where statement for type parameters supported in class and trait declaration

src/org/jetbrains/jet/j2k/ast/Class.java

@@ -29,6 +29,24 @@ public class Class extends Node {
     myFields = fields;
   }
 
+  private boolean hasWhere() {
+    for (Element t : myTypeParameters)
+      if (t instanceof TypeParameter && ((TypeParameter)t).hasWhere())
+        return true;
+    return false;
+  }
+
+  String typeParameterWhereToKotlin() {
+    if (hasWhere()) {
+      List<String> wheres = new LinkedList<String >();
+      for (Element t : myTypeParameters)
+        if (t instanceof TypeParameter)
+          wheres.add(((TypeParameter)t).getWhereToKotlin());
+      return SPACE + "where" + SPACE + AstUtil.join(wheres, COMMA_WITH_SPACE) + SPACE;
+    }
+    return EMPTY;
+  }
+
   @NotNull
   List<Function> methodsExceptConstructors() {
     final LinkedList<Function> result = new LinkedList<Function>();
@@ -55,7 +73,10 @@ public class Class extends Node {
   @NotNull
   @Override
   public String toKotlin() {
-    return TYPE + SPACE + myName.toKotlin() + typeParametersToKotlin() + implementTypesToKotlin() + SPACE + "{" + N +
+    return TYPE + SPACE + myName.toKotlin() + typeParametersToKotlin() +
+      implementTypesToKotlin() +
+      typeParameterWhereToKotlin() +
+      SPACE + "{" + N +
       AstUtil.joinNodes(myFields, N) + N +
       AstUtil.joinNodes(methodsExceptConstructors(), N) + N +
       AstUtil.joinNodes(myInnerClasses, N) + N +

test/org/jetbrains/jet/j2k/ast/TypeParametersTest.java

@@ -36,4 +36,56 @@ public class TypeParametersTest extends JetTestCaseBase {
       "fun max<T : Object?, K : Node?>(coll : Collection<out T?>?) : T? where T : Comparable<in T?>?, K : Collection<in K?>? { }"
     );
   }
+
+  public void testClassDoubleParametrizationWithTwoBoundsWithExtending() throws Exception {
+    Assert.assertEquals(
+      classToSingleLineKotlin("final class CC <T extends INode & Comparable<? super T>, K extends Node & Collection<? super K>> extends A {}"),
+      "class CC<T : INode?, K : Node?> : A where T : Comparable<in T?>?, K : Collection<in K?>? { }"
+    );
+  }
+
+  public void testTraitDoubleParametrizationWithTwoBoundsWithExtending() throws Exception {
+    Assert.assertEquals(
+      classToSingleLineKotlin(
+        "interface I <T extends INode & Comparable<? super T>, K extends Node & Collection<? super K>> extends II {}"),
+      "trait I<T : INode?, K : Node?> : II where T : Comparable<in T?>?, K : Collection<in K?>? { }"
+    );
+  }
+
+  public void testGenericClass() throws Exception {
+    Assert.assertEquals(
+      classToSingleLineKotlin("final class Comparable<T> {}"),
+      "class Comparable<T> { }"
+    );
+  }
+
+  public void testComplexExampleWithClassExtending() throws Exception {
+    Assert.assertEquals(
+      classToSingleLineKotlin(
+        "interface CommandHandler<T extends Command> {}"),
+      "trait CommandHandler<T : Command?> { }"
+    );
+  }
+
+  public void testClassParametrizationWithTwoBounds() throws Exception {
+    Assert.assertEquals(
+      classToSingleLineKotlin("final class C<T extends INode & Comparable<? super T>> {}"),
+      "class C<T : INode?> where T : Comparable<in T?>? { }"
+    );
+  }
+
+  public void testClassParametrizationWithTwoBoundsWithExtending() throws Exception {
+    Assert.assertEquals(
+      classToSingleLineKotlin("final class C<T extends INode & Comparable<? super T>> extends A {}"),
+      "class C<T : INode?> : A where T : Comparable<in T?>? { }"
+    );
+  }
+
+  public void testComplexExampleWithClassMultiplyExtending() throws Exception {
+    Assert.assertEquals(
+      classToSingleLineKotlin(
+        "interface CommandHandler<T extends INode, String> {}"),
+      "trait CommandHandler<T : INode?, String> { }"
+    );
+  }
 }