promise.catch

p.catch(onRejected

p.catch(function(reason) {
   // rejection
}

// overriding original Promise.prototype.then/catch just to add some logs
(function(Promise){
    var originalThen = Promise.prototype.then;
    var originalCatch = Promise.prototype.catch;
    
    Promise.prototype.then = function(){
        console.log('> > > > > > called .then on %o with arguments: %o', this, arguments
        return originalThen.apply(this, arguments
    };
    Promise.prototype.catch = function(){
        console.log('> > > > > > called .catch on %o with arguments: %o', this, arguments
        return originalCatch.apply(this, arguments
    };

})(this.Promise



// calling catch on an already resolved promise
Promise.resolve().catch(function XXX(){}

// logs:
// > > > > > > called .catch on Promise{} with arguments: Arguments{1} [0: function XXX()]
// > > > > > > called .then on Promise{} with arguments: Arguments{2} [0: undefined, 1: function XXX()]

var p1 = new Promise(function(resolve, reject) {
  resolve('Success'
}

p1.then(function(value) {
  console.log(value // "Success!"
  throw 'oh, no!';
}).catch(function(e) {
  console.log(e // "oh, no!"
}).then(function(){
  console.log('after a catch the chain is restored'
}, function () {
  console.log('Not fired due to the catch'
}

// The following behaves the same as above
p1.then(function(value) {
  console.log(value // "Success!"
  return Promise.reject('oh, no!'
}).catch(function(e) {
  console.log(e // "oh, no!"
}).then(function(){
  console.log('after a catch the chain is restored'
}, function () {
  console.log('Not fired due to the catch'
}

// Throwing an error will call the catch method most of the time
var p1 = new Promise(function(resolve, reject) {
  throw 'Uh-oh!';
}

p1.catch(function(e) {
  console.log(e // "Uh-oh!"
}

// Errors thrown inside asynchronous functions will act like uncaught errors
var p2 = new Promise(function(resolve, reject) {
  setTimeout(function() {
    throw 'Uncaught Exception!';
  }, 1000
}

p2.catch(function(e) {
  console.log(e // This is never called
}

// Errors thrown after resolve is called will be silenced
var p3 = new Promise(function(resolve, reject) {
  resolve(
  throw 'Silenced Exception!';
}

p3.catch(function(e) {
   console.log(e // This is never called
}

//Create a promise which would not call onReject
var p1 = Promise.resolve("calling next"

var p2 = p1.catch(function (reason) {
    //This is never called
    console.log("catch p1!"
    console.log(reason
}

p2.then(function (value) {
    console.log("next promise's onFulfilled" /* next promise's onFulfilled */
    console.log(value /* calling next */
}, function (reason) {
    console.log("next promise's onRejected"
    console.log(reason
}