index.js

// este codigo ya está guardado como promesasAsyncAwait.js

//veremos como crear una promesa
new Promise((resolve, reject) => {
    resolve(5)
    reject(new Error())
});

const toNumber = n => Number(n);
//const multiply = n => n * 2;
const multiply = n => {
    console.log("Multiply", n);
    if(n > 10) throw new Error("Error");
    return n * 2;
}
const print = n => console.log(n);
const catchAndPrint = (err) => {
    console.log(err);
    return 1;
}

const request = (url) => {
    return new Promise((resolve, reject) => {
        const req = new XMLHttpRequest();
        req.open("GET", url);

        req.onload = () => {
            if (req.status === 200){
                resolve(req.responseText);
            }
            else{
                reject(new Error('Error al cargar'));
            }
        }
        req.onerror = () => {
            reject(new Error("Error de red"));
        }
        req.send();
    })
};

const prom = async () => {}

const call = async (url) => {
    let response, response2;
    try {
        response = await request(url);
    }catch (error) {
        catchAndPrint(error);
        response = 7;
    }

    try{
        response2 = await request(url);
    }catch (error) {
        catchAndPrint(error);
        response2 = 8;
    }

    const n1 = toNumber(response);
    const n2 = toNumber(response2);
    print(n1 * n2);
}
call("./numero2.txt");