Getting `Unexpected end of JSON input`

const ethers = require('ethers');

const addresses = {
WBNB: '0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c',
BUSD: '0xe9e7cea3dedca5984780bafc599bd69add087d56',
factory: '0xcA143Ce32Fe78f1f7019d7d551a6402fC5350c73',
router: '0x10ed43c718714eb63d5aa57b78b54704e256024e',
recipient: ''
}

const privateKey = '';

const mygasPrice = ethers.utils.parseUnits('5', 'gwei');

const provider = new ethers.providers.WebSocketProvider('wss://apis-sj.ankr.com/.............');
const wallet = new ethers.Wallet(privateKey);
const account = wallet.connect(provider);

const factory = new ethers.Contract(
addresses.factory,
['event PairCreated(address indexed token0, address indexed token1, address pair, uint)'],
account
);
const router = new ethers.Contract(
addresses.router,
[
'function getAmountsOut(uint amountIn, address[] memory path) public view returns (uint[] memory amounts)',
'function swapExactTokensForTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts)'
],
account
);

const wbnb = new ethers.Contract(
addresses.WBNB,
[
'function approve(address spender, uint amount) public returns(bool)',
],
account
);

console.log('Before Approve');
const valueToapprove = ethers.utils.parseUnits('0.01', 18);
const init = async () => {
const tx = await wbnb.approve(
router.address,
valueToapprove,
{
gasPrice: mygasPrice,
gasLimit: '162445'
}
);
console.log('After Approve');
const receipt = await tx.wait();
console.log('Transaction receipt');
console.log(receipt);
}

factory.on('PairCreated', async (token0, token1, pairAddress) => {
console.log('after factory.on:');
console.log(' New pair detected ================= token0: ${token0} token1: ${token1} pairAddress: ${pairAddress} ');

//The quote currency needs to be WBNB (we will pay with WBNB)
let tokenIn, tokenOut;
if(token0 === addresses.WBNB) {
tokenIn = token0;
tokenOut = token1;
}

if(token1 == addresses.WBNB) {
tokenIn = token1;
tokenOut = token0;
}

//The quote currency is not WBNB
if(typeof tokenIn === 'undefined') {
return;
}

//We buy for 0.1 BNB of the new token
//ethers was originally created for Ethereum, both also work for BSC
//'ether' === 'bnb' on BSC
console.log('line 87');
const amountIn = ethers.utils.parseUnits('0.01', 'ether');
const amounts = await router.getAmountsOut(amountIn, [tokenIn, tokenOut]);
//Our execution price will be a bit different, we need some flexbility
const amountOutMin = amounts[1].sub(amounts[1].div(10));

console.log('line 92');
console.log(' Buying new token ================= tokenIn: ${amountIn} ${tokenIn} (WBNB) tokenOut: ${amountOutMin} ${tokenOut} ');
console.log('line 101');

const tx = await router.swapExactTokensForTokens(
amountIn,
amountOutMin,
[tokenIn, tokenOut],
addresses.recipient,
Math.floor(Date.now() / 1000) + 60 * 20, // 20 minutes from the current Unix time
{
gasPrice: mygasPrice,
gasLimit: 162445
}
);
console.log('line 117');
const receipt = await tx.wait();
console.log('Transaction receipt');
console.log('receipt');
});

init();

I’m getting this error:

Before Approve
After Approve
undefined:1


SyntaxError: Unexpected end of JSON input
    at JSON.parse (<anonymous>)
    at WebSocketProvider._this._websocket.onmessage (C:\Users\Kadiem Alqazzaz\Desktop\psbot\node_modules\@ethersproject\providers\lib\websocket-provider.js:106:31)
    at WebSocket.onMessage (C:\Users\Kadiem Alqazzaz\Desktop\psbot\node_modules\ws\lib\event-target.js:132:16)
    at WebSocket.emit (events.js:375:28)
    at Receiver.receiverOnMessage (C:\Users\Kadiem Alqazzaz\Desktop\psbot\node_modules\ws\lib\websocket.js:834:20)
    at Receiver.emit (events.js:375:28)
    at Receiver.dataMessage (C:\Users\Kadiem Alqazzaz\Desktop\psbot\node_modules\ws\lib\receiver.js:437:14)
    at Receiver.getData (C:\Users\Kadiem Alqazzaz\Desktop\psbot\node_modules\ws\lib\receiver.js:367:17)
    at Receiver.startLoop (C:\Users\Kadiem Alqazzaz\Desktop\psbot\node_modules\ws\lib\receiver.js:143:22)
    at Receiver._write (C:\Users\Kadiem Alqazzaz\Desktop\psbot\node_modules\ws\lib\receiver.js:78:10)

[erencnt]

same issue with ankr web socket

[Legend28469]

For anyone looking for a temporary fix, it looks like it’s an Ankr problem from my testing. I haven’t had that problem at all using Moralis