unittests/VMRuntime/AdditionalSlots.h

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#ifndef HERMES_UNITTESTS_VMRUNTIME_ADDITIONALSLOTSTEST_H
#define HERMES_UNITTESTS_VMRUNTIME_ADDITIONALSLOTSTEST_H

#include "gtest/gtest.h"
#include "hermes/VM/JSObject.h"
#include "hermes/VM/PrimitiveBox.h"

namespace hermes {
namespace vm {

template <typename T>
size_t numAdditionalSlotsForTest() {
  // Allocate the maximum possible number of anonymous property slots, this
  // ensures that we use both direct and indirect storage.
  static_assert(
      InternalProperty::NumAnonymousInternalProperties >
          JSObject::DIRECT_PROPERTY_SLOTS,
      "Must use both direct and indirect prop storage.");
  constexpr size_t numAdditionalSlots =
      InternalProperty::NumAnonymousInternalProperties -
      JSObject::numOverlapSlots<T>();
  static_assert(
      numAdditionalSlots > 1, "At least 2 properties needed for this test");
  return numAdditionalSlots;
}

template <typename T>
void testAdditionalSlots(Runtime &runtime, Handle<T> handle) {
  size_t numAdditionalSlots = numAdditionalSlotsForTest<T>();
  PseudoHandle<JSNumber> boxedNum = JSNumber::create(
      runtime, 3.14, Handle<JSObject>::vmcast(&runtime.numberPrototype));
  T::setAdditionalSlotValue(
      *handle,
      runtime,
      0,
      SmallHermesValue::encodeObjectValue(boxedNum.get(), runtime));

  for (size_t i = 1; i < numAdditionalSlots; i++) {
    const auto shv = SmallHermesValue::encodeNumberValue(i, runtime);
    T::setAdditionalSlotValue(*handle, runtime, i, shv);
  }

  // Verify slot values survive GC.
  runtime.collect("test");
  JSNumber *n = vmcast<JSNumber>(
      T::getAdditionalSlotValue(*handle, runtime, 0).getObject(runtime));
  EXPECT_EQ(n->getPrimitiveNumber(), 3.14);

  for (size_t i = 1; i < numAdditionalSlots; i++)
    EXPECT_EQ(
        T::getAdditionalSlotValue(*handle, runtime, i).getNumber(runtime), i);
}

} // namespace vm
} // namespace hermes

#endif // HERMES_UNITTESTS_VMRUNTIME_ADDITIONALSLOTSTEST_H