Bug in fs promise APIs

[theanarkh]

Version

main

Platform

MacOS

Subsystem

fs

What steps will reproduce the bug?

// node --permission demo.mjs
import fs from "fs"

await fs.promises.mkdtemp('asdf')

How often does it reproduce? Is there a required condition?

always

What is the expected behavior? Why is that the expected behavior?

throw an error: Error: Access to this API has been restricted. Use --allow-fs-write to manage permissions.

What do you see instead?

throw and error: TypeError: Method Promise.prototype.then called on incompatible receiver undefined.

Additional information

This is because C++ layer does not return the promise to JS layer(just reject the promise in C++ layer) when an error occurs(Libuv error or permission error).

Refs: #58747 and #58996

[allandiegoasilva]

@theanarkh Is this issue already resolved on Windows and Linux, and only pending on macOS?

[theanarkh]

No, It is platform-independent.

[allandiegoasilva]

@theanarkh

I tested this on Node.js v22.15.0 running on macOS, and the issue no longer occurs.

When executing:

import fs from "fs";
await fs.promises.mkdtemp('asdf');

With the command:

node --permission=read-only demo.mjs

I receive the expected error:

Error: Access to this API has been restricted
....
code: 'ERR_ACCESS_DENIED',
permission: 'FileSystemRead'

This means the runtime now correctly throws a structured error instead of returning undefined, which previously caused a TypeError.

So, from my testing, this issue appears to be resolved, at least on macOS with Node v22.15.0.

[theanarkh]

The error of your test is throw by fs.promise.open when load the demo. mjs file. So it can not trigger the TypeError: Method Promise.prototype.then called on incompatible receiver undefined error because it does not call fs.promises.mkdtemp. You can use v24 or main branch to test it.

[HumaneLogic]

@theanarkh

tested on linux mint , on Node.js v24.1.0
with node --permission=read-only index.js
i get
Error: Access to this API has been restricted
....
code: 'ERR_ACCESS_DENIED',
permission: 'FileSystemRead'

[theanarkh]

You will get Error: Access to this API has been restricted when Node.js version < 24.2.0, and get TypeError: Method Promise.prototype.then called on incompatible receiver undefined when version >= 24.2.0. Because Node.js add allow-fs-read for app entrypoint by default (See this PR).

[bakkot]

@theanarkh This seems like a duplicate of #58747; was it fixed by #58996?

[theanarkh]

Yes. Because this bug affects most of the fs Promise API, so I created a separate issue.