import `export`ed function from another file lose default parameters

[liewhite]

Compiler version

3.1.2

Minimized code

from/E.scala

package from

object E {
  def toStr(b: Boolean = true) = {
    b.toString
  }
}

export E.toStr

main.scala

import from.toStr

@main def exportBug = {
  toStr()               //missing argument for parameter b of method toStr in package from: (b: Boolean): String
}

Output

compile error: missing argument for parameter b of method toStr in package from: (b: Boolean): String

Missing default parameters may be a compiler bug?

[pikinier20]

Log from scala-cli:

Compiling project (Scala 3.1.1, JVM)
[error] ./f2.scala:4:3: missing argument for parameter b of method toStr in package from: (b: Boolean): String
[error]   toStr()               //missing argument for parameter b of method toStr in package from: (b: Boolean): String
[error]   ^^^^^^^
Error compiling project (Scala 3.1.1, JVM)
Compilation failed
➜  i15031 scala-cli compile . -S 3.nightly
Downloading Scala 3.2.0-RC1-bin-20220425-ba8dccb-NIGHTLY compiler
Compiling project (Scala 3.2.0-RC1-bin-20220425-ba8dccb-NIGHTLY, JVM)
Compiled project (Scala 3.2.0-RC1-bin-20220425-ba8dccb-NIGHTLY, JVM)
➜  i15031 scala-cli compile . -S 3.1.2    
Compiling project (Scala 3.1.2, JVM)
Compiled project (Scala 3.1.2, JVM)

Seems like this bug has been fixed already. Interestingly, on my side it compiled on 3.1.2 but didn't compile on 3.1.1

[pikinier20]

3.1.2 introduced #14051 which most likely fixed the bug

[liewhite]

3.1.2 introduced #14051 which most likely fixed the bug

I use sbt, i'm sure scala version is 3.1.2.

build.sbt

val scala3Version = "3.1.2"

lazy val root = project
  .in(file("."))
  .settings(
    name := "playground",
    version := "0.1.0-SNAPSHOT",

    scalaVersion := scala3Version,
  )

sbt compile command output:

sbt:playground> compile
[info] compiling 1 Scala source to /Users/lee/repos/scala/playground/target/scala-3.1.2/classes ...
[error] -- Error: /Users/lee/repos/scala/playground/src/main/scala/exportBug.scala:4:15 
[error] 4 |  println(toStr())
[error]   |          ^^^^^^^
[error]   |missing argument for parameter b of method toStr in package from: (b: Boolean): String
[error] one error found
[error] (Compile / compileIncremental) Compilation failed

[pikinier20]

The println surrounding the toStr() is crucial. You didn't provide it in minimized example but right now I see it in your compiler log.

I agree, it fails on 3.1.2. Still, it doesn't on newest nightly.

EDIT:
To be sure, I tested in on both scala-cli and sbt, and for the fact got sometimes compilation error on 3.1.2 but it might be related to incremental compilation. Making a clean build always succeeds on 3.1.2 and newest nightly.

Could you try to verify that?

[liewhite]

The println surrounding the toStr() is crucial. You didn't provide it in minimized example but right now I see it in your compiler log.

I agree, it fails on 3.1.2. Still, it doesn't on newest nightly.

EDIT: To be sure, I tested in on both scala-cli and sbt, and for the fact got sometimes compilation error on 3.1.2 but it might be related to incremental compilation. Making a clean build always succeeds on 3.1.2 and newest nightly.

Could you try to verify that?

Oh, it works with sbt clean compile, tks, i'll close this issue

[pikinier20]

I think we can reopen that as a bug in incremental compilation. It doesn't work very well with exports.

Probably this issue is related to: #11841 .