V8 inheritance test illustration

cctest.diff

diff --git a/test/cctest/BUILD.gn b/test/cctest/BUILD.gn
index 1aa4a07ca4..9f0eaeeb3a 100644
--- a/test/cctest/BUILD.gn
+++ b/test/cctest/BUILD.gn
@@ -192,6 +192,7 @@ v8_source_set("cctest_sources") {
     "test-heap-profiler.cc",
     "test-identity-map.cc",
     "test-inobject-slack-tracking.cc",
+    "test-inheritance.cc",
     "test-intl.cc",
     "test-isolate-independent-builtins.cc",
     "test-liveedit.cc",
diff --git a/test/cctest/test-inheritance.cc b/test/cctest/test-inheritance.cc
new file mode 100644
index 0000000000..19c7115d31
--- /dev/null
+++ b/test/cctest/test-inheritance.cc
@@ -0,0 +1,66 @@
+#include "src/v8.h"
+#include "test/cctest/cctest.h"
+
+static const char js_script[] =
+"const x = function doSubclassCallTest(superClass) {"
+"  class Subclass extends superClass {};"
+"  const inst = new Subclass();"
+"  inst.superclassMethod();"
+"  return true;"
+"}; x";
+
+static const char js_script_proto[] =
+"const x = function doSubclassCallTest(superClass) {"
+"  const Subclass = function Subclass() {};"
+"  Object.setPrototypeOf(Subclass, superClass);"
+"  Object.setPrototypeOf(Subclass.prototype, superClass.prototype);"
+"  const inst = new Subclass();"
+"  inst.superclassMethod();"
+"  return true;"
+"}; x";
+
+namespace v8 {
+
+static void SuperclassConstructor(const FunctionCallbackInfo<Value> &info) {}
+static void SuperclassMethod(const FunctionCallbackInfo<Value> &info) {}
+
+namespace test_inheritance {
+
+static void do_test(const char* script) {
+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::isolate();
+  HandleScope scope(isolate);
+
+  auto context = isolate->GetCurrentContext();
+  auto tpl = FunctionTemplate::New(isolate, SuperclassConstructor);
+  auto name =
+      String::NewFromUtf8(isolate, "Superclass", NewStringType::kNormal)
+          .ToLocalChecked();
+  tpl->SetClassName(name);
+  auto method_tpl = FunctionTemplate::New(isolate, SuperclassMethod,
+      Local<Value>(), Signature::New(isolate, tpl));
+  tpl->PrototypeTemplate()->Set(isolate, "superclassMethod", method_tpl);
+
+  auto script_source =
+      String::NewFromUtf8(isolate, script, NewStringType::kNormal)
+          .ToLocalChecked();
+
+  auto test_script = Script::Compile(context, script_source).ToLocalChecked();
+  auto test_function = test_script->Run(context).ToLocalChecked();
+  auto function_to_pass = tpl->GetFunction().As<Value>();
+  auto result = test_function.As<Function>()->Call(context,
+      Undefined(isolate).As<Value>(), 1, &function_to_pass);
+  CHECK(!result.IsEmpty());
+  CHECK(result.ToLocalChecked().As<Boolean>()->Value());
+}
+
+TEST(Inheritance) {
+  do_test(js_script);
+}
+
+TEST(ProtoInheritance) {
+  do_test(js_script_proto);
+}
+
+}  // namespace test_inheritance
+}  // namespace v8