CryptoKey string tag imprecise for detection

[brettz9]

Version

v18.12.1

Platform

Darwin MacBook-Air-2.local 22.2.0 Darwin Kernel Version 22.2.0: Fri Nov 11 02:04:44 PST 2022; root:xnu-8792.61.2~4/RELEASE_ARM64_T8103 arm64

Subsystem

No response

What steps will reproduce the bug?

import {webcrypto as crypto} from 'node:crypto';
const key = await crypto.subtle.generateKey(
  {
    name: 'HMAC',
    hash: {name: 'SHA-512'}
  },
  true, // Extractable
  ['sign', 'verify']
);
const stringTag = Object.prototype.toString.call(key).slice(8, -1);
console.log(stringTag);

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

Always

What is the expected behavior?

On the browser, this logs CryptoKey and allows for detection of object type and we expect it here.

What do you see instead?

Object

Additional information

This can be readily remedied by adding Symbol.toStringTag to the CryptoKey class returning the value, "CryptoKey".

[bnoordhuis]

Pull request welcome, but...

We do WPT conformance testing so this is probably not a spec requirement. It'd be best to update upstream WPT first before making changes to node. There's a CryptoKey validator you could add a check to.

[brettz9]

Thanks for the info. IIRC, there are some separate WebIDL-based tests in WPT which might cover class string (string tag) checks for interfaces (and these tests weren't always contained in the same part of the directory structure).

As far as a spec basis for this, there is some mention of class strings in https://webidl.spec.whatwg.org/ , though I only see it mentioned there for interface prototypes, not necessarily interface objects. I wonder if it is implied elsewhere within WebIDL though.

[panva]

I am not sure about this being a spec requirement too but if all existing implementations adhere, I don't see the point of not adding this to Node.js and WPT.

PR for the WPT repository web-platform-tests/wpt#37716.