feat: add WARNING on usage top-level exportable declarations with non-consumable identifiers.

compiler/testData/diagnostics/testsWithJsStdLib/export/nonConsumableIdentifiers.kt

@@ -0,0 +1,42 @@
+// !OPT_IN: kotlin.js.ExperimentalJsExport
+// !RENDER_DIAGNOSTICS_MESSAGES
+
+package foo
+
+@JsExport
+fun <!NON_CONSUMABLE_EXPORTED_IDENTIFIER!>delete<!>() {}
+
+@JsExport
+val <!NON_CONSUMABLE_EXPORTED_IDENTIFIER!>instanceof<!> = 4
+
+@JsExport
+class <!NON_CONSUMABLE_EXPORTED_IDENTIFIER!>eval<!>
+
+@JsExport
+@JsName(<!NON_CONSUMABLE_EXPORTED_IDENTIFIER!>"await"<!>)
+fun foo() {}
+
+@JsExport
+@JsName(<!NON_CONSUMABLE_EXPORTED_IDENTIFIER!>"this"<!>)
+val bar = 4
+
+@JsExport
+@JsName(<!NON_CONSUMABLE_EXPORTED_IDENTIFIER!>"super"<!>)
+class Baz
+
+@JsExport
+class Test {
+    fun instanceof() {}
+
+    @JsName("eval")
+    fun test() {}
+}
+
+@JsExport
+object NaN
+
+@JsExport
+enum class Nums {
+    Infinity,
+    undefined
+}

compiler/testData/diagnostics/testsWithJsStdLib/export/nonConsumableIdentifiers.txt

@@ -0,0 +1,57 @@
+package
+
+package foo {
+    @kotlin.js.JsExport @kotlin.js.JsName(name = "this") public val bar: kotlin.Int = 4
+    @kotlin.js.JsExport public val instanceof: kotlin.Int = 4
+    @kotlin.js.JsExport public fun delete(): kotlin.Unit
+    @kotlin.js.JsExport @kotlin.js.JsName(name = "await") public fun foo(): kotlin.Unit
+
+    @kotlin.js.JsExport @kotlin.js.JsName(name = "super") public final class Baz {
+        public constructor Baz()
+        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*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    @kotlin.js.JsExport public object NaN {
+        private constructor NaN()
+        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*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    @kotlin.js.JsExport public final enum class Nums : kotlin.Enum<foo.Nums> {
+        enum entry Infinity
+
+        enum entry undefined
+
+        private constructor Nums()
+        public final override /*1*/ /*fake_override*/ val name: kotlin.String
+        public final override /*1*/ /*fake_override*/ val ordinal: kotlin.Int
+        protected final override /*1*/ /*fake_override*/ fun clone(): kotlin.Any
+        public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: foo.Nums): kotlin.Int
+        public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        // Static members
+        public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): foo.Nums
+        public final /*synthesized*/ fun values(): kotlin.Array<foo.Nums>
+    }
+
+    @kotlin.js.JsExport public final class Test {
+        public constructor Test()
+        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 final fun instanceof(): kotlin.Unit
+        @kotlin.js.JsName(name = "eval") public final fun test(): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    @kotlin.js.JsExport public final class eval {
+        public constructor eval()
+        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*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticsTestWithJsStdLibGenerated.java

@@ -401,6 +401,12 @@ public class DiagnosticsTestWithJsStdLibGenerated extends AbstractDiagnosticsTes
             runTest("compiler/testData/diagnostics/testsWithJsStdLib/export/jsExportOnNestedDeclarations.kt");
         }
 
+        @Test
+        @TestMetadata("nonConsumableIdentifiers.kt")
+        public void testNonConsumableIdentifiers() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithJsStdLib/export/nonConsumableIdentifiers.kt");
+        }
+
         @Test
         @TestMetadata("secondaryConstructorWithoutJsName.kt")
         public void testSecondaryConstructorWithoutJsName() throws Exception {

js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/jsScopes.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.js.backend.ast
 
+import org.jetbrains.kotlin.js.common.RESERVED_KEYWORDS
 import java.util.*
 
 class JsObjectScope(parent: JsScope, description: String) : JsScope(parent, description)
@@ -70,23 +71,7 @@ open class JsDeclarationScope(parent: JsScope, description: String, useParentSco
     }
 
     companion object {
-        val RESERVED_WORDS: Set<String> = setOf(
+        val RESERVED_WORDS: Set<String> = RESERVED_KEYWORDS + setOf(
-                // keywords
-                "await", "break", "case", "catch", "continue", "debugger", "default", "delete", "do", "else", "finally", "for", "function", "if",
-                "in", "instanceof", "new", "return", "switch", "this", "throw", "try", "typeof", "var", "void", "while", "with",
-
-                // future reserved words
-                "class", "const", "enum", "export", "extends", "import", "super",
-
-                // as future reserved words in strict mode
-                "implements", "interface", "let", "package", "private", "protected", "public", "static", "yield",
-
-                // additional reserved words
-                "null", "true", "false",
-
-                // disallowed as variable names in strict mode
-                "eval", "arguments",
-
                 // global identifiers usually declared in a typical JS interpreter
                 "NaN", "isNaN", "Infinity", "undefined",
                 "Error", "Object", "Math", "String", "Number", "Boolean", "Date", "Array", "RegExp", "JSON",

js/js.ast/src/org/jetbrains/kotlin/js/common/IdentifierPolicy.kt

@@ -49,4 +49,22 @@ fun String.isValidES5Identifier(): Boolean {
         if (!get(idx).isES5IdentifierPart()) return false
     }
     return true
-}
+}
+
+val RESERVED_KEYWORDS: Set<String> = setOf(
+    // keywords
+    "await", "break", "case", "catch", "continue", "debugger", "default", "delete", "do", "else", "finally", "for", "function", "if",
+    "in", "instanceof", "new", "return", "switch", "this", "throw", "try", "typeof", "var", "void", "while", "with",
+
+    // future reserved words
+    "class", "const", "enum", "export", "extends", "import", "super",
+
+    // as future reserved words in strict mode
+    "implements", "interface", "let", "package", "private", "protected", "public", "static", "yield",
+
+    // additional reserved words
+    "null", "true", "false",
+
+    // disallowed as variable names in strict mode
+    "eval", "arguments",
+)

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

@@ -106,6 +106,8 @@ private val DIAGNOSTIC_FACTORY_TO_RENDERER by lazy {
         put(ErrorsJs.WRONG_EXPORTED_DECLARATION, "Declaration of such kind ({0}) can''t be exported to JS", STRING)
         put(ErrorsJs.NON_EXPORTABLE_TYPE, "Exported declaration uses non-exportable {0} type: {1}", STRING, RENDER_TYPE)
 
+        put(ErrorsJs.NON_CONSUMABLE_EXPORTED_IDENTIFIER, "Exported declaration contains non-consumable identifier '${0}', that can't be represented inside TS definitions and ESM", STRING)
+
         this
     }
 }

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

@@ -110,6 +110,8 @@ public interface ErrorsJs {
     DiagnosticFactory1<KtExpression, String> WRONG_EXPORTED_DECLARATION = DiagnosticFactory1.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory2<PsiElement, String, KotlinType> NON_EXPORTABLE_TYPE = DiagnosticFactory2.create(WARNING, DECLARATION_SIGNATURE_OR_DEFAULT);
 
+    DiagnosticFactory1<PsiElement, String> NON_CONSUMABLE_EXPORTED_IDENTIFIER = DiagnosticFactory1.create(WARNING, DEFAULT);
+
     @SuppressWarnings("UnusedDeclaration")
     Object _initializer = new Object() {
         {

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

@@ -5,15 +5,19 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
+import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.builtins.isFunctionType
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.ClassKind.*
-import org.jetbrains.kotlin.js.resolve.diagnostics.JsExportDeclarationChecker.isExportable
+import org.jetbrains.kotlin.js.common.RESERVED_KEYWORDS
+import org.jetbrains.kotlin.js.naming.NameSuggestion
 import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
+import org.jetbrains.kotlin.psi.KtAnnotationEntry
 import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.psi.KtNamedDeclaration
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.BindingTrace
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.checkers.DeclarationChecker
 import org.jetbrains.kotlin.resolve.checkers.DeclarationCheckerContext
@@ -22,6 +26,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.isExtensionProperty
 import org.jetbrains.kotlin.resolve.descriptorUtil.isInsideInterface
 import org.jetbrains.kotlin.resolve.inline.isInlineWithReified
 import org.jetbrains.kotlin.resolve.isInlineClass
+import org.jetbrains.kotlin.resolve.source.getPsi
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.isDynamic
 import org.jetbrains.kotlin.types.typeUtil.*
@@ -61,6 +66,8 @@ object JsExportDeclarationChecker : DeclarationChecker {
             reportWrongExportedDeclaration("expect")
         }
 
+        validateDeclarationOnConsumableName(declaration, descriptor, trace)
+
         when (descriptor) {
             is FunctionDescriptor -> {
                 for (typeParameter in descriptor.typeParameters) {
@@ -201,4 +208,33 @@ object JsExportDeclarationChecker : DeclarationChecker {
 
         return descriptor.isEffectivelyExternal() || AnnotationsUtils.isExportedObject(descriptor, bindingContext)
     }
+
+    private fun validateDeclarationOnConsumableName(
+        declaration: KtDeclaration,
+        declarationDescriptor: DeclarationDescriptor,
+        trace: BindingTrace
+    ) {
+        if (!declarationDescriptor.isTopLevelInPackage() || declarationDescriptor.name.isSpecial) return
+
+        val name = declarationDescriptor.getKotlinOrJsName()
+
+        if (name !in RESERVED_KEYWORDS && NameSuggestion.sanitizeName(name) == name) return
+
+        val reportTarget = declarationDescriptor.getJsNameArgument() ?: declaration.getIdentifier()
+
+        trace.report(ErrorsJs.NON_CONSUMABLE_EXPORTED_IDENTIFIER.on(reportTarget, name))
+    }
+
+    private fun DeclarationDescriptor.getKotlinOrJsName(): String {
+        return AnnotationsUtils.getJsName(this) ?: name.identifier
+    }
+
+    private fun KtDeclaration.getIdentifier(): PsiElement {
+        return (this as KtNamedDeclaration).nameIdentifier!!
+    }
+
+    private fun DeclarationDescriptor.getJsNameArgument(): PsiElement? {
+        val jsNameAnnotation = AnnotationsUtils.getJsNameAnnotation(this) ?: return null
+        return (jsNameAnnotation.source.getPsi() as KtAnnotationEntry).valueArgumentList?.arguments?.first()
+    }
 }

js/js.frontend/src/org/jetbrains/kotlin/js/translate/utils/AnnotationsUtils.java

@@ -39,7 +39,7 @@ import java.util.List;
 import static org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt.isEffectivelyExternal;
 
 public final class AnnotationsUtils {
-    private static final String JS_NAME = "kotlin.js.JsName";
+    public static final FqName JS_NAME = new FqName("kotlin.js.JsName");
     private static final FqName JS_EXPORT = new FqName("kotlin.js.JsExport");
     public static final FqName JS_MODULE_ANNOTATION = new FqName("kotlin.js.JsModule");
     private static final FqName JS_NON_MODULE_ANNOTATION = new FqName("kotlin.js.JsNonModule");
@@ -172,7 +172,7 @@ public final class AnnotationsUtils {
 
     @Nullable
     public static AnnotationDescriptor getJsNameAnnotation(@NotNull DeclarationDescriptor descriptor) {
-        return descriptor.getAnnotations().findAnnotation(new FqName(JS_NAME));
+        return descriptor.getAnnotations().findAnnotation(JS_NAME);
     }
 
     @Nullable