PUBLIC MARKS from decembre with tags test & extention

One method of finding the conflicting add-on is to disable each of your extensions one by one until you find the culprit. If you have more than just a handful of extensions, this can be very time consuming. A more efficient method would be to disable only half of the extensions then test to see if the conflict is resolved. If it is, then you know the culprit is one of the disabled extensions. If not, you need to re-enable those extensions and disable the other half. You go back and forth disabling/enabling extensions until you whittle down the list to a single culprit. While the most efficient method, it can be very confusing keeping track of which extensions to disable/enable. This is what FECT does. A FECT session consists of several iterations of different extension configurations. It will randomly disable/enable one half of the installed extensions during each iteration depending on how you answer the question "Was the conflict resolved?". During my test runs, FECT was able to determine the culprit extension after about five to seven iterations (with 42 installed extensions).

Before we bring new features to Firefox, we give them a test run to make sure they’re right for our users. To help determine which features we add and how exactly they should work, we created the Test Pilot program.