Warning: DOMDocument::loadXML(): Empty string supplied as input in vendor/pdt256/shipping/src/USPS/Rate.php on line 166

[dranzd]

When the shipping provider's api fails to return a response or returns an empty string, the DOMDocument is throwing a warning and I am unable to catch this in my application.

This becomes a problem when working with XmlHttpRequest as I need to return a JSON format but it becomes invalid as I can't handle the warning thrown by DOMDocument.

Is it possible to fix this so that this code below

https://github.com/pdt256/shipping/blob/190b1d74c9573e66c5359350a70054d84d7436c9/src/USPS/Rate.php#L162-L167

would suppress the $dom->loadXml like

    protected function process()
    {
        try {
            $dom = new DOMDocument('1.0', 'UTF-8');
            @$dom->loadXml($this->response);

or load $this->response only if it's not empty like

    protected function process()
    {
        try {
            $dom = new DOMDocument('1.0', 'UTF-8');

            if (empty($this->response)) {
                $dom->loadXml('<root></root>');
            } else {
                $dom->loadXml($this->response);
            }

Please let me know if you need more information regarding this issue. I can also do a PR if needed.

Thanks.