Where did this come from? Don't think this applies for the WS client

Please see #414. WithoutbaseUrl, you cannot subscribe SpotUserDataStream on Testnet.

This isn't the correct way of doing this unfortunately. Take a look at how testnet is initiated with the other embedded REST clients. I would strongly prefer if you undo this and we look at doing this properly in a separate PR (although I appreciate you looking to fix this too). Will check the rest in the meantime.

As you asked, I pushed a new commit to undo this change.

Take a look at how testnet is initiated with the other embedded REST clients.

getSpotRestClient() function in line 756 of websocket-client.js file creates a new Rest Client. Here on the pinned issue, you described that to connect TestNet with Rest Client, we must provide baseURL.

Ah I see. Admittedly that's more for the REST client, but since then other contributors have added a simpler way to configure testnet on some of the REST clients. We'll get the spot testnet working properly for the websocket client in a separate PR - most likely similar to how it's working for futures:
https://github.com/tiagosiebler/binance/blob/master/src/websocket-client.ts#L958-L963

But that's for a separate PR to get this one finished & merged. Will review the rest of this.

Thanks, @tiagosiebler; I hope you'll provide a solution sooner because, currently, it is impossible to use WebSocket subscriptions on TestNet.

I'll keep a note high up in my list to get that prioritised

Any idea how we can make TypeScript automatically infer the order type from usage? For example, this is complaining because the first parameter of the generic type is missing:

However, it was never required before and would be a slight breaking change to require it now. It also seems redundant to force this:

      const order: NewSpotOrderParams<'MARKET'> = {
        symbol,
        side: 'BUY',
        type: 'MARKET',
        quantity: 0.1,
      };

When the value in the object already says exactly what the order type is. Any idea how to make TypeScript automatically infer TOrderType in a scenario like this? It's common to generate a request param (like an order object) before actually calling the function.

I pushed a new commit to make the generic optional.

If a generic is not provided, it will act as before because plain objects cannot infer generics from attribute values.

If a generic is provided, or a plain object is written directly in a function call, it would be inferred.

    const order: NewSpotOrderParams = {
      symbol,
      side: 'BUY',
      type: 'MARKET',
      quantity: 0.1,
    };

	// As before, cannot be inferred because of TypeScript limitation
    const result = await submitNewOrder(order); 

	// Inferred 
	const result2 = await submitNewOrder({
      symbol,
      side: 'BUY',
      type: 'MARKET',
      quantity: 0.1,
    }); 

	// Inferred with optional generic
    const orderX: NewSpotOrderParams<"MARKET"> = {
      symbol,
      side: 'BUY',
      type: 'MARKET',
      quantity: 0.1,
    };

    const resultX = await submitNewOrder(orderX); 

This is much better, thanks! This way there's no impact for anyone upgrading, just improvements/more flexibility.

Can you check if any other interfaces you've updated need to be updated as well? Or is this the only one?

There were four more, and I fixed them in the last commit.