Event subscription as the first request results in fromBlock parameter to be deleted

[jyeoniii]

Describe the bug
Race condition arises when the first request made by a Websocket provider is a subscription to an event which includes a request for historical logs.
It's been fixed in web3.js but it seems that the same bug still exists in caver-js.

• Bug Report Issue: WebsocketProvider with fromBlock doesnt return events from the past web3/web3.js#3389
• Bugfix PR: Fix historical event subscriptions when made as first provider request  web3/web3.js#3455

How to reproduce
Create Caver using WebsocketProvider and request event subscription for the first request.

const caver = new Caver('wss://api.baobab.klaytn.net:8652');
const contract = new caver.klay.Contract(abi, contractAddress);
contract.events.allEvents({ fromBlock: 0 }).on('data', console.log);

If I call something like await caver.klay.getAccounts() before the subscription, it works fine.

Expected behavior
All events of the contract from block 0 should be retrieved.

Environment (please complete the following information)

• caver-js version: 1.6.6
• OS and its version: macOS 11.3.1

[jimni1222]

@jyeoniii Thank you for reporting. You can use caver-js v1.6.7-rc.1 :)