Use globalThis.WebSocket in Node.js before of require('ws')

[jeroen]

We can use the Native WebSocket Client in Node.js on Node >= 21 instsead of hardcoding require('ws')

emscripten/src/lib/libsockfs.js

Lines 217 to 221 in 6ea9c28

	#if ENVIRONMENT_MAY_BE_NODE
	if (ENVIRONMENT_IS_NODE) {
	WebSocketConstructor = /** @type{(typeof WebSocket)} */(require('ws'));
	} else
	#endif // ENVIRONMENT_MAY_BE_NODE

An additional reason is that applications may use a proxy for globalThis.WebSocket to proxy webSocket communication through the main thread. However this gets ignored when emscripten hardcodes require('ws').

See

• Proxy WebSocket communication through the main thread r-wasm/webr#562
• Proxy WebSocket communication through the main thread r-wasm/webr#576
• Fix WebSocket proxy not working in Node.js jeroen/webr#1

[sbc100]

Great! I think we can/should just drop support for sockfs for node older than 21 to keep the code simple. I don't imagine there are many users of this API under node. Are you using this API in production under node?

[sbc100]

Would you have time to write a PR to simply remove this code?

[sbc100]

I noticed that the node version of this module does not support WebSocket Server so sadly we cannot completely remove our dependency on ws :(

[jeroen]

Right, we can remove it as a runtime dependency though. But for testing we still need the ws module to spin up a websocket server, but that is okay.