`attributeNameFn` callback receives an undefined attributeValue

[ediblecode]

Repro steps:

Provide an attributeNameFn, where the second argument is an attributeValue as per the docs. For example:

xml2js(`<root><element attr="val">content</element></root>`, {
    attributeNameFn: (attributeName, attributeValue, parentElement) => {
        console.log({ attributeValue });

        return attributeName;
    },
});

Expected result

The received attributeValue argument is the value of the current attribute.

In the above example the expected result is logging { attributeValue: 'val' }.

Actual result

The received attributeValue argument in the attributeNameFn is undefined.

Further details

Looks like it's being caused by:

https://github.com/nashwaan/xml-js/blob/f0376f265c4f299100fb4766828ebf066a0edeec/lib/xml2js.js#L150-L154

Notice the value is being deleted before being passed into the function as the second argument. So passing temp here looks like it'd solve the issue.