Window.onerror and [object Event]

Question

I have an error code on my website that saves Javascript errors to a file, so later I can see if there are problems with my code in some browsers.

Sometimes I get an error message, for example the message: [object Event] url: undefined string: undefined , so I don’t know where the error is.

How to get additional information from the message when it is [object Event], so I can find out from which file and line number the error is sent.

window.onerror = error;

function error(message, url, line) {

   // sometimes message is [object Event]

}

I think something like this.

window.onerror = error;

function error(message, url, line) {

   // sometimes message is [object Event]


    if (typeof message === 'object') {

        message = message
            + ' + '
            + message.url
            + ' + '
            + message.lineno;

    }

}

Trying, but I get Uncaught TypeError: Object # does not have a 'serialize' method

if (typeof message === 'object') {

   message = JSON.serialize(message);

}

With JSON.stringify (message) I get Uncaught TypeError: convert circular structure to JSON

if (typeof message === 'object') {

   message = JSON.stringify(message);

}

Answer 1

, - [someting Something] JS, , . console.log(message) .

{
  somethingHere : 'data',
  anotherHere : 'more data'
}

, :

theObject.somethingHere //data

, something - .

message.something

Answer 2

[Event object]? :

var messageString = '';
for (var x in message) {
  if (messageString) messageString += ', ';
  messageString += x + ': ' + message[x];
}
message = '{' + messageString + '}';

- , , , .