Javascript - Override console.log and keep the old function

Question

I would like to override console.log and call it on my new function.

I try something like this but I get Uncaught TypeError: Illegal invocation:

console.log = function() {
  this.apply(window, arguments);
}.bind(console.log);

console.log('as');

This is my goal:

console.error(exception); should do:

console.error = function() {
  if (typeof exception.stack !== 'undefined') {
    console.error(exception.stack);
  } else {
    console.error.apply(windows, arguments);
  }
}.bind(console.error);

console.error('as');
console.error({stack: 'my stack....'});

EDIT: Actually, it works in firefox and not in Chrome... It's a bug in Chrome: https://code.google.com/p/chromium/issues/detail?id=167911

Answer 1

You can have something like that:

console.error = (function() {
    var error = console.error;

    return function(exception) {
        if (typeof exception.stack !== 'undefined') {
            error.call(console, exception.stack);
        } else {
            error.apply(console, arguments);
        }
    }
})();

Answer 2

The best way to achieve what you want :

// define a new console
var console=(function(oldCons){
    return {
        log: function(text){
            oldCons.log(text);
            // Your code
        },
        info: function (text) {
            oldCons.info(text);
            // Your code
        },
        warn: function (text) {
            oldCons.warn(text);
            // Your code
        },
        error: function (text) {
            oldCons.error(text);
            // Your code
        }
    };
}(window.console));

//Then redefine the old console
window.console = console;