CoinTools v0.0.4: Conversion Between Two Fiat or Fiat-Coin + 24 Hour Total Market Cap Chart

// ajax calling API to return the price of USD for coin
const getPriceOfUSD = (coin) => {
    return new Promise((resolve, reject) => {
        let api = "https://api.coinmarketcap.com/v1/ticker/" + coin + '/';
        fetch(api, {mode: 'cors'}).then(validateResponse).then(readResponseAsJSON).then(function(result) {
            resolve(result[0].price_usd);
        }).catch(function(error) {
            logit('Request failed: ' + api + ": " + error);
            reject(error);
        });
    });
}
 
// ajax calling API to return the price of currency for 1 BTC
const getPriceOf1BTC = (currency) => {
    return new Promise((resolve, reject) => {
        let api = "https://api.coinmarketcap.com/v1/ticker/bitcoin/?convert=" + currency.toUpperCase();
        fetch(api, {mode: 'cors'}).then(validateResponse).then(readResponseAsJSON).then(function(result) {            
            resolve(result[0]['price_' + currency.toLowerCase()]);
        }).catch(function(error) {
            logit('Request failed: ' + api + ": " + error);
            reject(error);
        });
    });
}
 
// ajax calling API to return the price of USD for coin
const getPriceOf = (coin, fiat) => {
    return new Promise((resolve, reject) => {
        let api = "https://api.coinmarketcap.com/v1/ticker/" + coin + '/?convert=' + fiat.toUpperCase();
        fetch(api, {mode: 'cors'}).then(validateResponse).then(readResponseAsJSON).then(function(result) {
            resolve(result[0]['price_' + fiat.toLowerCase()]);
        }).catch(function(error) {
            logit('Request failed: ' + api + ": " + error);
            reject(error);
        });
    });
}
 
// ajax get conversion
const getConversion = async(coin1, coin2) => {
    // determine if input is coin or currency
    let is_coin1 = !currency_array.includes(coin1.toUpperCase());
    let is_coin2 = !currency_array.includes(coin2.toUpperCase());
    // both are coins
    if ((is_coin1) && (is_coin2)) {
        let api1 = getPriceOfUSD(coin1);
        let api2 = getPriceOfUSD(coin2);
        return await api1 / await api2;
    }
    // both are currencies e.g. USD to CNY
    if ((!is_coin1) && (!is_coin2)) {
        let api1 = getPriceOf1BTC(coin1);
        let api2 = getPriceOf1BTC(coin2);
        return await api2 / await api1;
    }
    // converting coin1 to fiat coin2
    if (is_coin1) {
        return await getPriceOf(coin1, coin2);
    } else { // convert coin2 to fiat coin1
        return 1.0/await getPriceOf(coin2, coin1);
    }
}