fix: fix bug on utimes, futimes, add support of lutimes

lutimes is available on Nodejs v14.5.0+ and v12.19.0, our CI matrix
covers both versions.

closes #365

Author: 3cp

lib/binding.js

@@ -7,7 +7,7 @@ const Directory = require('./directory.js');
 const SymbolicLink = require('./symlink.js');
 const {FSError} = require('./error.js');
 const constants = require('constants');
-const getPathParts = require('./filesystem.js').getPathParts;
+const {getPathParts, getRealPath} = require('./filesystem.js');
 
 const MODE_TO_KTYPE = {
   [constants.S_IFREG]: constants.UV_DIRENT_FILE,
@@ -260,10 +260,8 @@ Binding.prototype.realpath = function (filepath, encoding, callback, ctx) {
       throw new FSError('ENOENT', filepath);
     }
 
-    if (process.platform === 'win32' && realPath.startsWith('\\\\?\\')) {
-      // Remove win32 file namespace prefix \\?\
-      realPath = realPath.slice(4);
-    }
+    // Remove win32 file namespace prefix \\?\
+    realPath = getRealPath(realPath);
 
     if (encoding === 'buffer') {
       realPath = Buffer.from(realPath);
@@ -1073,12 +1071,45 @@ Binding.prototype.unlink = function (pathname, callback, ctx) {
 Binding.prototype.utimes = function (pathname, atime, mtime, callback, ctx) {
   markSyscall(ctx, 'utimes');
 
+  return maybeCallback(normalizeCallback(callback), ctx, this, function () {
+    let filepath = deBuffer(pathname);
+    let item = this._system.getItem(filepath);
+    let links = 0;
+    while (item instanceof SymbolicLink) {
+      if (links > MAX_LINKS) {
+        throw new FSError('ELOOP', filepath);
+      }
+      filepath = path.resolve(path.dirname(filepath), item.getPath());
+      item = this._system.getItem(filepath);
+      ++links;
+    }
+    if (!item) {
+      throw new FSError('ENOENT', pathname);
+    }
+    item.setATime(new Date(atime * 1000));
+    item.setMTime(new Date(mtime * 1000));
+  });
+};
+
+/**
+ * Update timestamps.
+ * @param {string} pathname Path to item.
+ * @param {number} atime Access time (in seconds).
+ * @param {number} mtime Modification time (in seconds).
+ * @param {function(Error)} callback Optional callback.
+ * @param {object} ctx Context object (optional), only for nodejs v10+.
+ * @return {*} The return if no callback is provided.
+ */
+Binding.prototype.lutimes = function (pathname, atime, mtime, callback, ctx) {
+  markSyscall(ctx, 'utimes');
+
   return maybeCallback(normalizeCallback(callback), ctx, this, function () {
     pathname = deBuffer(pathname);
     const item = this._system.getItem(pathname);
     if (!item) {
       throw new FSError('ENOENT', pathname);
     }
+    // lutimes doesn't follow symlink
     item.setATime(new Date(atime * 1000));
     item.setMTime(new Date(mtime * 1000));
   });
@@ -1098,7 +1129,17 @@ Binding.prototype.futimes = function (fd, atime, mtime, callback, ctx) {
 
   return maybeCallback(normalizeCallback(callback), ctx, this, function () {
     const descriptor = this.getDescriptorById(fd);
-    const item = descriptor.getItem();
+    let item = descriptor.getItem();
+    let filepath = this._system.getFilepath(item);
+    let links = 0;
+    while (item instanceof SymbolicLink) {
+      if (links > MAX_LINKS) {
+        throw new FSError('ELOOP', filepath);
+      }
+      filepath = path.resolve(path.dirname(filepath), item.getPath());
+      item = this._system.getItem(filepath);
+      ++links;
+    }
     item.setATime(new Date(atime * 1000));
     item.setMTime(new Date(mtime * 1000));
   });

lib/filesystem.js

@@ -9,19 +9,26 @@ const SymbolicLink = require('./symlink.js');
 
 const isWindows = process.platform === 'win32';
 
-function toNamespacedPath(filePath) {
-  return path.toNamespacedPath
-    ? path.toNamespacedPath(filePath)
-    : path._makeLong(filePath);
+// on Win32, change filepath from \\?\c:\a\b to C:\a\b
+function getRealPath(filepath) {
+  if (isWindows && filepath.startsWith('\\\\?\\')) {
+    // Remove win32 file namespace prefix \\?\
+    return filepath[4].toUpperCase() + filepath.slice(5);
+  }
+  return filepath;
 }
 
 function getPathParts(filepath) {
-  const parts = toNamespacedPath(path.resolve(filepath)).split(path.sep);
+  // path.toNamespacedPath is only for Win32 system.
+  // on other platform, it returns the path unmodified.
+  const parts = path.toNamespacedPath(path.resolve(filepath)).split(path.sep);
   parts.shift();
   if (isWindows) {
     // parts currently looks like ['', '?', 'c:', ...]
     parts.shift();
     const q = parts.shift(); // should be '?'
+    // https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file?redirectedfrom=MSDN#win32-file-namespaces
+    // Win32 File Namespaces prefix \\?\
     const base = '\\\\' + q + '\\' + parts.shift().toLowerCase();
     parts.unshift(base);
   }
@@ -130,6 +137,35 @@ FileSystem.prototype.getItem = function (filepath) {
   return item;
 };
 
+function _getFilepath(item, itemPath, wanted) {
+  if (item === wanted) {
+    return itemPath;
+  }
+  if (item instanceof Directory) {
+    for (const name of item.list()) {
+      const got = _getFilepath(
+        item.getItem(name),
+        path.join(itemPath, name),
+        wanted
+      );
+      if (got) {
+        return got;
+      }
+    }
+  }
+  return null;
+}
+
+/**
+ * Get file path from a file system item.
+ * @param {Item} item a file system item.
+ * @return {string} file path for the item (or null if not found).
+ */
+FileSystem.prototype.getFilepath = function (item) {
+  const namespacedPath = _getFilepath(this._root, isWindows ? '' : '/', item);
+  return getRealPath(namespacedPath);
+};
+
 /**
  * Populate a directory with an item.
  * @param {Directory} directory The directory to populate.
@@ -329,4 +365,4 @@ FileSystem.directory = function (config) {
 module.exports = FileSystem;
 exports = module.exports;
 exports.getPathParts = getPathParts;
-exports.toNamespacedPath = toNamespacedPath;
+exports.getRealPath = getRealPath;

lib/index.js

@@ -13,8 +13,6 @@ const {
 } = require('./readfilecontext.js');
 const fs = require('fs');
 
-const toNamespacedPath = FileSystem.toNamespacedPath;
-
 const realProcessProps = {
   cwd: process.cwd,
   chdir: process.chdir,
@@ -153,7 +151,7 @@ module.exports = function mock(config, options = {}) {
     },
     function chdir(directory) {
       if (realBinding._mockedBinding) {
-        if (!fs.statSync(toNamespacedPath(directory)).isDirectory()) {
+        if (!fs.statSync(path.toNamespacedPath(directory)).isDirectory()) {
           throw new FSError('ENOTDIR');
         }
         currentPath = path.resolve(currentPath, directory);

test/lib/filesystem.spec.js

@@ -40,7 +40,7 @@ describe('FileSystem', function () {
     });
   });
 
-  describe('#getItem()', function () {
+  describe('#getItem() #getFilepath()', function () {
     it('gets an item', function () {
       const system = FileSystem.create({
         'one/two/three.js': 'contents',
@@ -49,6 +49,7 @@ describe('FileSystem', function () {
       const filepath = path.join('one', 'two', 'three.js');
       const item = system.getItem(filepath);
       assert.instanceOf(item, File);
+      assert.equal(system.getFilepath(item), path.resolve(filepath));
     });
 
     it('returns null if not found', function () {
@@ -79,10 +80,18 @@ describe('FileSystem', function () {
       });
       const file = system.getItem(path.join('dir-link', 'a'));
       assert.instanceOf(file, File);
+      assert.equal(
+        system.getFilepath(file),
+        path.resolve(path.join('b', 'c', 'dir', 'a'))
+      );
 
       const dir = system.getItem(path.join('dir-link', 'b'));
       assert.instanceOf(dir, Directory);
       assert.deepEqual(dir.list().sort(), ['c', 'd']);
+      assert.equal(
+        system.getFilepath(dir),
+        path.resolve(path.join('b', 'c', 'dir', 'b'))
+      );
     });
   });
 });