Every time I want to add new code to my site I have to modify the file outside of users view to debug it before updating the real file users see.
I usually create a copy of the file I want to change and test all changes on it but sometimes this files only appear included on another and I have to create two copies and sometimes it becomes even more complicated.
How is this normally done? Are there any tools to simplify the process, for example and enviroment to test my site on my PC so I don't have to upload files to the server each time I update something. Any info about beta testing new features will be thanked.
Most people have a 2nd server (potentially a virtual machine) configured exactly the same as their live (production) website. Where this 2nd server is located is completely up to you, but it should match your live site by using the same versions of software and same file structure.