Published by Rob Lambert,
Many modern browsers allow you to add add-ons, extensions, or plug-ins which give you increased functionality or allow you to perform actions and activities from within your browser.
There are literally thousands of these add-ons for all of the major browsers. I’ve discussed many of them in this series.
However it could be that these add-ons also interfere with the product under test causing you to spend time investigating a bug that might not be important to your target end user.
How to trouble shoot browser add-ons
This bug was un-reproducible on all other browsers except mine. After exploring all avenues of code we concluded that it might be a Firefox add-on. I had another virtual machine with the same version of Firefox and no add-ons and it worked ok, so the reasoning was sound.
I removed two add-ons at a time, as I typically run with about twenty+ add-ons to aid my testing. Two at a time seemed like a reasonable amount to remove to narrow down which add-on was the problem.
As it turned out it was the last two that I removed that resolved the issue.
Add-ons are immensely powerful but they can interfere with functionality.
Create a test machine (virtual or real) and install an absolutely clean (i.e. no add-ons or un-needed plug ins) browser and compare the two if you find it tricky to replicate issues. It could be a browser extension problem.
How to manage add-ons across multiple machines - http://lifehacker.com/272113/sync-your-firefox-extensions-and-profiles-across-computers
If you’re interested in a career in Software Testing then check out my book Remaining Relevant And Employable (Tester’s Edition) - it’s packed full of ideas about writing good CVs, communicating your value to employers and doing well in an interview.