CHANGELOG.md

@@ -1,3 +1,10 @@
+# [4.11.0](https://github.com/streamich/memfs/compare/v4.10.0...v4.11.0) (2024-07-27)
+
+
+### Features
+
+* volume implementation of .opendir() method ([7072fb7](https://github.com/streamich/memfs/commit/7072fb7545b6269c3f04f191a4853ad0f39ed15f))
+
 # [4.10.0](https://github.com/streamich/memfs/compare/v4.9.4...v4.10.0) (2024-07-27)
 
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "memfs",
-  "version": "4.10.0",
+  "version": "4.11.0",
   "description": "In-memory file-system with Node's fs API.",
   "keywords": [
     "fs",

src/Dir.ts

@@ -0,0 +1,151 @@
+import { Link } from './node';
+import { validateCallback } from './node/util';
+import * as opts from './node/types/options';
+import Dirent from './Dirent';
+import type { IDir, IDirent, TCallback } from './node/types/misc';
+
+/**
+ * A directory stream, like `fs.Dir`.
+ */
+export class Dir implements IDir {
+  private iteratorInfo: IterableIterator<[string, Link | undefined]>[] = [];
+
+  constructor(
+    protected readonly link: Link,
+    protected options: opts.IOpendirOptions,
+  ) {
+    this.path = link.getParentPath();
+    this.iteratorInfo.push(link.children[Symbol.iterator]());
+  }
+
+  private wrapAsync(method: (...args) => void, args: any[], callback: TCallback<any>) {
+    validateCallback(callback);
+    setImmediate(() => {
+      let result;
+      try {
+        result = method.apply(this, args);
+      } catch (err) {
+        callback(err);
+        return;
+      }
+      callback(null, result);
+    });
+  }
+
+  private isFunction(x: any): x is Function {
+    return typeof x === 'function';
+  }
+
+  private promisify<T>(obj: T, fn: keyof T): (...args: any[]) => Promise<any> {
+    return (...args) =>
+      new Promise<void>((resolve, reject) => {
+        if (this.isFunction(obj[fn])) {
+          obj[fn].bind(obj)(...args, (error: Error, result: any) => {
+            if (error) reject(error);
+            resolve(result);
+          });
+        } else {
+          reject('Not a function');
+        }
+      });
+  }
+
+  private closeBase(): void {}
+
+  private readBase(iteratorInfo: IterableIterator<[string, Link | undefined]>[]): IDirent | null {
+    let done: boolean | undefined;
+    let value: [string, Link | undefined];
+    let name: string;
+    let link: Link | undefined;
+    do {
+      do {
+        ({ done, value } = iteratorInfo[iteratorInfo.length - 1].next());
+        if (!done) {
+          [name, link] = value;
+        } else {
+          break;
+        }
+      } while (name === '.' || name === '..');
+      if (done) {
+        iteratorInfo.pop();
+        if (iteratorInfo.length === 0) {
+          break;
+        } else {
+          done = false;
+        }
+      } else {
+        if (this.options.recursive && link!.children.size) {
+          iteratorInfo.push(link!.children[Symbol.iterator]());
+        }
+        return Dirent.build(link!, this.options.encoding);
+      }
+    } while (!done);
+    return null;
+  }
+
+  // ------------------------------------------------------------- IDir
+
+  public readonly path: string;
+
+  closeBaseAsync(callback: (err?: Error) => void): void {
+    this.wrapAsync(this.closeBase, [], callback);
+  }
+
+  close(): Promise<void>;
+  close(callback?: (err?: Error) => void): void;
+  close(callback?: unknown): void | Promise<void> {
+    if (typeof callback === 'function') {
+      this.closeBaseAsync(callback as (err?: Error) => void);
+    } else {
+      return this.promisify(this, 'closeBaseAsync')();
+    }
+  }
+
+  closeSync(): void {
+    this.closeBase();
+  }
+
+  readBaseAsync(callback: (err: Error | null, dir?: IDirent | null) => void): void {
+    this.wrapAsync(this.readBase, [this.iteratorInfo], callback);
+  }
+
+  read(): Promise<IDirent | null>;
+  read(callback?: (err: Error | null, dir?: IDirent | null) => void): void;
+  read(callback?: unknown): void | Promise<IDirent | null> {
+    if (typeof callback === 'function') {
+      this.readBaseAsync(callback as (err: Error | null, dir?: IDirent | null) => void);
+    } else {
+      return this.promisify(this, 'readBaseAsync')();
+    }
+  }
+
+  readSync(): IDirent | null {
+    return this.readBase(this.iteratorInfo);
+  }
+
+  [Symbol.asyncIterator](): AsyncIterableIterator<IDirent> {
+    const iteratorInfo: IterableIterator<[string, Link | undefined]>[] = [];
+    const _this = this;
+    iteratorInfo.push(_this.link.children[Symbol.iterator]());
+    // auxiliary object so promisify() can be used
+    const o = {
+      readBaseAsync(callback: (err: Error | null, dir?: IDirent | null) => void): void {
+        _this.wrapAsync(_this.readBase, [iteratorInfo], callback);
+      },
+    };
+    return {
+      async next() {
+        const dirEnt = await _this.promisify(o, 'readBaseAsync')();
+
+        if (dirEnt !== null) {
+          return { done: false, value: dirEnt };
+        } else {
+          return { done: true, value: undefined };
+        }
+      },
+      [Symbol.asyncIterator](): AsyncIterableIterator<IDirent> {
+        throw new Error('Not implemented');
+      },
+    };
+  }
+}

src/__tests__/volume.test.ts

@@ -8,6 +8,7 @@ import { tryGetChild, tryGetChildNode } from './util';
 import { genRndStr6 } from '../node/util';
 import queueMicrotask from '../queueMicrotask';
 import { constants } from '../constants';
+import { IDirent } from '../node/types/misc';
 
 const { O_RDWR, O_SYMLINK } = constants;
 

src/node/options.ts

@@ -81,6 +81,14 @@ export const getReaddirOptsAndCb = optsAndCbGenerator<opts.IReaddirOptions, misc
   getReaddirOptions,
 );
 
+const opendirDefaults: opts.IOpendirOptions = {
+  encoding: 'utf8',
+  bufferSize: 32,
+  recursive: false,
+};
+export const getOpendirOptions = optsGenerator<opts.IOpendirOptions>(opendirDefaults);
+export const getOpendirOptsAndCb = optsAndCbGenerator<opts.IOpendirOptions, misc.IDir>(getOpendirOptions);
+
 const appendFileDefaults: opts.IAppendFileOptions = {
   encoding: 'utf8',
   mode: MODE.DEFAULT,

src/volume.ts

@@ -38,6 +38,8 @@ import {
   getRealpathOptions,
   getWriteFileOptions,
   writeFileDefaults,
+  getOpendirOptsAndCb,
+  getOpendirOptions,
 } from './node/options';
 import {
   validateCallback,
@@ -59,6 +61,7 @@ import {
 import type { PathLike, symlink } from 'fs';
 import type { FsPromisesApi, FsSynchronousApi } from './node/types';
 import { fsSynchronousApiList } from './node/lists/fsSynchronousApiList';
+import { Dir } from './Dir';
 
 const resolveCrossPlatform = pathModule.resolve;
 const {
@@ -2010,13 +2013,36 @@ export class Volume implements FsCallbackApi, FsSynchronousApi {
   public cpSync: FsSynchronousApi['cpSync'] = notImplemented;
   public lutimesSync: FsSynchronousApi['lutimesSync'] = notImplemented;
   public statfsSync: FsSynchronousApi['statfsSync'] = notImplemented;
-  public opendirSync: FsSynchronousApi['opendirSync'] = notImplemented;
 
   public cp: FsCallbackApi['cp'] = notImplemented;
   public lutimes: FsCallbackApi['lutimes'] = notImplemented;
   public statfs: FsCallbackApi['statfs'] = notImplemented;
   public openAsBlob: FsCallbackApi['openAsBlob'] = notImplemented;
-  public opendir: FsCallbackApi['opendir'] = notImplemented;
+
+  private opendirBase(filename: string, options: opts.IOpendirOptions): Dir {
+    const steps = filenameToSteps(filename);
+    const link: Link | null = this.getResolvedLink(steps);
+    if (!link) throw createError(ENOENT, 'opendir', filename);
+
+    const node = link.getNode();
+    if (!node.isDirectory()) throw createError(ENOTDIR, 'scandir', filename);
+
+    return new Dir(link, options);
+  }
+
+  opendirSync(path: PathLike, options?: opts.IOpendirOptions | string): Dir {
+    const opts = getOpendirOptions(options);
+    const filename = pathToFilename(path);
+    return this.opendirBase(filename, opts);
+  }
+
+  opendir(path: PathLike, callback: TCallback<Dir>);
+  opendir(path: PathLike, options: opts.IOpendirOptions | string, callback: TCallback<Dir>);
+  opendir(path: PathLike, a?, b?) {
+    const [options, callback] = getOpendirOptsAndCb(a, b);
+    const filename = pathToFilename(path);
+    this.wrapAsync(this.opendirBase, [filename, options], callback);
+  }
 }
 
 function emitStop(self) {