Currency converter task for Uber coding interview

currency-converter.js

const exchangeRates = [
    {
        "from": "TRY",
        "to": "USD",
        "rate": 0.6,
    },
    {
        "from": "EUR",
        "to": "TRY",
        "rate": 5.5,
    },
    {
        "from": "BGN",
        "to": "EUR",
        "rate": 0.51,
    },
];

function getExchangeRate(fromInitial, toInitial) {
    const results = [];
    const backtrack = function(currency, rates) {
        // console.log(currency, rates, start);

        if (currency === toInitial) {
            results.push([...rates]);
            return;
        }

        for (let i = 0; i < exchangeRates.length; i++) {
            if (exchangeRates[i].from === currency) {
                rates.push(exchangeRates[i]);
                backtrack(exchangeRates[i].to, rates, i + 1);
                rates.pop();
            }
        }
    };

    backtrack(fromInitial, []);

    console.log(results);

    if (results.length === 0) {
        throw new Error('Cannot determine rate!');
    }

    // multiply rates
    return results[0].reduce((result, { rate }) => {
        return result * rate;
    }, 1);
}

console.log(getExchangeRate('BGN', 'TRY')); // 2.82