There is a website I'm working with that uses a JavaScript file to set a foo header. This foo header is a result of some sort of calculation. My goal is to figure out how foo is calculated. However, the JavaScript file is also heavily obfuscated and it is quite large. So, I cannot simply go to the file and type CTRL+F to look for the header name.

I have found that it is possible to find where cookies are set via

debug(Object.getOwnPropertyDescriptor(Document.prototype, 'cookie').set)

Is there a way for me to do something similar except for a header?