recover from error in q.js

recover_from_error.js

'use strict';

var Q = require('q');

function prepare(data) {
//    return Q(data);
    return Q.reject(new Error('special error1'));
}
function judgeError(err) {
    console.log('catch: ', err);

    if (~err.message.indexOf('special error').length) {
        //simulate calling other async function
        return Q('data recovered from error');
    }
    throw err;
}
function handleResult(data) {
    console.log('get data: ', data);
}

prepare('normal data').catch(judgeError).then(handleResult).catch(console.error);