Why does a snap throw an error when using URLSearchParams?

[einaralex]

I'm trying to do a fetch inside of a snap and I need to format it with URLSearchParams.

await fetch('https://api.example.com/', {
      method: 'POST',
      body: new URLSearchParams({
        stuff: stuff
      }),
    });

and I recieved the error MetaMask - RPC Error: URLSearchParams is not a constructor

I tried importing URLSearchParams from 'url' and get the same result.
I know I can do this manually, but would be interested in knowing what would be causing this, is this a bug?

[einaralex]

It's documented here: https://docs.metamask.io/guide/snaps-development-guide.html#developing-a-snap

Snaps execute in a sandboxed environment that's running Secure EcmaScript (SES, see below). There is no DOM, no Node.js builtins, and no platform-specific APIs other than MetaMask's wallet global object

[Montoya]

Sorry we didn't see this in time to give you an answer! Most of our team was at EthCC or on holiday :)