Go to Implementation doesn't find anonymous instantiations with SAM conversion

[filipwiech]

Describe the bug

Recently I was confused as Metals couldn't find any implementation of a type in the project, even thought it had to be used somewhere. Turns out that Go to Implementation is unable to find anonymous instantiations if SAM conversion is applied. Example, only test3 and test4 are shown when trying to search for the MyTestTrait implementations:

// applies to abstract classes too
trait MyTestTrait {
  def compute(input: Int): Int
}

// MyTestObject could be a class, trait, etc.
object MyTestObject {

  val test1: MyTestTrait = (input: Int) => input + 1
  def test2: MyTestTrait = (input: Int) => input + 2

  val test3: MyTestTrait = new MyTestTrait {
    def compute(input: Int): Int = input + 3
  }
  def test4: MyTestTrait = new MyTestTrait {
    def compute(input: Int): Int = input + 4
  }

}

Tested on Scala 2.13.

Expected behavior

All implementations are shown by Metals, including the test1 and test2 in the provided code sample.

Operating system

Linux

Editor/Extension

VS Code

Version of Metals

1.1.0+100-58b80be5-SNAPSHOT

Extra context or search terms

go to implementation, SAM, anonymous type, class, trait

[kasiaMarek]

Thanks for the report. Go to implementation bases on SemanticDB, which doesn't produce an anonymous class for SAM conversion both in Scala 2 and Scala 3.

[tgodzik]

We also have an issue already about that, but thanks for reminding us! #4596

[filipwiech]

@kasiaMarek Thank you for the explanation! 👍 Is there an upstream ticket that could be tracked? 🙂
@tgodzik Oops, sorry about that, my bad for not noticing this earlier. I had filed the issue late at night after getting a reproduction and haven't thought to check. 😅

[tgodzik]

I raised it in scalameta/scalameta#3394