Quick fix "Import" does not work for modifier private with access qualifier

[tgodzik]

Discussed in #6730

^{Originally posted by LeUser111 August 28, 2024}
Hi there,

I'm making massive use of access modifiers in combination with access qualifiers (see Scala 2 language specification) throughout my code bases.

Unfortunately, metals does not suggest imports for members with modifier private and matching qualifier.

A simple example would be:

package com.airhack.a

private[airhack] object A {
  
    val hello = "hello"

}

package com.airhack.b

object B {
  
    // A is missing the import, metals doesn't suggest importing A, even though the import would be valid
    val hello = A.hello

}

The import quick fix works perfectly fine when A is public. Right now this means that I have to write a lot of imports by hand. It would be really nice if metals could suggest the imports automatically!

I'm not sure if this would be a bug or feature request and whether metals is even the right project - it might be an upstream issue.

I'd be grateful if someone could point me in the right direction!

[masonedmison]

Has anyone started looking at this one yet? If not, I'd be happy to take a look at this.

[tgodzik]

I don't think anyone had the time, so you're welcome to take a look.

Some places to take a look at:

• https://github.com/scalameta/metals/blob/main/mtags/src/main/scala-2/scala/meta/internal/pc/AutoImportsProvider.scala

This one is used for the auto imports code action.

• https://github.com/scalameta/metals/blob/main/mtags/src/main/scala-2/scala/meta/internal/pc/WorkspaceSymbolSearch.scala#L152

We used this one to get members to import found from indexing via metals.

• metals/metals/src/main/scala/scala/meta/internal/metals/WorkspaceSearchVisitor.scala

  Line 29 in f3657de

  class WorkspaceSearchVisitor(

Here we provide the potential matches

[masonedmison]

Thanks @tgodzik! I believe I've found in the code where symbols are being filtered by visibility. It looks like something similar is done in the scala 3 implementation.

I'll have to have a deeper look into the scala reflection documentation (I can start with scala 2 if that's OK with you) to get a better sense on how to get the "access" modifier from a Symbol.

[tgodzik]

Actually, this might be as simple as doing sym.isPublic || sym.hasAccessBoundary, from what I see we do check accessibility anyway later on.

You could just try that with some tests for good measure.

[masonedmison]

@tgodzik I made a bit of progress on this and opened up a draft PR. If we like this approach, it should be fairly easy to take a similar approach for the Scala 3 AutoImportsProvider implementation.