bug: URLSearchParams(null) behavior deviates from WHATWG standard / browsers

[tbontb-iaq]

Version

v24.16.0

Platform

Linux nixos 7.0.9 #1-NixOS SMP PREEMPT_DYNAMIC Sun May 17 15:16:34 UTC 2026 x86_64 GNU/Linux

Subsystem

URLSearchParams

What steps will reproduce the bug?

(new URLSearchParams(null)).toString()

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

Every time

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

'null='

What do you see instead?

''

Additional information

When passing null to URLSearchParams constructor, Node.js deviates from the WHATWG URL and WebIDL specification, as well as the behavior in Chrome and Deno.

[KhafraDev]

Node.js deviates from the WHATWG URL and WebIDL specification

How does node deviate from either spec? Firefox behaves the same as node.

The logic makes sense to me. null is not a sequence<sequence> so it isn't converted, it isn't a record so it isn't converted, which means it falls back to the USVString converter "null" and is then parsed correctly.

[tbontb-iaq]

Firefox behaves the same as node.

What version of Firefox are you using? On my Firefox (Firefox for NixOS 150.0.3 (64-bit)), it behaves the same as Chrome and Deno.

[KhafraDev]

Oops, mistook the correct behavior for the bug...

[marcopiraccini]

Here a small PR for this: #63782