fs: drop readdirRecursiveSync typeof guard, add typings

Always call the native readdirRecursiveSync binding and remove the
unused JS fallback. Document readFileBuffer, writeFileBuffer, and
readdirRecursiveSync on the fs internal binding typings.

Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com>

Author: anonrig

lib/fs.js

@@ -1762,70 +1762,35 @@ function handleFilePaths({ result, currentPath, context }) {
 }
 
 /**
- * An iterative algorithm for reading the entire contents of the `basePath` directory.
- * This function does not validate `basePath` as a directory. It is passed directly to
- * `binding.readdir`.
+ * Reads the entire contents of the `basePath` directory recursively.
+ * This function does not validate `basePath` as a directory. It is passed
+ * directly to `binding.readdirRecursiveSync`.
  * @param {string} basePath
  * @param {{ encoding: string, withFileTypes: boolean }} options
  * @returns {string[] | Dirent[]}
  */
 function readdirSyncRecursive(basePath, options) {
   const withFileTypes = Boolean(options.withFileTypes);
   // C++ walk uses scandir dirent types and avoids per-entry stat() for the
-  // common case (known directory/file types). ~3x faster than the JS walk.
-  if (typeof binding.readdirRecursiveSync === 'function') {
-    const result = binding.readdirRecursiveSync(
-      basePath,
-      options.encoding,
-      withFileTypes,
-    );
-    if (result === undefined) {
-      return;
-    }
-    if (!withFileTypes) {
-      return result;
-    }
-    // result = [names, types, parentPaths]
-    const { 0: names, 1: types, 2: parentPaths } = result;
-    const out = new Array(names.length);
-    for (let i = 0; i < names.length; i++) {
-      out[i] = new Dirent(names[i], types[i], parentPaths[i]);
-    }
-    return out;
-  }
-
-  // Fallback if the native binding is unavailable.
-  const context = {
-    withFileTypes,
-    encoding: options.encoding,
+  // common case (known directory/file types).
+  const result = binding.readdirRecursiveSync(
     basePath,
-    readdirResults: [],
-    pathsQueue: [basePath],
-  };
-
-  function read(path) {
-    const readdirResult = binding.readdir(
-      path,
-      context.encoding,
-      context.withFileTypes,
-    );
-
-    if (readdirResult === undefined) {
-      return;
-    }
-
-    processReaddirResult({
-      result: readdirResult,
-      currentPath: path,
-      context,
-    });
+    options.encoding,
+    withFileTypes,
+  );
+  if (result === undefined) {
+    return;
   }
-
-  for (let i = 0; i < context.pathsQueue.length; i++) {
-    read(context.pathsQueue[i]);
+  if (!withFileTypes) {
+    return result;
   }
-
-  return context.readdirResults;
+  // result = [names, types, parentPaths]
+  const { 0: names, 1: types, 2: parentPaths } = result;
+  const out = new Array(names.length);
+  for (let i = 0; i < names.length; i++) {
+    out[i] = new Dirent(names[i], types[i], parentPaths[i]);
+  }
+  return out;
 }
 
 /**

typings/internalBinding/fs.d.ts

@@ -180,6 +180,11 @@ declare namespace InternalFSBinding {
   function readdir(path: StringOrBuffer, encoding: unknown, withFileTypes: false, usePromises: typeof kUsePromises): Promise<string[]>;
 
   function readFileUtf8(path: StringOrBuffer, flags: number): string;
+  function readFileBuffer(path: StringOrBuffer, flags: number): Buffer;
+
+  function readdirRecursiveSync(path: StringOrBuffer, encoding: unknown, withFileTypes: true): [string[], number[], string[]];
+  function readdirRecursiveSync(path: StringOrBuffer, encoding: unknown, withFileTypes: false): string[];
+  function readdirRecursiveSync(path: StringOrBuffer, encoding: unknown, withFileTypes: boolean): string[] | [string[], number[], string[]];
 
   function readlink(path: StringOrBuffer, encoding: unknown, req: FSReqCallback<string | Buffer>): void;
   function readlink(path: StringOrBuffer, encoding: unknown, req: undefined, ctx: FSSyncContext): string | Buffer;
@@ -241,6 +246,9 @@ declare namespace InternalFSBinding {
 
   function writeFileUtf8(path: string, data: string, flag: number, mode: number): void;
   function writeFileUtf8(fd: number, data: string, flag: number, mode: number): void;
+
+  function writeFileBuffer(path: string, data: ArrayBufferView, flag: number, mode: number): void;
+  function writeFileBuffer(fd: number, data: ArrayBufferView, flag: number, mode: number): void;
 }
 
 export interface FsBinding {
@@ -283,6 +291,8 @@ export interface FsBinding {
   read: typeof InternalFSBinding.read;
   readBuffers: typeof InternalFSBinding.readBuffers;
   readdir: typeof InternalFSBinding.readdir;
+  readdirRecursiveSync: typeof InternalFSBinding.readdirRecursiveSync;
+  readFileBuffer: typeof InternalFSBinding.readFileBuffer;
   readFileUtf8: typeof InternalFSBinding.readFileUtf8;
   readlink: typeof InternalFSBinding.readlink;
   realpath: typeof InternalFSBinding.realpath;
@@ -295,6 +305,7 @@ export interface FsBinding {
   utimes: typeof InternalFSBinding.utimes;
   writeBuffer: typeof InternalFSBinding.writeBuffer;
   writeBuffers: typeof InternalFSBinding.writeBuffers;
+  writeFileBuffer: typeof InternalFSBinding.writeFileBuffer;
   writeFileUtf8: typeof InternalFSBinding.writeFileUtf8;
   writeString: typeof InternalFSBinding.writeString;