lib: fix readdir in recursive mode with a buffer argument

calling readdir with a buffer arguemnt and the recursive flag produces an ERR_INVALID_ARG_TYPE error. This is to fix that. Fixes: #58892
nodejs · y-okt · Dec 2, 2025 · Dec 8, 2025 · Dec 13, 2025 · Dec 13, 2025
commit bb1084faef40b6556a3b1e6fb2d806d3d1a0d490
diff --git a/lib/fs.js b/lib/fs.js
@@ -1394,6 +1394,31 @@ function readdirRecursive(basePath, options, callback) {
   read(context.pathsQueue[i++]);
 }
 
+function joinPath(base, name) {
+  if (BufferIsBuffer(base)) {
+    const baseStr = BufferToString(base);
+    const nameStr = BufferIsBuffer(name) ? BufferToString(name) : name;
+    return Buffer.from(pathModule.join(baseStr, nameStr));
+  }
+  return pathModule.join(base, name);
+}
+
+function relativePath(from, to) {
+  if (BufferIsBuffer(from)) {
+    const fromStr = BufferToString(from);
+    const toStr = BufferIsBuffer(to) ? BufferToString(to) : to;
+    return Buffer.from(pathModule.relative(fromStr, toStr));
+  }
+  return pathModule.relative(from, to);
+}
+
+function toPathString(path) {
+  if (BufferIsBuffer(path)) {
+    return BufferToString(path);
+  }
+  return path;
+}
+
 // Calling `readdir` with `withFileTypes=true`, the result is an array of arrays.
 // The first array is the names, and the second array is the types.
 // They are guaranteed to be the same length; hence, setting `length` to the length
@@ -1407,21 +1432,21 @@ function handleDirents({ result, currentPath, context }) {
   for (let i = 0; i < length; i++) {
     // Avoid excluding symlinks, as they are not directories.
     // Refs: https://github.com/nodejs/node/issues/52663
-    const fullPath = pathModule.join(currentPath, names[i]);
+    const fullPath = joinPath(currentPath, names[i]);
     const dirent = getDirent(currentPath, names[i], types[i]);
     ArrayPrototypePush(context.readdirResults, dirent);
 
-    if (dirent.isDirectory() || binding.internalModuleStat(fullPath) === 1) {
+    if (dirent.isDirectory() || binding.internalModuleStat(toPathString(fullPath)) === 1) {
       ArrayPrototypePush(context.pathsQueue, fullPath);
     }
   }
 }
 
 function handleFilePaths({ result, currentPath, context }) {
   for (let i = 0; i < result.length; i++) {
-    const resultPath = pathModule.join(currentPath, result[i]);
-    const relativeResultPath = pathModule.relative(context.basePath, resultPath);
-    const stat = binding.internalModuleStat(resultPath);
+    const resultPath = joinPath(currentPath, result[i]);
+    const relativeResultPath = relativePath(context.basePath, resultPath);
+    const stat = binding.internalModuleStat(toPathString(resultPath));
     ArrayPrototypePush(context.readdirResults, relativeResultPath);
 
     if (stat === 1) {

diff --git a/lib/internal/fs/promises.js b/lib/internal/fs/promises.js
@@ -870,6 +870,31 @@ async function mkdir(path, options) {
   );
 }
 
+function joinPath(base, name) {
+  if (BufferIsBuffer(base)) {
+    const baseStr = BufferToString(base);
+    const nameStr = BufferIsBuffer(name) ? BufferToString(name) : name;
+    return Buffer.from(pathModule.join(baseStr, nameStr));
+  }
+  return pathModule.join(base, name);
+}
+
+function relativePath(from, to) {
+  if (BufferIsBuffer(from)) {
+    const fromStr = BufferToString(from);
+    const toStr = BufferIsBuffer(to) ? BufferToString(to) : to;
+    return Buffer.from(pathModule.relative(fromStr, toStr));
+  }
+  return pathModule.relative(from, to);
+}
+
+function toPathString(path) {
+  if (BufferIsBuffer(path)) {
+    return BufferToString(path);
+  }
+  return path;
+}
+
 async function readdirRecursive(originalPath, options) {
   const result = [];
   const queue = [
@@ -896,7 +921,7 @@ async function readdirRecursive(originalPath, options) {
       for (const dirent of getDirents(path, readdir)) {
         ArrayPrototypePush(result, dirent);
         if (dirent.isDirectory()) {
-          const direntPath = pathModule.join(path, dirent.name);
+          const direntPath = joinPath(path, dirent.name);
           ArrayPrototypePush(queue, [
             direntPath,
             await PromisePrototypeThen(
@@ -917,11 +942,11 @@ async function readdirRecursive(originalPath, options) {
     while (queue.length > 0) {
       const { 0: path, 1: readdir } = ArrayPrototypePop(queue);
       for (const ent of readdir) {
-        const direntPath = pathModule.join(path, ent);
-        const stat = binding.internalModuleStat(direntPath);
+        const direntPath = joinPath(path, ent);
+        const stat = binding.internalModuleStat(toPathString(direntPath));
         ArrayPrototypePush(
           result,
-          pathModule.relative(originalPath, direntPath),
+          relativePath(originalPath, direntPath),
         );
         if (stat === 1) {
           ArrayPrototypePush(queue, [

diff --git a/...-readdir-promise-recursive-with-buffer.js → ...-readdir-promise-recursive-with-buffer.js b/...-readdir-promise-recursive-with-buffer.js → ...-readdir-promise-recursive-with-buffer.js
@@ -1,9 +1,6 @@
 'use strict';
 
-// This test will fail because the the implementation does not properly
-// handle the case when the path is a Buffer and the function is called
-// in recursive mode.
-
+// Test that fs.promises.readdir works with Buffer paths in recursive mode.
 // Refs: https://github.com/nodejs/node/issues/58892
 
 const common = require('../common');

diff --git a/.../test-fs-readdir-recursive-with-buffer.js → .../test-fs-readdir-recursive-with-buffer.js b/.../test-fs-readdir-recursive-with-buffer.js → .../test-fs-readdir-recursive-with-buffer.js
@@ -1,9 +1,6 @@
 'use strict';
 
-// This test will fail because the the implementation does not properly
-// handle the case when the path is a Buffer and the function is called
-// in recursive mode.
-
+// Test that readdir callback works with Buffer paths in recursive mode.
 // Refs: https://github.com/nodejs/node/issues/58892
 
 const common = require('../common');

diff --git a/...-fs-readdir-sync-recursive-with-buffer.js → ...-fs-readdir-sync-recursive-with-buffer.js b/...-fs-readdir-sync-recursive-with-buffer.js → ...-fs-readdir-sync-recursive-with-buffer.js
@@ -1,9 +1,6 @@
 'use strict';
 
-// This test will fail because the the implementation does not properly
-// handle the case when the path is a Buffer and the function is called
-// in recursive mode.
-
+// Test that readdirSync works with Buffer paths in recursive mode.
 // Refs: https://github.com/nodejs/node/issues/58892
 
 require('../common');