Code not compiling when Unit-returning SAM and overloaded methods involved

I think there seems to be a problem with SAM conversions and choosing the right overloaded method. Sorry if the bug already exists I couldn’t find one.

Compiler version

Scala 3.0.2 and 3.1.0-RC2

Minimized code

You can find a reproducer here: https://github.com/jlprat/overload-sam-reproducer/

import java.lang.Throwable
import java.util.function.Supplier

object Reproducer {
  
  //assertThrows has 3 overloads, 2 with 3 parameters and 1 with only 2 parameters.

  //This overload is taking a subclasss of `Throwable`, and an `Executable` which is a parameterless SAM returning void
  assertThrows(classOf[IllegalArgumentException], () => 3)
  
  //This overload is taking a subclasss of `Throwable`, an `Executable` which is a parameterless SAM returning void, and a `String`
  assertThrows(classOf[IllegalArgumentException], () => 3, "This is a message")

  //This overload is taking a subclasss of `Throwable`, an `Executable` which is a parameterless SAM returning void, and a `Supplier` returning `String`
  assertThrows(classOf[IllegalArgumentException], () => 3, () => "This is a message")

  def assertThrows[T <: Throwable](clazz: Class[T], executable: Executable): Unit = ???

  def assertThrows[T <: Throwable](clazz: Class[T], executable: Executable, message: String): Unit = ???

  def assertThrows[T <: Throwable](clazz: Class[T], executable: Executable, supplier: Supplier[String]): Unit = ???

  @FunctionalInterface
  trait Executable {
    @throws[Throwable]
    def execute(): Unit
  }

}

Output

[warn] -- [E129] Potential Issue Warning: /home/josep.prat/playground/overload-sam-reproducer/src/main/scala/example/Reproducer.scala:11:56
[warn] 11 |  assertThrows(classOf[IllegalArgumentException], () => 3)
[warn]    |                                                        ^
[warn]    |A pure expression does nothing in statement position; you may be omitting necessary parentheses
[error] -- [E134] Type Error: /home/josep.prat/playground/overload-sam-reproducer/src/main/scala/example/Reproducer.scala:14:2
[error] 14 |  assertThrows(classOf[IllegalArgumentException], () => 3, "This is a message")
[error]    |  ^^^^^^^^^^^^
[error]    |None of the overloaded alternatives of method assertThrows in object Reproducer with types
[error]    | [T <: Throwable]
[error]    |  (clazz: Class[T], executable: example.Reproducer.Executable, supplier:
[error]    |    java.util.function.Supplier[String]
[error]    |  ): Unit
[error]    | [T <: Throwable]
[error]    |  (clazz: Class[T], executable: example.Reproducer.Executable, message: String
[error]    |    ):
[error]    |  Unit
[error]    | [T <: Throwable]
[error]    |  (clazz: Class[T], executable: example.Reproducer.Executable): Unit
[error]    |match arguments ((classOf[IllegalArgumentException] : Class[IllegalArgumentException]), () => Int, ("This is a message" : String))
[error] -- [E134] Type Error: /home/josep.prat/playground/overload-sam-reproducer/src/main/scala/example/Reproducer.scala:17:2
[error] 17 |  assertThrows(classOf[IllegalArgumentException], () => 3, () => "This is a message")
[error]    |  ^^^^^^^^^^^^
[error]    |None of the overloaded alternatives of method assertThrows in object Reproducer with types
[error]    | [T <: Throwable]
[error]    |  (clazz: Class[T], executable: example.Reproducer.Executable, supplier:
[error]    |    java.util.function.Supplier[String]
[error]    |  ): Unit
[error]    | [T <: Throwable]
[error]    |  (clazz: Class[T], executable: example.Reproducer.Executable, message: String
[error]    |    ):
[error]    |  Unit
[error]    | [T <: Throwable]
[error]    |  (clazz: Class[T], executable: example.Reproducer.Executable): Unit
[error]    |match arguments ((classOf[IllegalArgumentException] : Class[IllegalArgumentException]), () => Int, () => String)

Expectation

Code should compile

[smarter]

Thanks, this is great!

[jlprat]

Thread created under https://contributors.scala-lang.org/t/code-not-compiling-when-unit-returning-sam-and-overloaded-methods-involved/5271