Too many browser extensions

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
I had a problem where one of my add-ons was stopping some JavaScript functionality from firing even though there were no settings at all that should have prevented it.

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.

I installed them back in the reverse order and the issue re-appeared with the first two add-ons (i.e. – the last two I removed). I narrowed this down to the exact add-ons and did some Internet searching. As it happens it was a minor known issue with that add-ons and some JavaScript implementations.

Add-ons are immensely powerful but they can interfere with functionality.

Useful Hint
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.

Useful Links
How to manage add-ons across multiple machines -

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