Validate Paginated Data

import ccxt from '../../js/ccxt.js';
import ololog from 'ololog'
import ansicolor from 'ansicolor';

const log = ololog.configure ({ locate: false })

ansicolor.nice

//-----------------------------------------------------------------------------

/*
* Warning: Sometimes the exchanges have gaps in their OHLCV data, so it does not mean
* that CCXT is broken if you see gaps in the chart.
*/

async function fetchData(exchange, symbol, timeframe) {
   await exchange.loadMarkets()
   // exchange.verbose = true;
   const duration = exchange.parseTimeframe (timeframe) *1000; // in milliseconds
   const ohlcv = await exchange.fetchOHLCV (symbol, timeframe, undefined, undefined, {'paginate': true, 'paginationCalls': 5})
   validateTimeframes(ohlcv, duration, exchange, symbol)
}

function validateTimeframes(ohlcv, duration, exchange, symbol) {
   for (let j = 0; j < ohlcv.length; j++) {
       const [timestamp, open, high, low, close, volume] = ohlcv[j]
       if (j > 0) {
           const [prevTimestamp, prevOpen, prevHigh, prevLow, prevClose, prevVolume] = ohlcv[j - 1]
           if (timestamp - prevTimestamp !== duration) {
               log.red ('[' + j + ']',exchange.id, symbol, 'OHLCV data is not continuous, at', exchange.iso8601 (timestamp), 'diff:', ((timestamp - prevTimestamp) / 1000), 's expected:', duration/ 1000, 's')
           }
       }
   }
   log.green(exchange.id, symbol, `All the ${ohlcv.length} candles returned are continuous`)
}

async function main () {

   const exchanges = {
       'binance': 'BTC/USDT',
       'bitget': 'BTC/USDT',
       'kucoin': 'BTC/USDT',
       'kucoinfutures': 'BTC/USDT:USDT',
       'okex': 'BTC/USDT',
       'bybit': 'BTC/USDT'
   }
   const timeframe = '1m';
   const keys = Object.keys (exchanges)
   const promises = [];
   for (let i = 0; i < keys.length; i++) {
       const name = keys[i]
       const symbol = exchanges[name]
       const exchange = new ccxt[name] ({ enableRateLimit: true })
       promises.push(fetchData(exchange, symbol, timeframe))
   }
   await Promise.all(promises)
}

main()