how can i intercept JS code before exectution in chrome

[wa-sunlab]

Hi,

I would like to create chrome extension to dev tool where i would like to intercept JS code of current web page before it is compiled or executed by browser , Actually i want to instrument JS code before it to run in browser.

Can anybody will help us , how it is possible ?

Many Thanks in advance.

[kdzwinel]

Hey, thanks for reaching out. Unfortunately, this is not the right place to ask this question. Try SO: http://stackoverflow.com/questions/tagged/google-chrome-extension or ChromiumDev slack: https://chromiumdev-slack.herokuapp.com/?linkId=18742368

[caspervonb]

@wa-sunlab Ping me with a stackoverflow question and I'll elaborate.

Thinamajig.js instruments with a few simple steps. TLDR;

1. Stop the document from loading with window.stop
2. Fetch the document with XHR.

3. Render scripts inert with a search and replace, e.g

   var html = request.responseText
    .replace(/type=\"text\/javascript\"/g, '')
    .replace(/<script/g, '<script type="live/javascript"');

4. Write the processed HTML with document.write.
5. Instrument and load the scripts.

[wa-sunlab]

@caspervonb http://stackoverflow.com/questions/40375167/how-can-i-intercept-js-code-before-exectution-in-chrome

[wa-sunlab]

@caspervonb Could you please explain me the step 3.

Many Thanks