KT-7397: use reference comparison (===) when translating a is A, where A is an object. Use more sophisticated check for reified parameters.

js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/metadata/metadataProperties.kt

@@ -62,7 +62,8 @@ enum class TypeCheck {
     INSTANCEOF,
     OR_NULL,
     IS_ANY,
-    AND_PREDICATE
+    AND_PREDICATE,
+    SAME_AS
 }
 
 enum class SideEffectKind {

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

@@ -59,6 +59,12 @@ public class RttiTestGenerated extends AbstractRttiTest {
         doTest(fileName);
     }
 
+    @TestMetadata("isReifiedObject.kt")
+    public void testIsReifiedObject() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/rtti/cases/isReifiedObject.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("isSameClass.kt")
     public void testIsSameClass() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/rtti/cases/isSameClass.kt");

js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java

@@ -400,6 +400,11 @@ public final class Namer {
         return invokeFunctionAndSetTypeCheckMetadata("isInstanceOf", type, TypeCheck.INSTANCEOF);
     }
 
+    @NotNull
+    public JsExpression isInstanceOfObject(@NotNull JsExpression type) {
+        return invokeFunctionAndSetTypeCheckMetadata("isInstanceOf", type, TypeCheck.SAME_AS);
+    }
+
     @NotNull
     public JsExpression orNull(@NotNull JsExpression callable) {
         return invokeFunctionAndSetTypeCheckMetadata("orNull", callable, TypeCheck.OR_NULL);

js/js.translator/src/org/jetbrains/kotlin/js/translate/expression/PatternTranslator.java

@@ -23,10 +23,7 @@ import org.jetbrains.kotlin.KtNodeTypes;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
 import org.jetbrains.kotlin.builtins.PrimitiveType;
 import org.jetbrains.kotlin.builtins.ReflectionTypes;
-import org.jetbrains.kotlin.descriptors.CallableDescriptor;
-import org.jetbrains.kotlin.descriptors.ClassDescriptor;
-import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
-import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor;
+import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.js.patterns.NamePredicate;
 import org.jetbrains.kotlin.js.patterns.typePredicates.TypePredicatesKt;
 import org.jetbrains.kotlin.js.translate.context.Namer;
@@ -170,8 +167,10 @@ public final class PatternTranslator extends AbstractTranslator {
             return result;
         }
 
-        JsNameRef typeName = getClassNameReference(type);
-        return namer().isInstanceOf(typeName);
+
+        ClassDescriptor referencedClass = DescriptorUtils.getClassDescriptorForType(type);
+        JsNameRef typeName = context().getQualifiedReference(referencedClass);
+        return referencedClass.getKind() != ClassKind.OBJECT ? namer().isInstanceOf(typeName) : namer().isInstanceOfObject(typeName);
     }
 
     @Nullable
@@ -235,12 +234,6 @@ public final class PatternTranslator extends AbstractTranslator {
         return alias;
     }
 
-    @NotNull
-    private JsNameRef getClassNameReference(@NotNull KotlinType type) {
-        ClassDescriptor referencedClass = DescriptorUtils.getClassDescriptorForType(type);
-        return context().getQualifiedReference(referencedClass);
-    }
-
     @NotNull
     public JsExpression translateExpressionPattern(
             @NotNull KotlinType type,

js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/expandIsCalls.kt

@@ -86,6 +86,12 @@ private class TypeCheckRewritingVisitor(private val context: TranslationContext)
                 if (calleeArguments.size == 1) context.namer().isInstanceOf(argument, calleeArguments[0]) else null
             }
 
+            TypeCheck.SAME_AS -> {
+                // `Kotlin.isInstanceOf(calleeArgument)(argument)` -> `argument === calleeArgument`
+                // when it's known at compile time that `argument` represents an object type
+                if (calleeArguments.size == 1) JsAstUtils.equality(argument, calleeArguments[0]) else null
+            }
+
             TypeCheck.OR_NULL -> {
                 // `Kotlin.orNull(calleeArgument)(argument)` -> `(tmp = argument) == null || calleeArgument(tmp)`
                 if (calleeArguments.size == 1) getReplacementForOrNull(argument, calleeArguments[0]) else null

js/js.translator/testData/kotlin_lib_ecma5.js

@@ -381,6 +381,15 @@
             return object instanceof klass;
         }
 
+        var proto = Object.getPrototypeOf(klass);
+        var constructor = proto != null ? proto.constructor : null;
+        if (constructor != null && "$metadata$" in constructor) {
+            var metadata = constructor.$metadata$;
+            if (metadata.type === Kotlin.TYPE.OBJECT) {
+                return object === klass;
+            }
+        }
+
         // In WebKit (JavaScriptCore) for some interfaces from DOM typeof returns "object", nevertheless they can be used in RHS of instanceof
         if (isNativeClass(klass)) {
             return object instanceof klass;

js/js.translator/testData/rtti/cases/isObject.kt

@@ -5,8 +5,7 @@ object Obj
 fun box(): String {
     val r: Any = Obj
 
-// TODO: fix KT-13465
-//    if (r !is Obj) return "r !is Obj"
+    if (r !is Obj) return "r !is Obj"
 
     return "OK"
 }

js/js.translator/testData/rtti/cases/isReifiedObject.kt

@@ -0,0 +1,13 @@
+// NO_INLINE
+package foo
+
+object Obj
+
+private inline fun <reified T> check(a: Any): String {
+    return if (a is T) "OK" else "fail"
+}
+
+fun box(): String {
+    var x: Any = Obj
+    return check<Obj>(x)
+}