To properly test a custom event you will need to take some steps to make sure you don’t miss them because of a browser redirect.
Go to the page that the custom event happens on.
Right-click and open the Web Inspector
Go to the Network Tab in the Inspector
Click the Throttling drop down and set it to “Offline” or check the “Offline” tickbox
Go to the “Console” tab inside the inspector window and type bwai.debug = true and hit return
Minimize or move out of the Inspector
Complete the action that should trigger the custom event
Now go back to the inspector and read the output looking for the event text in the case of item added to the basket you’re looking for “add to basket item triggered”
A quick run though video showing all the steps above can be found at