Add another test case for generics (#322)

Add another test case for generics

Author: dwijnand

core/src/main/scala/com/typesafe/tools/mima/core/Problems.scala

@@ -109,8 +109,10 @@ case class IncompatibleResultTypeProblem(oldmeth: MemberInfo, newmeth: MemberInf
  */
 case class IncompatibleSignatureProblem(oldmeth: MemberInfo, newmeth: MemberInfo) extends MemberProblem(oldmeth) {
   def description = affectedVersion => {
-    oldmeth.methodString + " has a different signature in " + affectedVersion + " version, where it is " + newmeth.signature +
-       " rather than " + oldmeth.signature
+    // a method that takes no parameters and returns Object can have no signature
+    def orNA(s: String) = if (s.isEmpty) "[N/A]" else s
+    s"${oldmeth.methodString} has a different signature in $affectedVersion version, " +
+      s"where it is ${orNA(newmeth.signature)} rather than ${orNA(oldmeth.signature)}"
   }
 }
 

functional-tests/src/test/class-constructor-generics-nok/problems.txt

@@ -0,0 +1,3 @@
+method source()scala.Tuple2 in class OptionPane has a different signature in new version, where it is ()Lscala/Tuple2<LMyPane<TA;>;Ljava/lang/String;>; rather than ()Lscala/Tuple2<Ljavax/swing/JOptionPane;Ljava/lang/String;>;
+method show()java.lang.Object in class OptionPane has a different signature in new version, where it is ()TA; rather than [N/A]
+method this(scala.Tuple2)Unit in class OptionPane has a different signature in new version, where it is (Lscala/Tuple2<LMyPane<TA;>;Ljava/lang/String;>;)V rather than (Lscala/Tuple2<Ljavax/swing/JOptionPane;Ljava/lang/String;>;)V

functional-tests/src/test/class-constructor-generics-nok/v1/A.scala

@@ -0,0 +1,10 @@
+trait DialogSource[+A] { def show(): A }
+
+final class OptionPane(val source: (javax.swing.JOptionPane, String)) extends DialogSource[Any] {
+  def show(): Any = {
+    val (pane, title) = source
+    val jdlg = pane.createDialog(title)
+    jdlg.setVisible(true)
+    pane.getValue
+  }
+}

functional-tests/src/test/class-constructor-generics-nok/v2/A.scala

@@ -0,0 +1,15 @@
+trait DialogSource[+A] { def show(): A }
+
+final class OptionPane[A](val source: (MyPane[A], String)) extends DialogSource[A] {
+  def show(): A = {
+    val (pane, title) = source
+    val jdlg = pane.peer.createDialog(title)
+    jdlg.setVisible(true)
+    pane.result
+  }
+}
+
+trait MyPane[A] {
+  def peer: javax.swing.JOptionPane
+  def result: A
+}