firefoxPref can't change javascript.enabled

[krudnik]

Hello,

I have tried to measure a performance of a website without JS. I don't want just block js requests, but simulate that JS is disabled in the browser.
So I gave a try to https://sites.google.com/a/webpagetest.o...irefoxPref - the setting itself seems to be working fine (e.g. firefoxPref general.useragent.override "TEST" is ok).
But I do not see any difference between javascript.enabled (http://kb.mozillazine.org/Javascript.enabled) true or false:
http://www.webpagetest.org/result/151123...1/details/

Code:

firefoxPref    javascript.enabled    true
navigate    https://www.mozilla.org/en-US/firefox/new/

http://www.webpagetest.org/result/151123...1/details/

Code:

firefoxPref    javascript.enabled    false
navigate    https://www.mozilla.org/en-US/firefox/new/

Two questions:
1. Is there anything specific about javascript.enabled? Is this an expected behavior?
2. Any recommendation how to simulate javascript disabled?

[krudnik]

Ok, there is an easier - trivial way - to disable JS. Trying to solve my issue I found https://github.com/WPO-Foundation/webpag...browser.cc and this piece of code

Code:

if (_test._noscript) {
      user_prefs += "user_pref(\"javascript.enabled\", false);\r\n";
    }

led me to Advanced Settings > Advanced > Disable Javascript checkbox on http://www.webpagetest.org