Improve chain completions

[gayanper]

The PR improve how the chain completions are transformed into CompletionItems by

• Reusing the same logic which is used for normal completions with minor modifications to support special cases in chain completions.
• This change add support for javadoc on the chain completion edge symbol as well.
• Add more unit tests for chain completions.

[gayanper]

@snjeza @rgrunber Let me know what you think

[gayanper]

@rgrunber what do think about this change ?

[gayanper]

@rgrunber WDYT about this PR ?

[rgrunber]

I think it should be fine to customize the chain completion rendering with this logic. The only part that I would want to look closely at is the isChainCompletion check. Is it really the case that no other completions have dots that would wrongly be included in this ? Also chain completions are generated as CompletionItem. CompletionProposal comes from the underlying completion engine, and I don't think they would ever show up there. I'd have to have a look.

[gayanper]

Also chain completions are generated as CompletionItem. CompletionProposal comes from the underlying completion engine, and I don't think they would ever show up there. I'd have to have a look.

This was done to reuse the existing logic for creating the completion rendering. Since the existing login in so closely tight with CompletionProposal I decided to use them even though I'm also not happy with that decision.

We could of course decouple completion item rendering logic from CompletionProposal by extracting a contract for required information and decorating the CompletionProposal from underlying completion engine. This will provide us the opportunity to do the same with chain completions without trying to create CompletionProposals for them.

Do you think that kind of a change will be beneficial for JDT.LS ?

[gayanper]

@rgrunber any feedback ?

[rgrunber]

@gayanper , can this change be closed or is there something here still needing to be merged ?

[gayanper]

@gayanper , can this change be closed or is there something here still needing to be merged ?

I will check and get back. I need to check if javadoc is working with what we have right now.

[gayanper]

@rgrunber I think we can close this and I did accidentally closed it mixing up with a another PR, but I now confirmed that this PR is not needed anymore.