Viewing assumed changes by VQMOD

Question

Is there any application /software where you can see the outcome of the file that vqmod will change and see what it looks like?

example

$var = 'ABC';

In Vqmod make the changes to make ABC into 123,

<?xml version="1.0" encoding="UTF-8"?>
    <modification
                xmlns="https://github.com/vqmod/vqmod"
                xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                xsi:schemaLocation="https://github.com/vqmod/vqmod https://raw.githubusercontent.com/vqmod/vqmod/master/vqmod.xsd">
                >
        <id>Replace 123 with ABC</id>
        <version>1.0.0</version>
        <vqmver>2.5.0</vqmver>
        <author>qphoria</author>

        <file name="relative/path/myfile.php">
            <operation>
                <search position="replace"><![CDATA[
                $var = 'ABC';
                ]]></search>

                <add><![CDATA[
                $var = 123;
                ]]></add>
            </operation>
        </file> 
    </modification>

Above xml scriptis a slight modification from GitHub

but without applying/installing the xml file is there a way to see:

$var = 123; 

in a seperate window/output.

This is a simplistic example but for more complex vqmod's it would be helpful to see if one has messed any code mistakenly. I am not too familiar with the search process for the search field.

EDIT: What are VqCache files? Do they contain the changed files?

EDIT So I am starting to believe that the vqcache files are similar to what I've been looking for. It would be nice to see while I am typing up the vqmod though