Converting varargs Java to Scala flags

[jrudolph]

Converting a Java class with varargs to Scala, mima doesn't seem to know about bridge methods created by the Scala @varargs annotation:

v1:

public class A {
    public static String create(String... args) {
        return null;
    }
}

v2:

import scala.annotation.varargs

object A {
  @varargs
  def create(args: String*): String = null
}
class A

Test here: https://github.com/lightbend/migration-manager/compare/master...jrudolph:show-varargs-issue?expand=1

[dwijnand]

Interesting. From diffing the bytecode it looks everything is the same:

diff --git a/A.class b/A.class
index 3804de7..850724c 100644
--- a/A.class
+++ b/A.class
@@ -1,15 +1,23 @@

-Compiled from "A.java"
+Compiled from "A.scala"
 public class A {
+  public static java.lang.String create(java.lang.String...);
+    descriptor: ([Ljava/lang/String;)Ljava/lang/String;
+    Code:
+##: getstatic     ###                 // Field A$.MODULE$:LA$;
+##: invokevirtual ###                 // Method A$.create:([Ljava/lang/String;)Ljava/lang/String;
+##: areturn
+
+  public static java.lang.String create(scala.collection.Seq<java.lang.String>);
+    descriptor: (Lscala/collection/Seq;)Ljava/lang/String;
+    Code:
+##: getstatic     ###                 // Field A$.MODULE$:LA$;
+##: invokevirtual ###                 // Method A$.create:(Lscala/collection/Seq;)Ljava/lang/String;
+##: areturn
+
   public A();
     descriptor: ()V
     Code:
 ##: invokespecial ###                 // Method java/lang/Object."<init>":()V
 ##: return
-
-  public static java.lang.String create(java.lang.String...);
-    descriptor: ([Ljava/lang/String;)Ljava/lang/String;
-    Code:
-##: aconst_null
-##: areturn
 }

[jrudolph]

Yeah, exactly, that's the weird thing.