[JS IR] Don't generate "import" statements for external interfaces

#KT-40964 fixed

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrModuleToJsTransformer.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -15,11 +15,10 @@ import org.jetbrains.kotlin.ir.backend.js.export.ExportedModule
 import org.jetbrains.kotlin.ir.backend.js.export.toTypeScript
 import org.jetbrains.kotlin.ir.backend.js.lower.StaticMembersLowering
 import org.jetbrains.kotlin.ir.backend.js.utils.*
-import org.jetbrains.kotlin.ir.declarations.IrDeclarationWithName
+import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
-import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
-import org.jetbrains.kotlin.ir.declarations.path
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.util.isEffectivelyExternal
+import org.jetbrains.kotlin.ir.util.isInterface
 import org.jetbrains.kotlin.js.backend.ast.*
 import org.jetbrains.kotlin.js.config.JSConfigurationKeys
 import org.jetbrains.kotlin.utils.DFS
@@ -358,6 +357,7 @@ class IrModuleToJsTransformer(
             file.declarations
                 .asSequence()
                 .filterIsInstance<IrDeclarationWithName>()
+                .filter { !(it is IrClass && it.isInterface && it.isEffectivelyExternal()) }
                 .forEach { declaration ->
                     val declName = getNameForExternalDeclaration(declaration)
                     importStatements.add(

js/js.tests/test/org/jetbrains/kotlin/js/test/es6/semantics/IrBoxJsES6TestGenerated.java

@@ -5232,6 +5232,11 @@ public class IrBoxJsES6TestGenerated extends AbstractIrBoxJsES6Test {
             runTest("js/js.translator/testData/box/jsModule/importCountUmd.kt");
         }
 
+        @TestMetadata("interfaces.kt")
+        public void testInterfaces() throws Exception {
+            runTest("js/js.translator/testData/box/jsModule/interfaces.kt");
+        }
+
         @TestMetadata("topLevelVarargFun.kt")
         public void testTopLevelVarargFun() throws Exception {
             runTest("js/js.translator/testData/box/jsModule/topLevelVarargFun.kt");
@@ -5333,6 +5338,11 @@ public class IrBoxJsES6TestGenerated extends AbstractIrBoxJsES6Test {
             runTest("js/js.translator/testData/box/jsQualifier/classes.kt");
         }
 
+        @TestMetadata("interfaces.kt")
+        public void testInterfaces() throws Exception {
+            runTest("js/js.translator/testData/box/jsQualifier/interfaces.kt");
+        }
+
         @TestMetadata("simple.kt")
         public void testSimple() throws Exception {
             runTest("js/js.translator/testData/box/jsQualifier/simple.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrBoxJsTestGenerated.java

@@ -5232,6 +5232,11 @@ public class IrBoxJsTestGenerated extends AbstractIrBoxJsTest {
             runTest("js/js.translator/testData/box/jsModule/importCountUmd.kt");
         }
 
+        @TestMetadata("interfaces.kt")
+        public void testInterfaces() throws Exception {
+            runTest("js/js.translator/testData/box/jsModule/interfaces.kt");
+        }
+
         @TestMetadata("topLevelVarargFun.kt")
         public void testTopLevelVarargFun() throws Exception {
             runTest("js/js.translator/testData/box/jsModule/topLevelVarargFun.kt");
@@ -5333,6 +5338,11 @@ public class IrBoxJsTestGenerated extends AbstractIrBoxJsTest {
             runTest("js/js.translator/testData/box/jsQualifier/classes.kt");
         }
 
+        @TestMetadata("interfaces.kt")
+        public void testInterfaces() throws Exception {
+            runTest("js/js.translator/testData/box/jsQualifier/interfaces.kt");
+        }
+
         @TestMetadata("simple.kt")
         public void testSimple() throws Exception {
             runTest("js/js.translator/testData/box/jsQualifier/simple.kt");

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

@@ -5247,6 +5247,11 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
             runTest("js/js.translator/testData/box/jsModule/importCountUmd.kt");
         }
 
+        @TestMetadata("interfaces.kt")
+        public void testInterfaces() throws Exception {
+            runTest("js/js.translator/testData/box/jsModule/interfaces.kt");
+        }
+
         @TestMetadata("topLevelVarargFun.kt")
         public void testTopLevelVarargFun() throws Exception {
             runTest("js/js.translator/testData/box/jsModule/topLevelVarargFun.kt");
@@ -5348,6 +5353,11 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
             runTest("js/js.translator/testData/box/jsQualifier/classes.kt");
         }
 
+        @TestMetadata("interfaces.kt")
+        public void testInterfaces() throws Exception {
+            runTest("js/js.translator/testData/box/jsQualifier/interfaces.kt");
+        }
+
         @TestMetadata("simple.kt")
         public void testSimple() throws Exception {
             runTest("js/js.translator/testData/box/jsQualifier/simple.kt");

js/js.translator/testData/box/jsModule/interfaces.kt

@@ -0,0 +1,49 @@
+// EXPECTED_REACHABLE_NODES: 1238
+// MODULE_KIND: COMMON_JS
+// FILE: bar.kt
+@file:JsModule("lib")
+@file:JsQualifier("foo")
+package foo
+
+external interface Bar {
+    fun ping(): String
+}
+
+// FILE: baz.kt
+@file:JsModule("lib")
+package boo
+
+external interface Baz {
+    fun pong(): Int
+}
+
+// FILE: root.kt
+@file:JsModule("lib")
+import foo.Bar
+import boo.Baz
+
+external val bar: Bar
+external val baz: Baz
+
+// FILE: test.kt
+fun box(): String {
+    if (bar.ping() != "ping" || baz.pong() != 194) return "Fail"
+
+    return "OK"
+}
+
+// FILE: test.js
+$kotlin_test_internal$.beginModule();
+module.exports = {
+    bar : {
+        ping() {
+            return "ping"
+        }
+    },
+    baz : {
+        pong() {
+            return 194
+        }
+    }
+};
+$kotlin_test_internal$.endModule("lib");

js/js.translator/testData/box/jsQualifier/interfaces.kt

@@ -0,0 +1,43 @@
+// EXPECTED_REACHABLE_NODES: 1238
+// FILE: bar.kt
+@file:JsQualifier("foo")
+package foo
+
+external interface Bar {
+    fun ping(): String
+}
+
+// FILE: baz.kt
+package boo
+
+external interface Baz {
+    fun pong(): Int
+}
+
+// FILE: root.kt
+import foo.Bar
+import boo.Baz
+
+external val bar: Bar
+external val baz: Baz
+
+// FILE: test.kt
+fun box(): String {
+    if (bar.ping() != "ping" || baz.pong() != 194) return "Fail"
+
+    return "OK"
+}
+
+// FILE: test.js
+
+var bar = {
+    ping() {
+        return "ping"
+    }
+};
+
+var baz = {
+    pong() {
+        return 194
+    }
+};