Process Function Corrupts Images and fons files

[joeltonmats]

Hello, I have a task that works perfectly without use process function. But I have to analyze a specific file and replace a content, so it is require use process.
When I execute, the images and fonts corrupts, unfortunately. I just add for example

process: function (content, srcpath) {return content;},

It is enought for break the images and fonts. Any help ?