[CodeCompletion] Add a regression test for SR-2560

[AnthonyLatsis]

сс @rintaro

SR-2560 seems to have been unknowingly fixed.

[rintaro]

Thank you!

[rintaro]

@swift-ci Please smoke test

[AnthonyLatsis]

Although the way it prints doesn't perfectly match the requirement's generic signature style. Do you think we should always make sure to perfectly match the style of the base declaration?

[rintaro]

I don't think they should perfectly match.
But ideally, I think, we should keep constraints position (generic params or where clause).
So in this case,

    foo<S: Sequence>(x: S) where S.Element == Int {
        <#code#>
    }

is preferable because the original : Sequence constraint is in the generic param clause.

[AnthonyLatsis]

Yes, agreed.

I am going to work on SR-9560 soon; taking advantage of the moment, could you hint me where to look at for how ↵(enter) actions on placeholders are implemented?

[rintaro]

@AnthonyLatsis Commented in SR-9560 👍