"Find All References" does not work on extension methods

[strelec]

Describe the bug

In the snippet below, if you search for usages of extension method Deck.size(), Metals only finds the local usage in fooSize, but ignores usages in other classes and files.

opaque type Deck = Long

object Deck {
	extension (data: Deck) {
		def size: Int = java.lang.Long.bitCount(data)
		def fooSize: Int = size
	}
}

Expected behavior

"Find All References" finds references across the whole project.

Operating system

Linux

Editor/Extension

VS Code

Version of Metals

v1.0.0 (newest version)

Extra context or search terms

No response

[strelec]

I think the problem is likely the opaque type, not the extension method.

[tgodzik]

Thanks for reporting! This might need some fixes in the compiler itself as the semanticdb document is generated there. I will raise a new issue there.

[tgodzik]

Actually, coming back to this and trying to reproduce it I am unable to do that.

object Main {
  import Deck._
  val deck: Deck = ???
  println(deck.size)
  println(deck.fooSize)
}

works ok, do you have any examples?

[kpodsiad]

@tgodzik try without importing Deck._ as it brings extension method explicitly into the scope, but it should be there already as it is defined in companion object. If you put Main in the same package as Deck (so it is possible to access it), then semanticDB is not properly generated.

object Main {
  val deck: Deck = ???
  println(deck.size)
  println(deck.fooSize)
}

[strelec]

How log ago was this bug introduced?

Because searching for references in extension methods has never worked for me, for many Scala releases.

[kpodsiad]

@strelec I assume that it was simply always not working ;)

[tgodzik]

This seems to be a bug in the compiler, but should be fixed in the next release scala/scala3#18557