remove params from jsonrpc post payload if empty

[sreuland]

when the jsonrpc.post() method:

export async function post<T>(
  url: string,
  method: string,
  ...params: any
)

is webpacked for browser usage, there's some additional polyfill added to handle the spread params :

function post(url, method) {
    var _a;
    var params = [];
    for (var _i = 2; _i < arguments.length; _i++) {
        params[_i - 2] = arguments[_i];
    }

however, for methods such as getNetwork, getHealth, getLatestLedger that pass no params the result would still include params: [] in the json rpc post, which rpc server rejects with err:

{
    "jsonrpc": "2.0",
    "id": 1,
    "error": {
        "code": -32602,
        "message": "no parameters accepted"
    }
}

stellar/stellar-cli#458 will depend on this, it uses getLatestLedger

[tsachiherman]

I think that this PR is good on it's own. However, I'm not sure if the server behavior is correct. Could you please create a ticket to check the soroban-rpc handling in these cases ? ( i.e. we need to align to spec, whatever that would be )

[paulbellamy]

Yeah, seems like a bug in the server.

Edit: This bug in fact: stellar/soroban-rpc#40