I recently got multiple questions regarding auto-completion in JS scripts in medini. Its not working in newer releases and seems to be broken. We rely here heavily on the JavaScript Development Tools (JSDT) project which is part of a more broader WTP (Web Tools Platform) project in the Eclipse ecosystem.
It seems that the auto-completion got broken when we moved from Eclipse Mars to Oxygen a while back. Unfortunately the reported issue is still open (see https://bugs.eclipse.org/bugs/show_bug.cgi?id=504057)
The workarounds mentioned there and in other places does not work for me.
I'll keep you updated
Jan