zlatkov

process
    .on('unhandledRejection', (reason, promise) => {
         // Handle failed Promise
    })
    .on('uncaughtException', err => {
        // Handle failed Error   
        process.exit(1);
     });

zlatkov

window.addEventListener('error', e => { 
    // Get the error properties from the error event object 
    const { message, filename, lineno, colno, error } = e; 
});

zlatkov

var oldOnErrorHandler = window.onerror;
window.onerror = (msg, url, line, column, err) => {
    If (oldOnErrorHandler) {
        // Call any previously assigned handler.   
	oldOnErrorHandler.apply(this, arguments);
    }

    // The rest of your code
}

zlatkov

window.onerror = (msg, url, line, column, err) => {
     // ... handle error …
     return false;
};

zlatkov

function asyncFoo(x, callback) {
    // Some async code...
}

asyncFoo(‘testParam’, (err, result) => {
    If (err) {
        // Handle error.
    }
    // Do some other work.
});

zlatkov

function foo(x) {
    return new Promise((resolve, reject) => {
       if (typeof x !== 'number') {
            reject('x is not a number');
       }
        resolve(x);
    });
}

zlatkov

try {
    foo(‘test’)
    .then(x => console.log(x))
    .catch(err => console.log(err)); // The error is handled here.
} catch(err) {
    // This block is not reached since the thrown error is inside of a Promise.
}

zlatkov

function foo(x) {
    return new Promise((resolve, reject) => {
       if (typeof x !== 'number') {
            throw new TypeError('x is not a number');
       }
        resolve(x);
    });
}

zlatkov

try {
    foo(‘test’)
    .then(x => console.log(x))
    .catch(err => console.log(err));
} catch(err) {
    // Now the error is handed
}

zlatkov

foo(‘test’)
    .then(x => console.log(x))
    .catch(err => console.log(err));