Error handling in promise-based logic -- when to process.exit and when not to

promise-error-handling

// In NodeJS I usually have this in it's own module, and use module.exports to expose it.
var errors = {
    failure : {
        action : function(error) {
            // Handle error and set some defaults
            console.warn('FAILURE: ' + error.message); // process.stdout.write(error.message);
        }
    },

    fatal : {
        action : function(error) {
            // Die!
            console.error('FATAL: ' + error.message); // process.stdout.write(error.message);
            // process.exit(1);
        }
    }
};


function asyncmethod(config) {
    var deferred = Promise.defer();

    setTimeout(function() {
        if (config.success) {
            deferred.resolve('We have data.');
        } else if (config.fail) {
            deferred.reject({
                type: 'failure',
                message: 'Something went wrong with the query.\nCatch this and move on',
                statusCode: 200
            });
        } else {
            deferred.reject({
                type: 'fatal',
                message : 'This is totally wrong! \nCrash the process.',
                statusCode: 500
            });
        }
    }, 2000);

    return deferred.promise;
}

// Call
asyncmethod({
    //change 'fatal' with 'fail' or 'success'
    fail: true
}).then(function(data) {
    console.info('SUCCESS: ' + data);
}).catch(function(error) {
    errors[error.type].action(error);
});