[api] Expose instanceof through v8::Value::InstanceOf.

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 99f021d7acc3c2ad85c2ccc753822fb107849f8d..02d1dd58661da485641d03590497ed333f49e9eb 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -6224,6 +6224,63 @@ THREADED_TEST(TypeOf) {
             .FromJust());
 }
 
+THREADED_TEST(InstanceOf) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  CompileRun(
+      "var A = {};"
+      "var B = {};"
+      "var C = {};"
+      "B.__proto__ = A;"
+      "C.__proto__ = B;"
+      "function F() {}"
+      "F.prototype = A;"
+      "var G = { [Symbol.hasInstance] : null};"
+      "var H = { [Symbol.hasInstance] : () => { throw new Error(); } };"
+      "var J = { [Symbol.hasInstance] : () => true };"
+      "class K {}"
+      "var D = new K;"
+      "class L extends K {}"
+      "var E = new L");
+
+  v8::Local<v8::Object> f = v8::Local<v8::Object>::Cast(CompileRun("F"));
+  v8::Local<v8::Object> g = v8::Local<v8::Object>::Cast(CompileRun("G"));
+  v8::Local<v8::Object> h = v8::Local<v8::Object>::Cast(CompileRun("H"));
+  v8::Local<v8::Object> j = v8::Local<v8::Object>::Cast(CompileRun("J"));
+  v8::Local<v8::Object> k = v8::Local<v8::Object>::Cast(CompileRun("K"));
+  v8::Local<v8::Object> l = v8::Local<v8::Object>::Cast(CompileRun("L"));
+  v8::Local<v8::Value> a = v8::Local<v8::Value>::Cast(CompileRun("A"));
+  v8::Local<v8::Value> b = v8::Local<v8::Value>::Cast(CompileRun("B"));
+  v8::Local<v8::Value> c = v8::Local<v8::Value>::Cast(CompileRun("C"));
+  v8::Local<v8::Value> d = v8::Local<v8::Value>::Cast(CompileRun("D"));
+  v8::Local<v8::Value> e = v8::Local<v8::Value>::Cast(CompileRun("E"));
+
+  v8::TryCatch try_catch(env->GetIsolate());
+  CHECK(!a->InstanceOf(env.local(), f).ToChecked());
+  CHECK(b->InstanceOf(env.local(), f).ToChecked());
+  CHECK(c->InstanceOf(env.local(), f).ToChecked());
+  CHECK(!d->InstanceOf(env.local(), f).ToChecked());
+  CHECK(!e->InstanceOf(env.local(), f).ToChecked());
+  CHECK(!try_catch.HasCaught());
+
+  CHECK(a->InstanceOf(env.local(), g).IsNothing());
+  CHECK(try_catch.HasCaught());
+  try_catch.Reset();
+
+  CHECK(b->InstanceOf(env.local(), h).IsNothing());
+  CHECK(try_catch.HasCaught());
+  try_catch.Reset();
+
+  CHECK(v8_num(1)->InstanceOf(env.local(), j).ToChecked());
+  CHECK(!try_catch.HasCaught());
+
+  CHECK(d->InstanceOf(env.local(), k).ToChecked());
+  CHECK(e->InstanceOf(env.local(), k).ToChecked());
+  CHECK(!d->InstanceOf(env.local(), l).ToChecked());
+  CHECK(e->InstanceOf(env.local(), l).ToChecked());
+  CHECK(!try_catch.HasCaught());
+}
+
 THREADED_TEST(MultiRun) {
   LocalContext context;
   v8::HandleScope scope(context->GetIsolate());