-  }
-
-  /**
-   * Adds a directory directly to the VFS provider.
-   * This writes directly to the provider bypassing mount point logic,
-   * making it useful for populating the VFS before or after mounting.
-   * @param {string} dirPath The directory path (relative to VFS root)
-   */
-  addDirectory(dirPath) {
-    this[kProvider].mkdirSync(dirPath, { __proto__: null, recursive: true });
-  }
-
   /**
    * Removes a directory synchronously.
    * @param {string} dirPath The directory path

test/parallel/test-runner-mock-fs.js

@@ -148,8 +148,8 @@ test('mock.fs() exposes vfs property', (t) => {
   // Access the underlying VFS
   const vfs = mockFs.vfs;
   assert.ok(vfs);
-  assert.strictEqual(typeof vfs.addFile, 'function');
   assert.strictEqual(typeof vfs.readFileSync, 'function');
+  assert.strictEqual(typeof vfs.writeFileSync, 'function');
 
   // Use VFS directly (requires full path including mount point)
   const content = vfs.readFileSync('/vfs-prop-test/file.txt', 'utf8');

test/parallel/test-vfs-watch.js

@@ -143,8 +143,8 @@ const vfs = require('node:vfs');
   }));
 
   setTimeout(() => {
-    // Use addFile to write directly to provider, bypassing mount path logic
-    myVfs.addFile('/data/file.txt', 'updated via fs.watch');
+    // Write to mounted path to trigger watcher
+    myVfs.writeFileSync('/virtual/data/file.txt', 'updated via fs.watch');
   }, 100);
 }
 
@@ -164,8 +164,8 @@ const vfs = require('node:vfs');
   fs.watchFile('/virtual2/data/watchfile.txt', { interval: 50, persistent: false }, listener);
 
   setTimeout(() => {
-    // Use addFile to write directly to provider, bypassing mount path logic
-    myVfs.addFile('/data/watchfile.txt', 'updated via fs.watchFile');
+    // Write to mounted path to trigger watcher
+    myVfs.writeFileSync('/virtual2/data/watchfile.txt', 'updated via fs.watchFile');
   }, 100);
 }
 
@@ -185,8 +185,8 @@ const vfs = require('node:vfs');
   }));
 
   setTimeout(() => {
-    // Use addFile to write directly to provider, bypassing mount path logic
-    myVfs.addFile('/file.txt', 'vfs updated');
+    // Write to mounted path to trigger watcher
+    myVfs.writeFileSync('/overlay-test/file.txt', 'vfs updated');
   }, 100);
 }
 
@@ -282,7 +282,7 @@ const vfs = require('node:vfs');
 
     // Schedule a change
     setTimeout(() => {
-      myVfs.addFile('/promises-test.txt', 'updated');
+      myVfs.writeFileSync('/virtual-promises/promises-test.txt', 'updated');
     }, 100);
 
     // Schedule abort after getting one event
@@ -370,7 +370,7 @@ const vfs = require('node:vfs');
   }));
 
   setTimeout(() => {
-    myVfs.addFile('/data/subdir/nested.txt', 'updated nested');
+    myVfs.writeFileSync('/virtual-recursive/data/subdir/nested.txt', 'updated nested');
   }, 100);
 }