contract.off still triggers events

[rick897887]

See code below, it listens on Sync events for the WBNB/BUSD pair on BNB chain, and should stop listening but it doesn't, the events keep getting logged to the console. Any idea why? I tried using the latest Ethers.js aswell but it threw an error on "JsonRpcProvider undefined", even though the code remained unchanged.

const { ethers } = require("ethers"); // ethers@5.7.2
const rpc = "INSERT_YOUR_RPC_URL_HERE";
const test = async (lp_address) =>
{
	provider = new ethers.providers.JsonRpcProvider(rpc);
	const contract = new ethers.Contract(lp_address, ["event Sync(uint112 reserve0, uint112 reserve1)"], provider);
	contract.on("Sync", async (r0, r1, event_) =>
	{
		console.log("Sync: r0="+r0+", r1="+r1);
	});
	contract.off("Sync");
}
test("0x58f876857a02d6762e0101bb5c46a8c1ed44dc16"); // WBNB/BUSD pair on BNB chain

[ricmoo]

Are you using the latest version?

[rick897887]

I'm using 5.7.2 as stated in the code I posted:
"const { ethers } = require("ethers"); // ethers@5.7.2"

Also I tried the latest version, as I said: "I tried using the latest Ethers.js aswell but it threw an error on "JsonRpcProvider undefined", even though the code remained unchanged."

[zemse]

I tried using the latest Ethers.js aswell but it threw an error on "JsonRpcProvider undefined", even though the code remained unchanged

In V6 ethers.providers.JsonRpcProvider changes to ethers.JsonRpcProvider. You can check migration docs.

[rick897887]

Thanks, but ideally I'd like to stick to V5, do you have any suggestions where I should start looking to try to fix the problem?

[zemse]

If you do this then does it stop?

const listener = async (r0, r1, event_) =>
	{
		console.log("Sync: r0="+r0+", r1="+r1);
	}

contract.on("Sync", listener);
contract.off("Sync", listener);

[rick897887]

That works, it stops listening on contract.off when using a non-anonymous function, thanks!