Thanks, Angelo. But respectfully, I'm really hoping there will be other suggestions.
Your suggestion hasn't been tested. That leaves a lot to my "tier". I'm not competent to experiment with Typescript Plus your FOSS and the other tool. Also if something doesn't work I'm left with two More
uncertain links in the tool chain where I'm not sure where problems lie
or where to go for help.
And adding the typescript tier doesn't work well for a scenario where common FOSS is being maintained by a group of contributors. It's already tough to have a FOSS project which "sort of" mandates a tool chain including Eclipse, Ant, Tern, JSDoc, and Node.JS. And while it may be possible to use Rhino with Java 1.7 with all this, I think we need to push forward and mandate Nashorn via 1.8. (Hope I got that right.) So, building the toolkit is already a huge undertaking and adding more to the pile takes a lot of valuable resources away from the bottom line which is facilitating the creation of end-user applications.
That said, I understand that if I want strong type suggestions for Java modules in JS then it's reasonable to suggest a tool like Typescript. So I'll keep this on the table while considering other suggestions. Someone else here might tell me to suck it up and use what's recommended in the spirit of Free and Open Source. That might ultimately be the way to go. But is this the "official" direction of Eclipse and the WTP, where there is a defined limit to the capabilities and to go further other tools are recommended? I'm looking to understand where those lines are drawn.