Append info to existing error?

Question

Append info to existing error?

If I have a async function with a callback inside like this:

fs.readFile(req.files.file.path, function (err, data) {
    return callback(err, data);
});

And I'd like to append or add a simple message to the existing error object (err) (hopefully it's an object, may be string). Whats the best way to do so? I can wrap this error inside another?

javascript
node.js
asynchronous
error-handling

Answer 1

Try this:

fs.readFile(req.files.file.path, function (err, data) {
    err.myProperty = 'test';
    return callback(err, data);
});

Of course you can create another object and make a property "error" with the original err object.