Firefox Web Extension "selectionchange"

I'm trying to write cross browser Web Extension. Based on selected value on web page I want to create appropriate entry in context menu. I created a sample code to check if browse

Solution 1:

I believe selectionchange is still hidden behind a flag in Firefox... open up about:config and search for dom.select_events.enabled ... it defaults to false, change it to true and restart the browser and give it another whirl.