Javascript error messages, custom object representation

Question

Is there a way in javascript to make the runtime use a different object representation in the error messages.

A typical error message

Uncaught TypeError: Object [object Object] has no method 'toggle'

It would be helpful if we can give a better representation to the object than [object Object] .In other languages you can make it print a better representation of the object by overriding toString().

However it looks like overriding toString has no effect in this case.

Answer 1

I would use a try...catch and throw your own error messages:

var obj = {
  name: 'obj',
  fn: function () {
    return 'hallo';
  }
}


function hasMethod(obj, fn) {
    try {
        if (!obj[fn]) {
            var err = obj.name + ' does not have a method ' + fn;
            throw new Error(err)
        }
    } catch (e) {
        console.log(e)
    }
}

hasMethod(obj, 'moose'); // obj does not have a method moose

Fiddle