KJS: don't copy members from native interfaces

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BoxJsTestGenerated.java

@@ -3437,6 +3437,12 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
             doTest(fileName);
         }
 
+        @TestMetadata("fromNativeInterface.kt")
+        public void testFromNativeInterface() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/box/inheritance/fromNativeInterface.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("inheritFromCharIterator.kt")
         public void testInheritFromCharIterator() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/box/inheritance/inheritFromCharIterator.kt");

js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/InterfaceFunctionCopier.kt

@@ -22,6 +22,7 @@ import com.google.dart.compiler.backend.js.ast.JsNameRef
 import org.jetbrains.kotlin.backend.common.bridges.generateBridgesForFunctionDescriptor
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.js.translate.context.StaticContext
+import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils.isNativeObject
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils.prototypeOf
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils.pureFqn
@@ -43,6 +44,9 @@ class InterfaceFunctionCopier(val context: StaticContext) {
     }
 
     private fun addInterfaceDefaultMembers(descriptor: ClassDescriptor, context: StaticContext) {
+        // optimization: don't do anything for native declarations
+        if (isNativeObject(descriptor)) return
+
         val classModel = ClassModel(descriptor)
         classModels[descriptor] = classModel
 
@@ -60,7 +64,7 @@ class InterfaceFunctionCopier(val context: StaticContext) {
         }
 
         val superModels = DescriptorUtils.getSuperclassDescriptors(descriptor)
-                .filter { it.kind == ClassKind.INTERFACE }
+                .filter { it.kind == ClassKind.INTERFACE && !isNativeObject(it) }
                 .map { classModels[it]!! }
         for (superModel in superModels) {
             for (name in superModel.copiedFunctions) {

js/js.translator/testData/box/inheritance/fromNativeInterface.kt

@@ -0,0 +1,15 @@
+package foo
+
+@native
+interface A {
+    val bar: Int get() = noImpl
+    fun foo(): String = noImpl
+}
+
+class C : A
+
+fun box(): String {
+    val c = C()
+
+    return "OK"
+}