Binance Fetch Ohlcv Many Symbols Promise Then Callbacks

// @NO_AUTO_TRANSPILE
'use strict';
import ccxt from '../../js/ccxt.js';
console.log('CCXT Version:', ccxt.version);
function symbolLoop(exchange, symbol, timeframe) {
    exchange.fetchOHLCV(symbol, timeframe).then(ohlcvs => {
        console.log(exchange.iso8601(exchange.milliseconds()), exchange.id, symbol, ohlcvs.length, 'OHLCV candles received');
        setTimeout(() => symbolLoop(exchange, symbol, timeframe), 0);
    }).catch(e => {
        console.log(exchange.iso8601(exchange.milliseconds()), exchange.id, symbol, e.constructor.name, e.message);
        setTimeout(() => symbolLoop(exchange, symbol, timeframe), 0);
    });
}
function main() {
    const exchange = new ccxt.binance();
    // exchange.verbose = true // uncomment for debugging purposes if necessary
    const symbols = [
        'BTC/USDT', // unified symbols used here as opposed to exchange-specific market ids
        'ETH/USDT', // more about unified symbols vs exchange-specific ids here:
        'ADA/USDT', // /docs/manual#markets
    ];
    const timeframe = '1m';
    exchange.loadMarkets().then(markets => {
        for (const symbol of symbols) {
            setTimeout(() => symbolLoop(exchange, symbol, timeframe), 0);
        }
    });
}
main();