JS: prohibit to implement functional interfaces. See KT-15136

compiler/testData/codegen/box/functions/invoke/kt3190.kt

@@ -1,4 +1,6 @@
 //KT-3190 Compiler crash if function called 'invoke' calls a closure
+// IGNORE_BACKEND: JS
+// JS backend does not allow to implement Function{N} interfaces
 
 fun box(): String {
     val test = Cached<Int,Int>({ it + 2 })

compiler/testData/codegen/box/functions/invoke/kt3822invokeOnThis.kt

@@ -1,4 +1,6 @@
 //KT-3822 Compiler crashes when use invoke convention with `this` in class which extends Function0<T>
+// IGNORE_BACKEND: JS
+// JS backend does not allow to implement Function{N} interfaces
 
 class B() : Function0<Boolean> {
     override fun invoke() = true

compiler/testData/diagnostics/testsWithJsStdLib/implementingFunction.kt

@@ -0,0 +1,9 @@
+abstract class <!IMPLEMENTING_FUNCTION_INTERFACE!>A<!> : () -> Unit
+
+<!IMPLEMENTING_FUNCTION_INTERFACE!>object B<!> : (String, Int) -> Long {
+    override fun invoke(a: String, B: Int) = 23L
+}
+
+abstract class <!IMPLEMENTING_FUNCTION_INTERFACE!>C<!> : kotlin.Function1<Any, Int>
+
+abstract class <!IMPLEMENTING_FUNCTION_INTERFACE!>D<!> : C()

compiler/testData/diagnostics/testsWithJsStdLib/implementingFunction.txt

@@ -0,0 +1,33 @@
+package
+
+public abstract class A : () -> kotlin.Unit {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun invoke(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public object B : (kotlin.String, kotlin.Int) -> kotlin.Long {
+    private constructor B()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ fun invoke(/*0*/ a: kotlin.String, /*1*/ B: kotlin.Int): kotlin.Long
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public abstract class C : (kotlin.Any) -> kotlin.Int {
+    public constructor C()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun invoke(/*0*/ p1: kotlin.Any): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public abstract class D : C {
+    public constructor D()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun invoke(/*0*/ p1: kotlin.Any): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java

@@ -36,6 +36,12 @@ public class DiagnosticsTestWithJsStdLibGenerated extends AbstractDiagnosticsTes
         KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/testsWithJsStdLib"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
     }
 
+    @TestMetadata("implementingFunction.kt")
+    public void testImplementingFunction() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/implementingFunction.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("localClassMetadata.kt")
     public void testLocalClassMetadata() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/localClassMetadata.kt");

core/builtins/src/kotlin/reflect/KProperty.kt

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+@file:Suppress("IMPLEMENTING_FUNCTION_INTERFACE")
 package kotlin.reflect
 
 /**

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/DefaultErrorMessagesJs.kt

@@ -71,6 +71,7 @@ private val DIAGNOSTIC_FACTORY_TO_RENDERER by lazy {
         put(ErrorsJs.OVERRIDING_EXTERNAL_FUN_WITH_OPTIONAL_PARAMS, "Overriding `external` function with optional parameters")
         put(ErrorsJs.OVERRIDING_EXTERNAL_FUN_WITH_OPTIONAL_PARAMS_WITH_FAKE,
             "Overriding `external` function with optional parameters by declaration from superclass: {0}", Renderers.COMPACT)
+        put(ErrorsJs.IMPLEMENTING_FUNCTION_INTERFACE, "Implementing function interface is prohibited in JavaScript")
 
         this
     }

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/ErrorsJs.java

@@ -20,6 +20,7 @@ import com.intellij.psi.PsiElement;
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor;
 import org.jetbrains.kotlin.diagnostics.*;
+import org.jetbrains.kotlin.psi.KtClassOrObject;
 import org.jetbrains.kotlin.psi.KtDeclaration;
 import org.jetbrains.kotlin.psi.KtElement;
 import org.jetbrains.kotlin.psi.KtExpression;
@@ -73,6 +74,8 @@ public interface ErrorsJs {
             DiagnosticFactory0.create(ERROR, PositioningStrategies.DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory1<KtElement, FunctionDescriptor> OVERRIDING_EXTERNAL_FUN_WITH_OPTIONAL_PARAMS_WITH_FAKE =
             DiagnosticFactory1.create(ERROR, PositioningStrategies.DECLARATION_SIGNATURE_OR_DEFAULT);
+    DiagnosticFactory0<KtClassOrObject> IMPLEMENTING_FUNCTION_INTERFACE = DiagnosticFactory0.create(
+            ERROR, PositioningStrategies.DECLARATION_SIGNATURE_OR_DEFAULT);
 
     @SuppressWarnings("UnusedDeclaration")
     Object _initializer = new Object() {

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsInheritanceChecker.kt

@@ -16,14 +16,20 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
-import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.builtins.isBuiltinFunctionalTypeOrSubtype
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
+import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.checkers.SimpleDeclarationChecker
 import org.jetbrains.kotlin.resolve.descriptorUtil.hasDefaultValue
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
+import org.jetbrains.kotlin.types.typeUtil.immediateSupertypes
 
 object JsInheritanceChecker : SimpleDeclarationChecker {
     override fun check(
@@ -44,6 +50,12 @@ object JsInheritanceChecker : SimpleDeclarationChecker {
                         declaration, fakeOverriddenMethod))
             }
         }
+
+        if (descriptor is ClassDescriptor &&
+            descriptor.defaultType.immediateSupertypes().any { it.isBuiltinFunctionalTypeOrSubtype }
+        ) {
+            diagnosticHolder.report(ErrorsJs.IMPLEMENTING_FUNCTION_INTERFACE.on(declaration as KtClassOrObject))
+        }
     }
 
     private fun isOverridingExternalWithOptionalParams(function: FunctionDescriptor): Boolean {

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

@@ -8870,7 +8870,13 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             @TestMetadata("kt3190.kt")
             public void testKt3190() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/invoke/kt3190.kt");
-                doTest(fileName);
+                try {
+                    doTest(fileName);
+                }
+                catch (Throwable ignore) {
+                    return;
+                }
+                throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
             }
 
             @TestMetadata("kt3297.kt")
@@ -8906,7 +8912,13 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             @TestMetadata("kt3822invokeOnThis.kt")
             public void testKt3822invokeOnThis() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/invoke/kt3822invokeOnThis.kt");
-                doTest(fileName);
+                try {
+                    doTest(fileName);
+                }
+                catch (Throwable ignore) {
+                    return;
+                }
+                throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
             }
         }