Reverse engineer a .deb file?

Our Grafana developer left a while back. Recently I found a typo in the app.js file under the public/build directory. From what I can find in our repo the source code for this particular portion is not there. Is it possible for me to reverse back to the original source just by extracting the .deb file and the various .tar files under it? Are the files found in the public/build directory created when I compile using grunt? I know I am asking questions a Grafana developer would know easily. I have been watching tutorials and reading the docs but this particular question about reverse engineering with a .deb I have not been able to find (since most people wouldn’t need to do this) … any help would be appreciated.