Watch Fetch Many Exchanges Many Ordersbooks

'use strict';
import ccxt from '../../js/ccxt.js';
console.log('CCXT Version:', ccxt.version); // eslint-disable-line import/no-named-as-default-member
async function watchOrderBook(exchange, symbol) {
   while (true) { // eslint-disable-line no-constant-condition
       try {
           const method = exchange.has.watchOrderBook ? 'watchOrderBook' : 'fetchOrderBook';
           const orderbook = await exchange[method](symbol);
           console.log(new Date(), exchange.id, symbol, orderbook['asks'][0], orderbook['bids'][0]);
       }
       catch (e) {
           console.log(symbol, e);
           process.exit();
       }
   }
}
async function watchExchange(exchangeId, symbols) {
   const exchange = new ccxt.pro[exchangeId](); // eslint-disable-line import/no-named-as-default-member
   await exchange.loadMarkets();
   await Promise.all(symbols.map((symbol) => watchOrderBook(exchange, symbol)));
}
async function main() {
   const streams = {
       'ftx': [
           'BTC/USDT',
           'ETH/BTC',
       ],
       'coinex': [
           'BTC/USDT',
           'ETH/BTC',
       ],
   };
   const entries = Object.entries(streams);
   await Promise.all(entries.map(([exchangeId, symbols]) => watchExchange(exchangeId, symbols)));
}
main();