denoland/deno · error · NodeTypeError

ERR_MISSING_ARGS

ERR_MISSING_ARGS

Error message

The "path" argument must be specified

What it means

The internal Dir class behind fs.opendir()/fs.opendirSync() throws ERR_MISSING_ARGS when constructed with a falsy path. The public fs.opendir entry points validate the path themselves, so reaching this usually means an empty string or undefined slipped past upstream validation, or the internal class was used directly.

Source

Thrown at ext/node/polyfills/_fs/_fs_dir.ts:38

  SymbolAsyncIterator,
  SymbolAsyncDispose,
  SymbolDispose,
  ArrayIteratorPrototypeNext,
  SymbolIterator,
} = primordials;

// Note: unlike `fs.readdir`, `fs.opendir`/`Dir` streams entries in filesystem
// order and does NOT sort them, matching Node.js (libuv's `uv_fs_readdir`, as
// opposed to `uv_fs_scandir` which backs `readdir`). Do not add sorting here.
export default class Dir {
  #dirPath: string | Uint8Array;
  #syncIterator!: Iterator<Deno.DirEntry, undefined> | null;
  #asyncIterator!: AsyncIterator<Deno.DirEntry, undefined> | null;
  #closed = false;

  constructor(path: string | Uint8Array) {
    if (!path) {
      throw new ERR_MISSING_ARGS("path");
    }
    this.#dirPath = path;
  }

  get path(): string {
    if (ObjectPrototypeIsPrototypeOf(Uint8ArrayPrototype, this.#dirPath)) {
      return new TextDecoder().decode(this.#dirPath);
    }
    return this.#dirPath;
  }

  // deno-lint-ignore no-explicit-any
  read(callback?: (...args: any[]) => void): Promise<Dirent | null> {
    return new Promise((resolve, reject) => {
      if (this.#closed) {
        const err = new ERR_DIR_CLOSED();
        if (callback) {
          callback(err);

View on GitHub (pinned to 89f33cbef2)

Solutions

1. Pass a concrete non-empty path (string, Buffer, or URL)
2. Validate before the call: if (!path) throw new Error('path required')
3. Log the offending value at the call site to find which stage of your pipeline lost it

Example fix

// before
fs.opendir(dirName, (err, d) => { ... }); // dirName is undefined/''

// after
if (typeof dirName !== "string" || dirName === "") {
  throw new Error("opendir requires a non-empty path");
}
fs.opendir(dirName, (err, d) => { ... });

function toNonEmptyPath(p: string | Buffer | URL | undefined): string | Buffer | URL {
  if (p === undefined || p === null || p === "") {
    throw new Error("A non-empty path is required for directory operations");
  }
  return p;
}

const dir = fs.opendirSync(toNonEmptyPath(config.dir));

function isValidDirPath(p: unknown): p is string | Buffer | URL {
  if (typeof p === "string") return p.length > 0;
  return p instanceof Buffer || p instanceof URL;
}

When it happens

Trigger: fs.opendir(undefined) or fs.opendir('') on a code path where earlier validation is bypassed; constructing the internal Dir class directly from polyfill internals.

Common situations: Path assembled from optional config that is undefined when unset; destructuring that misses/renames the path variable; empty string left after trimming user input.

Related errors

• A file exists at the destination: ${destStr}
• ERR_DIR_CLOSED
• No callback function supplied
• ERR_INVALID_ARG_TYPE
• invalid ${name}, must not be infinity or NaN

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/bd75b0abfe43dea1. Report an issue: GitHub.