Hi Mickael,
> As I'm working on TextMate and Language Server, I have the impression that using TestMate grammars and a _javascript_ language server such as the one embedded in VSCode can lead to very good results in term of JS edition.
Totally agree with you! I have followed this idea with typescript.java by consuming tsserver and it works with _javascript_ only too. You can try typescript.java which provides a custom "_javascript_ (Salsa) Editor" which consumes TextMate and tsserver and it works well: completion, hover, outline, hyperlink, validation, references, etc. ) Performance are very good. IMHO completion is more advanced than JSDT (Thank to TypeScript tsserver).
> This combo could do most of the work, and the internal JSDT model would still be useful for advanced operations not covered by the VSCode Language Server for JS.
I tell me which advanced operations, are you speaking?
> However, I'm wondering how much the Node/JS debuggers in Eclipse IDE do rely on the JSDT internal model for JS files. Do they integrate with the AST/DOM, or do they remain at text level (so they could easily be used together with a totally different editor)?
Regard's Angelo