Autocomplete at end of line with whitespace

[adampauls]

Describe the bug

With this prefix:

object Test:
  case class Widget(name: String, other: Int)
  val otxxx: Int = 1
  Widget(name = "foo", 

autocomplete will (correctly) suggest both otxxx and other if either (a) the cursor is immediately after the comma, or (b) there is another line (like val x = 5) after the Widget line.

I think this might be a bug in the underlying Scala parser, but I am not sure.

Expected behavior

Autocomplete should behave the same regardless of whitespace in this case.

Operating system

macOS

Editor/Extension

VS Code

Version of Metals

v1.12.0

Extra context or search terms

No response

[tgodzik]

Thanks for reporting! Suprisingly, if you start writing o it will also suggest the correct completions. I think this is one of the cases that we might need to add the artificial CURSOR name so that the parser doesn't fail. It's something we haven't yet ported from Scala 2.

[adampauls]

Hmm, actually, now I'm confused. Look at what I believe are dotty's completion unit tests, there are no unit tests for filling in arguments to an Apply, i.e. nothing like foo(${m1}. Does the functionality for filling in argument names and values by type live only in Metals? If so, can I have a good pointer? If not, do you know where it dotty it is tested?

[adampauls]

Ah, I found this, so it seems that the Scala compiler only provides some of the completions functionality.

[tgodzik]

We do a number of custom completions that are built upon the information from the Dotty presentation compiler. We try to port some of the improvements to the compiler itself, but since that can be used by a number of different tools we need to be careful what we include upstream.