[JS] Allow customization of $isInstance for native types.

This allows `instanceof` on native interfaces if they define a custom `$isInstance` method. The custom `$isInstance` method cannot be private.

PiperOrigin-RevId: 561531763

jre/java/java/io/Serializable.java

@@ -17,15 +17,13 @@
 
 import javaemul.internal.ArrayHelper;
 import javaemul.internal.JsUtils;
-import jsinterop.annotations.JsMethod;
 
 /**
  * Provided for interoperability; RPC treats this interface synonymously with
  * {@link com.google.gwt.user.client.rpc.IsSerializable IsSerializable}.
  * The Java serialization protocol is explicitly not supported.
  */
 public interface Serializable {
-  @JsMethod
   static boolean $isInstance(HasSerializableTypeMarker instance) {
     if (instance == null) {
       return false;

jre/java/java/lang/Boolean.java

@@ -19,7 +19,6 @@
 import java.io.Serializable;
 import javaemul.internal.JsUtils;
 import javaemul.internal.Platform;
-import jsinterop.annotations.JsMethod;
 
 /**
  * Wraps native <code>boolean</code> as an object.
@@ -106,7 +105,6 @@ public String toString() {
     return toString(booleanValue());
   }
 
-  @JsMethod
   static boolean $isInstance(Object instance) {
     return "boolean".equals(JsUtils.typeOf(instance));
   }

jre/java/java/lang/CharSequence.java

@@ -23,7 +23,6 @@
 import java.util.stream.IntStream;
 import java.util.stream.StreamSupport;
 import javaemul.internal.JsUtils;
-import jsinterop.annotations.JsMethod;
 
 /**
  * Abstracts the notion of a sequence of characters.
@@ -58,7 +57,6 @@ public boolean hasNext() {
     }, Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.ORDERED, false);
   }
 
-  @JsMethod
   static boolean $isInstance(HasCharSequenceTypeMarker instance) {
     if (JsUtils.typeOf(instance).equals("string")) {
       return true;

jre/java/java/lang/Cloneable.java

@@ -16,14 +16,11 @@
 package java.lang;
 
 import javaemul.internal.ArrayHelper;
-import jsinterop.annotations.JsMethod;
 
 /**
  * Indicates that a class implements <code>clone()</code>.
  */
 public interface Cloneable {
-
-  @JsMethod
   static boolean $isInstance(HasCloneableTypeMarker instance) {
     if (instance == null) {
       return false;

jre/java/java/lang/Comparable.java

@@ -16,7 +16,6 @@
 package java.lang;
 
 import javaemul.internal.JsUtils;
-import jsinterop.annotations.JsMethod;
 
 /**
  * An interface used a basis for implementing custom ordering. <a
@@ -28,7 +27,6 @@
 public interface Comparable<T> {
   int compareTo(T other);
 
-  @JsMethod
   static boolean $isInstance(HasComparableTypeMarker instance) {
     String type = JsUtils.typeOf(instance);
     if (type.equals("boolean") || type.equals("number") || type.equals("string")) {

jre/java/java/lang/Double.java

@@ -18,7 +18,6 @@
 
 import javaemul.internal.JsUtils;
 import javaemul.internal.Platform;
-import jsinterop.annotations.JsMethod;
 
 /**
  * Wraps a primitive <code>double</code> as an object.
@@ -182,7 +181,6 @@ public String toString() {
     return toString(doubleValue());
   }
 
-  @JsMethod
   static boolean $isInstance(Object instance) {
     return "number".equals(JsUtils.typeOf(instance));
   }

jre/java/java/lang/Number.java

@@ -128,7 +128,6 @@ static class __ParseLong {
   @JsType(isNative = true, name = "Number$impl", namespace = "java.lang")
   private static class JavaLangNumber { }
 
-  @JsMethod
   static boolean $isInstance(Object instance) {
     return "number".equals(JsUtils.typeOf(instance)) || instance instanceof JavaLangNumber;
   }

jre/java/java/lang/Object.java

@@ -43,7 +43,6 @@ public final Class<?> getClass() {
     return Class.$get(Constructor.of(this));
   }
 
-  @JsMethod
   static boolean $isInstance(Object instance) {
     return instance != null;
   }

jre/java/java/lang/String.java

@@ -34,7 +34,6 @@
 import javaemul.internal.JsUtils;
 import javaemul.internal.NativeRegExp;
 import javaemul.internal.StringUtil;
-import jsinterop.annotations.JsMethod;
 import jsinterop.annotations.JsNonNull;
 import jsinterop.annotations.JsPackage;
 import jsinterop.annotations.JsProperty;
@@ -694,7 +693,6 @@ private static class NativeString {
     public native String toUpperCase();
   }
 
-  @JsMethod
   static boolean $isInstance(Object instance) {
     return "string".equals(JsUtils.typeOf(instance));
   }

tools/java/com/google/j2cl/tools/rta/RapidTypeAnalyser.java

@@ -114,6 +114,13 @@ private static void markTypeLive(Type type) {
     // When a type is marked as live, we need to explicitly mark the super interfaces as live since
     // we need markImplementor call (which are not tracked in AST).
     type.getSuperInterfaces().forEach(RapidTypeAnalyser::markTypeLive);
+
+    // Types are made live by `instanceof` and casts, so if the type has a custom $isInstance
+    // it should be also considered as if it was called.
+    Member isInstanceMember = type.getMemberByName("$isInstance");
+    if (isInstanceMember != null) {
+      onMemberReference(isInstanceMember);
+    }
   }
 
   private RapidTypeAnalyser() {}

transpiler/java/com/google/j2cl/transpiler/ast/MethodDescriptor.java

@@ -175,15 +175,15 @@ public boolean isSyntheticInstanceOfSupportMember() {
   }
 
   public static final String CONSTRUCTOR_METHOD_NAME = "<init>";
-  public static final String INIT_METHOD_NAME = "$init";
+  static final String INIT_METHOD_NAME = "$init";
   public static final String CTOR_METHOD_PREFIX = "$ctor";
   public static final String CLINIT_METHOD_NAME = "$clinit";
   public static final String VALUE_OF_METHOD_NAME = "valueOf"; // Boxed type valueOf() method.
-  public static final String IS_INSTANCE_METHOD_NAME = "$isInstance";
+  static final String IS_INSTANCE_METHOD_NAME = "$isInstance";
   public static final String MARK_IMPLEMENTOR_METHOD_NAME = "$markImplementor";
   public static final String CREATE_METHOD_NAME = "$create";
-  public static final String LOAD_MODULES_METHOD_NAME = "$loadModules";
-  public static final String COPY_METHOD_NAME = "$copy";
+  static final String LOAD_MODULES_METHOD_NAME = "$loadModules";
+  static final String COPY_METHOD_NAME = "$copy";
 
   public static String buildMethodSignature(
       String name, TypeDescriptor... parameterTypeDescriptors) {
@@ -683,7 +683,7 @@ public String getMangledName() {
         return getSimpleJsName();
       }
 
-      if (getOrigin().isSyntheticInstanceOfSupportMember()) {
+      if (getOrigin().isSyntheticInstanceOfSupportMember() || isCustomIsInstanceMethod()) {
         // Class support methods, like $isInstance and $markImplementor, should not be mangled.
         return getName();
       }

transpiler/java/com/google/j2cl/transpiler/passes/ImplementInstanceOfs.java

@@ -108,7 +108,7 @@ private static ExpressionStatement createMarkImplementorCall(
 
   /** Synthesizes the $isInstance method on the type. */
   private static void synthesizeIsInstanceMethod(Type type) {
-    if (type.containsMethod(MethodDescriptor.IS_INSTANCE_METHOD_NAME)) {
+    if (type.containsMethod(MethodDescriptor::isCustomIsInstanceMethod)) {
       // User provided an $isInstance method, skip generation.
       return;
     }

transpiler/java/com/google/j2cl/transpiler/passes/JsInteropRestrictionsChecker.java

@@ -909,7 +909,9 @@ private void checkTypeReferences(Type type) {
           @Override
           public void exitInstanceOfExpression(InstanceOfExpression instanceOfExpression) {
             TypeDescriptor testTypeDescriptor = instanceOfExpression.getTestTypeDescriptor();
-            if (testTypeDescriptor.isNative() && testTypeDescriptor.isInterface()) {
+            if (testTypeDescriptor.isNative()
+                && testTypeDescriptor.isInterface()
+                && !((DeclaredTypeDescriptor) testTypeDescriptor).hasCustomIsInstanceMethod()) {
               problems.error(
                   instanceOfExpression.getSourcePosition(),
                   "Cannot do instanceof against native JsType interface '%s'.",

transpiler/javatests/com/google/j2cl/integration/java/jsinteroptests/JsTypeTest.java

@@ -26,6 +26,7 @@
 import jsinterop.annotations.JsConstructor;
 import jsinterop.annotations.JsFunction;
 import jsinterop.annotations.JsMethod;
+import jsinterop.annotations.JsOverlay;
 import jsinterop.annotations.JsPackage;
 import jsinterop.annotations.JsProperty;
 import jsinterop.annotations.JsType;
@@ -47,6 +48,8 @@ public static void testAll() {
     testInstanceOf_jsoWithNativeButtonProto();
     testInstanceOf_jsoWithoutProto();
     testInstanceOf_jsoWithProto();
+    testInstanceOf_classWithCustomIsInstance();
+    testInstanceOf_interfaceWithCustomIsInstance();
     testInstanceOf_withNameSpace();
     testJsMethodWithDifferentVisiblities();
     testJsTypeField();
@@ -74,6 +77,38 @@ static class MyNativeJsTypeSubclass extends MyNativeJsType {
     public MyNativeJsTypeSubclass() {}
   }
 
+  @JsType(isNative = true, namespace = JsPackage.GLOBAL, name = "Array")
+  static class MyNativeClassWithCustomIsInstance {
+    @JsOverlay
+    static boolean $isInstance(Object o) {
+      return isCustomIsInstanceClassSingleton(o);
+    }
+  }
+
+  private static final String CUSTOM_IS_INSTANCE_CLASS_SINGLETON = "CustomIsInstanceClass";
+
+  // This method was extracted from $isInstance and ONLY called from there to ensure that
+  // rta traverses custom isInstance methods.
+  private static boolean isCustomIsInstanceClassSingleton(Object o) {
+    return o == CUSTOM_IS_INSTANCE_CLASS_SINGLETON;
+  }
+
+  @JsType(isNative = true, namespace = JsPackage.GLOBAL, name = "Array")
+  interface MyNativeInterfaceWithCustomIsInstance {
+    @JsOverlay
+    static boolean $isInstance(Object o) {
+      return isCustomIsInstanceInterfaceSingleton(o);
+    }
+  }
+
+  private static final String CUSTOM_IS_INSTANCE_INTERFACE_SINGLETON = "CustomIsInstanceInterface";
+
+  // This method was extracted from $isInstance and ONLY called from there to ensure that
+  // rta traverses custom isInstance methods.
+  private static boolean isCustomIsInstanceInterfaceSingleton(Object o) {
+    return o == CUSTOM_IS_INSTANCE_INTERFACE_SINGLETON;
+  }
+
   static class MyNativeJsTypeSubclassWithIterator extends MyNativeJsType implements Iterable {
     @JsConstructor
     public MyNativeJsTypeSubclassWithIterator() {}
@@ -262,6 +297,8 @@ private static void testInstanceOf_jsoWithProto() {
     assertFalse(object instanceof Iterator);
     assertTrue(object instanceof MyNativeJsType);
     assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
     assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
     assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
     assertTrue(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
@@ -280,6 +317,8 @@ private static void testInstanceOf_jsoWithoutProto() {
     assertFalse(object instanceof Iterator);
     assertFalse(object instanceof MyNativeJsType);
     assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
     assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
     assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
     assertFalse(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
@@ -298,6 +337,8 @@ private static void testInstanceOf_jsoWithNativeButtonProto() {
     assertFalse(object instanceof Iterator);
     assertFalse(object instanceof MyNativeJsType);
     assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
     assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
     assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
     assertFalse(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
@@ -317,6 +358,8 @@ private static void testInstanceOf_implementsJsType() {
     assertFalse(object instanceof Iterator);
     assertFalse(object instanceof MyNativeJsType);
     assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
     assertTrue(object instanceof ElementLikeNativeInterfaceImpl);
     assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
     assertFalse(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
@@ -336,6 +379,8 @@ private static void testInstanceOf_implementsJsTypeWithPrototype() {
     assertFalse(object instanceof Iterator);
     assertFalse(object instanceof MyNativeJsType);
     assertTrue(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
     assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
     assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
     assertFalse(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
@@ -355,6 +400,8 @@ private static void testInstanceOf_concreteJsType() {
     assertFalse(object instanceof Iterator);
     assertFalse(object instanceof MyNativeJsType);
     assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
     assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
     assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
     assertFalse(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
@@ -376,6 +423,8 @@ private static void testInstanceOf_extendsJsTypeWithProto() {
     assertFalse(object instanceof HTMLButtonElementConcreteNativeJsType);
     assertTrue(object instanceof Iterable);
     assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
     assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
     assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
     assertTrue(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
@@ -384,6 +433,48 @@ private static void testInstanceOf_extendsJsTypeWithProto() {
     assertFalse(object instanceof MyNativeJsTypeInterfaceImpl[][]);
   }
 
+  private static void testInstanceOf_classWithCustomIsInstance() {
+    Object object = CUSTOM_IS_INSTANCE_CLASS_SINGLETON;
+
+    assertTrue(object instanceof Object);
+    assertTrue(object instanceof String);
+    assertFalse(object instanceof HTMLElementConcreteNativeJsType);
+    assertFalse(object instanceof HTMLElementAnotherConcreteNativeJsType);
+    assertFalse(object instanceof HTMLButtonElementConcreteNativeJsType);
+    assertFalse(object instanceof Iterator);
+    assertFalse(object instanceof MyNativeJsType);
+    assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertTrue(object instanceof MyNativeClassWithCustomIsInstance);
+    assertFalse(object instanceof MyNativeInterfaceWithCustomIsInstance);
+    assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
+    assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
+    assertFalse(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
+    assertFalse(object instanceof ConcreteJsType);
+    assertFalse(object instanceof MyNativeJsTypeInterface[]);
+    assertFalse(object instanceof MyNativeJsTypeInterfaceImpl[][]);
+  }
+
+  private static void testInstanceOf_interfaceWithCustomIsInstance() {
+    Object object = CUSTOM_IS_INSTANCE_INTERFACE_SINGLETON;
+
+    assertTrue(object instanceof Object);
+    assertTrue(object instanceof String);
+    assertFalse(object instanceof HTMLElementConcreteNativeJsType);
+    assertFalse(object instanceof HTMLElementAnotherConcreteNativeJsType);
+    assertFalse(object instanceof HTMLButtonElementConcreteNativeJsType);
+    assertFalse(object instanceof Iterator);
+    assertFalse(object instanceof MyNativeJsType);
+    assertFalse(object instanceof MyNativeJsTypeInterfaceImpl);
+    assertFalse(object instanceof MyNativeClassWithCustomIsInstance);
+    assertTrue(object instanceof MyNativeInterfaceWithCustomIsInstance);
+    assertFalse(object instanceof ElementLikeNativeInterfaceImpl);
+    assertFalse(object instanceof MyJsInterfaceWithOnlyInstanceofReference);
+    assertFalse(object instanceof AliasToMyNativeJsTypeWithOnlyInstanceofReference);
+    assertFalse(object instanceof ConcreteJsType);
+    assertFalse(object instanceof MyNativeJsTypeInterface[]);
+    assertFalse(object instanceof MyNativeJsTypeInterfaceImpl[][]);
+  }
+
   private static void testInstanceOf_withNameSpace() {
     Object obj1 = createMyNamespacedJsInterface();
 

transpiler/javatests/com/google/j2cl/transpiler/JsInteropRestrictionsCheckerTest.java

@@ -3371,6 +3371,7 @@ public void testCustomIsInstanceSucceeds() {
             "    Object o = null;",
             "    boolean b = o instanceof InterfaceWithCustomIsInstance;",
             "    b = o instanceof ClassWithCustomIsInstance;",
+            "    b = o instanceof NativeInterfaceWithCustomIsInstance;",
             "    b = o instanceof NativeClassWithCustomIsInstance;",
             "  }",
             "}")