2020/04/03, 02:34, v1.2.0

1 files changed, 3649 insertions, 0 deletions

diff --git a/node_modules/node-addon-api/src/node_api.cc b/node_modules/node-addon-api/src/node_api.cc
new file mode 100644
index 0000000..dd16016
--- /dev/null
+++ b/node_modules/node-addon-api/src/node_api.cc
@@ -0,0 +1,3649 @@
+/******************************************************************************
+ * Experimental prototype for demonstrating VM agnostic and ABI stable API
+ * for native modules to use instead of using Nan and V8 APIs directly.
+ *
+ * The current status is "Experimental" and should not be used for
+ * production applications.  The API is still subject to change
+ * and as an experimental feature is NOT subject to semver.
+ *
+ ******************************************************************************/
+
+#include <node_buffer.h>
+#include <node_object_wrap.h>
+#include <limits.h>  // INT_MAX
+#include <string.h>
+#include <algorithm>
+#include <cmath>
+#include <vector>
+#include "node_api.h"
+#include "node_internals.h"
+
+#define NAPI_VERSION  1
+
+static
+napi_status napi_set_last_error(napi_env env, napi_status error_code,
+                                uint32_t engine_error_code = 0,
+                                void* engine_reserved = nullptr);
+static
+napi_status napi_clear_last_error(napi_env env);
+
+struct napi_env__ {
+  explicit napi_env__(v8::Isolate* _isolate): isolate(_isolate),
+      has_instance_available(true), last_error() {}
+  ~napi_env__() {
+    last_exception.Reset();
+    has_instance.Reset();
+    wrap_template.Reset();
+  }
+  v8::Isolate* isolate;
+  v8::Persistent<v8::Value> last_exception;
+  v8::Persistent<v8::Value> has_instance;
+  v8::Persistent<v8::ObjectTemplate> wrap_template;
+  bool has_instance_available;
+  napi_extended_error_info last_error;
+  int open_handle_scopes = 0;
+};
+
+#define ENV_OBJECT_TEMPLATE(env, prefix, destination, field_count) \
+  do {                                                             \
+    if ((env)->prefix ## _template.IsEmpty()) {                    \
+      (destination) = v8::ObjectTemplate::New(isolate);            \
+      (destination)->SetInternalFieldCount((field_count));         \
+      (env)->prefix ## _template.Reset(isolate, (destination));    \
+    } else {                                                       \
+      (destination) = v8::Local<v8::ObjectTemplate>::New(          \
+          isolate, env->prefix ## _template);                      \
+    }                                                              \
+  } while (0)
+
+#define RETURN_STATUS_IF_FALSE(env, condition, status)                  \
+  do {                                                                  \
+    if (!(condition)) {                                                 \
+      return napi_set_last_error((env), (status));                      \
+    }                                                                   \
+  } while (0)
+
+#define CHECK_ENV(env)        \
+  if ((env) == nullptr) {     \
+    return napi_invalid_arg;  \
+  }
+
+#define CHECK_ARG(env, arg) \
+  RETURN_STATUS_IF_FALSE((env), ((arg) != nullptr), napi_invalid_arg)
+
+#define CHECK_MAYBE_EMPTY(env, maybe, status) \
+  RETURN_STATUS_IF_FALSE((env), !((maybe).IsEmpty()), (status))
+
+#define CHECK_MAYBE_NOTHING(env, maybe, status) \
+  RETURN_STATUS_IF_FALSE((env), !((maybe).IsNothing()), (status))
+
+// NAPI_PREAMBLE is not wrapped in do..while: try_catch must have function scope
+#define NAPI_PREAMBLE(env)                                       \
+  CHECK_ENV((env));                                              \
+  RETURN_STATUS_IF_FALSE((env), (env)->last_exception.IsEmpty(), \
+                         napi_pending_exception);                \
+  napi_clear_last_error((env));                                  \
+  v8impl::TryCatch try_catch((env))
+
+#define CHECK_TO_TYPE(env, type, context, result, src, status)                \
+  do {                                                                        \
+    CHECK_ARG((env), (src));                                                  \
+    auto maybe = v8impl::V8LocalValueFromJsValue((src))->To##type((context)); \
+    CHECK_MAYBE_EMPTY((env), maybe, (status));                                \
+    (result) = maybe.ToLocalChecked();                                        \
+  } while (0)
+
+#define CHECK_TO_FUNCTION(env, result, src)                                 \
+  do {                                                                      \
+    CHECK_ARG((env), (src));                                                \
+    v8::Local<v8::Value> v8value = v8impl::V8LocalValueFromJsValue((src));  \
+    RETURN_STATUS_IF_FALSE((env), v8value->IsFunction(), napi_invalid_arg); \
+    (result) = v8value.As<v8::Function>();                                  \
+  } while (0)
+
+#define CHECK_TO_OBJECT(env, context, result, src) \
+  CHECK_TO_TYPE((env), Object, (context), (result), (src), napi_object_expected)
+
+#define CHECK_TO_STRING(env, context, result, src) \
+  CHECK_TO_TYPE((env), String, (context), (result), (src), napi_string_expected)
+
+#define CHECK_TO_NUMBER(env, context, result, src) \
+  CHECK_TO_TYPE((env), Number, (context), (result), (src), napi_number_expected)
+
+#define CHECK_TO_BOOL(env, context, result, src)            \
+  CHECK_TO_TYPE((env), Boolean, (context), (result), (src), \
+    napi_boolean_expected)
+
+// n-api defines NAPI_AUTO_LENGHTH as the indicator that a string
+// is null terminated. For V8 the equivalent is -1. The assert
+// validates that our cast of NAPI_AUTO_LENGTH results in -1 as
+// needed by V8.
+#define CHECK_NEW_FROM_UTF8_LEN(env, result, str, len)                   \
+  do {                                                                   \
+    static_assert(static_cast<int>(NAPI_AUTO_LENGTH) == -1,              \
+                  "Casting NAPI_AUTO_LENGTH to int must result in -1");  \
+    RETURN_STATUS_IF_FALSE((env),                                        \
+        (len == NAPI_AUTO_LENGTH) || len <= INT_MAX,                     \
+        napi_invalid_arg);                                               \
+    auto str_maybe = v8::String::NewFromUtf8(                            \
+        (env)->isolate, (str), v8::NewStringType::kInternalized,         \
+        static_cast<int>(len));                                          \
+    CHECK_MAYBE_EMPTY((env), str_maybe, napi_generic_failure);           \
+    (result) = str_maybe.ToLocalChecked();                               \
+  } while (0)
+
+#define CHECK_NEW_FROM_UTF8(env, result, str) \
+  CHECK_NEW_FROM_UTF8_LEN((env), (result), (str), NAPI_AUTO_LENGTH)
+
+#define GET_RETURN_STATUS(env)      \
+  (!try_catch.HasCaught() ? napi_ok \
+                         : napi_set_last_error((env), napi_pending_exception))
+
+#define THROW_RANGE_ERROR_IF_FALSE(env, condition, error, message) \
+  do {                                                             \
+    if (!(condition)) {                                            \
+      napi_throw_range_error((env), (error), (message));           \
+      return napi_set_last_error((env), napi_generic_failure);     \
+    }                                                              \
+  } while (0)
+
+#define CREATE_TYPED_ARRAY(                                                    \
+    env, type, size_of_element, buffer, byte_offset, length, out)              \
+  do {                                                                         \
+    if ((size_of_element) > 1) {                                               \
+      THROW_RANGE_ERROR_IF_FALSE(                                              \
+          (env), (byte_offset) % (size_of_element) == 0,                       \
+          "ERR_NAPI_INVALID_TYPEDARRAY_ALIGNMENT",                             \
+          "start offset of "#type" should be a multiple of "#size_of_element); \
+    }                                                                          \
+    THROW_RANGE_ERROR_IF_FALSE((env), (length) * (size_of_element) +           \
+        (byte_offset) <= buffer->ByteLength(),                                 \
+        "ERR_NAPI_INVALID_TYPEDARRAY_LENGTH",                                  \
+        "Invalid typed array length");                                         \
+    (out) = v8::type::New((buffer), (byte_offset), (length));                  \
+  } while (0)
+
+#define NAPI_CALL_INTO_MODULE(env, call, handle_exception)                   \
+  do {                                                                       \
+    int open_handle_scopes = (env)->open_handle_scopes;                      \
+    napi_clear_last_error((env));                                            \
+    call;                                                                    \
+    CHECK_EQ((env)->open_handle_scopes, open_handle_scopes);                 \
+    if (!(env)->last_exception.IsEmpty()) {                                  \
+      handle_exception(                                                      \
+          v8::Local<v8::Value>::New((env)->isolate, (env)->last_exception)); \
+      (env)->last_exception.Reset();                                         \
+    }                                                                        \
+  } while (0)
+
+#define NAPI_CALL_INTO_MODULE_THROW(env, call) \
+  NAPI_CALL_INTO_MODULE((env), call, (env)->isolate->ThrowException)
+
+namespace {
+namespace v8impl {
+
+// convert from n-api property attributes to v8::PropertyAttribute
+static inline v8::PropertyAttribute V8PropertyAttributesFromDescriptor(
+    const napi_property_descriptor* descriptor) {
+  unsigned int attribute_flags = v8::PropertyAttribute::None;
+
+  if (descriptor->getter != nullptr || descriptor->setter != nullptr) {
+    // The napi_writable attribute is ignored for accessor descriptors, but
+    // V8 requires the ReadOnly attribute to match nonexistence of a setter.
+    attribute_flags |= (descriptor->setter == nullptr ?
+      v8::PropertyAttribute::ReadOnly : v8::PropertyAttribute::None);
+  } else if ((descriptor->attributes & napi_writable) == 0) {
+    attribute_flags |= v8::PropertyAttribute::ReadOnly;
+  }
+
+  if ((descriptor->attributes & napi_enumerable) == 0) {
+    attribute_flags |= v8::PropertyAttribute::DontEnum;
+  }
+  if ((descriptor->attributes & napi_configurable) == 0) {
+    attribute_flags |= v8::PropertyAttribute::DontDelete;
+  }
+
+  return static_cast<v8::PropertyAttribute>(attribute_flags);
+}
+
+class HandleScopeWrapper {
+ public:
+  explicit HandleScopeWrapper(v8::Isolate* isolate) : scope(isolate) {}
+
+ private:
+  v8::HandleScope scope;
+};
+
+// In node v0.10 version of v8, there is no EscapableHandleScope and the
+// node v0.10 port use HandleScope::Close(Local<T> v) to mimic the behavior
+// of a EscapableHandleScope::Escape(Local<T> v), but it is not the same
+// semantics. This is an example of where the api abstraction fail to work
+// across different versions.
+class EscapableHandleScopeWrapper {
+ public:
+  explicit EscapableHandleScopeWrapper(v8::Isolate* isolate)
+      : scope(isolate), escape_called_(false) {}
+  bool escape_called() const {
+    return escape_called_;
+  }
+  template <typename T>
+  v8::Local<T> Escape(v8::Local<T> handle) {
+    escape_called_ = true;
+    return scope.Escape(handle);
+  }
+
+ private:
+  v8::EscapableHandleScope scope;
+  bool escape_called_;
+};
+
+static
+napi_handle_scope JsHandleScopeFromV8HandleScope(HandleScopeWrapper* s) {
+  return reinterpret_cast<napi_handle_scope>(s);
+}
+
+static
+HandleScopeWrapper* V8HandleScopeFromJsHandleScope(napi_handle_scope s) {
+  return reinterpret_cast<HandleScopeWrapper*>(s);
+}
+
+static
+napi_escapable_handle_scope JsEscapableHandleScopeFromV8EscapableHandleScope(
+    EscapableHandleScopeWrapper* s) {
+  return reinterpret_cast<napi_escapable_handle_scope>(s);
+}
+
+static
+EscapableHandleScopeWrapper*
+V8EscapableHandleScopeFromJsEscapableHandleScope(
+    napi_escapable_handle_scope s) {
+  return reinterpret_cast<EscapableHandleScopeWrapper*>(s);
+}
+
+//=== Conversion between V8 Handles and napi_value ========================
+
+// This asserts v8::Local<> will always be implemented with a single
+// pointer field so that we can pass it around as a void*.
+static_assert(sizeof(v8::Local<v8::Value>) == sizeof(napi_value),
+  "Cannot convert between v8::Local<v8::Value> and napi_value");
+
+static
+napi_deferred JsDeferredFromV8Persistent(v8::Persistent<v8::Value>* local) {
+  return reinterpret_cast<napi_deferred>(local);
+}
+
+static
+v8::Persistent<v8::Value>* V8PersistentFromJsDeferred(napi_deferred local) {
+  return reinterpret_cast<v8::Persistent<v8::Value>*>(local);
+}
+
+static
+napi_value JsValueFromV8LocalValue(v8::Local<v8::Value> local) {
+  return reinterpret_cast<napi_value>(*local);
+}
+
+static
+v8::Local<v8::Value> V8LocalValueFromJsValue(napi_value v) {
+  v8::Local<v8::Value> local;
+  memcpy(&local, &v, sizeof(v));
+  return local;
+}
+
+static inline void trigger_fatal_exception(
+    napi_env env, v8::Local<v8::Value> local_err) {
+  v8::TryCatch try_catch(env->isolate);
+  env->isolate->ThrowException(local_err);
+  node::FatalException(env->isolate, try_catch);
+}
+
+static inline napi_status V8NameFromPropertyDescriptor(napi_env env,
+                                         const napi_property_descriptor* p,
+                                         v8::Local<v8::Name>* result) {
+  if (p->utf8name != nullptr) {
+    CHECK_NEW_FROM_UTF8(env, *result, p->utf8name);
+  } else {
+    v8::Local<v8::Value> property_value =
+      v8impl::V8LocalValueFromJsValue(p->name);
+
+    RETURN_STATUS_IF_FALSE(env, property_value->IsName(), napi_name_expected);
+    *result = property_value.As<v8::Name>();
+  }
+
+  return napi_ok;
+}
+
+// Adapter for napi_finalize callbacks.
+class Finalizer {
+ protected:
+  Finalizer(napi_env env,
+             napi_finalize finalize_callback,
+             void* finalize_data,
+             void* finalize_hint)
+    : _env(env),
+      _finalize_callback(finalize_callback),
+      _finalize_data(finalize_data),
+      _finalize_hint(finalize_hint) {
+  }
+
+  ~Finalizer() {
+  }
+
+ public:
+  static Finalizer* New(napi_env env,
+                        napi_finalize finalize_callback = nullptr,
+                        void* finalize_data = nullptr,
+                        void* finalize_hint = nullptr) {
+    return new Finalizer(
+      env, finalize_callback, finalize_data, finalize_hint);
+  }
+
+  static void Delete(Finalizer* finalizer) {
+    delete finalizer;
+  }
+
+  // node::Buffer::FreeCallback
+  static void FinalizeBufferCallback(char* data, void* hint) {
+    Finalizer* finalizer = static_cast<Finalizer*>(hint);
+    if (finalizer->_finalize_callback != nullptr) {
+      NAPI_CALL_INTO_MODULE_THROW(finalizer->_env,
+        finalizer->_finalize_callback(
+          finalizer->_env,
+          data,
+          finalizer->_finalize_hint));
+    }
+
+    Delete(finalizer);
+  }
+
+ protected:
+  napi_env _env;
+  napi_finalize _finalize_callback;
+  void* _finalize_data;
+  void* _finalize_hint;
+};
+
+// Wrapper around v8::Persistent that implements reference counting.
+class Reference : private Finalizer {
+ private:
+  Reference(napi_env env,
+            v8::Local<v8::Value> value,
+            uint32_t initial_refcount,
+            bool delete_self,
+            napi_finalize finalize_callback,
+            void* finalize_data,
+            void* finalize_hint)
+       : Finalizer(env, finalize_callback, finalize_data, finalize_hint),
+        _persistent(env->isolate, value),
+        _refcount(initial_refcount),
+        _delete_self(delete_self) {
+    if (initial_refcount == 0) {
+      _persistent.SetWeak(
+          this, FinalizeCallback, v8::WeakCallbackType::kParameter);
+      _persistent.MarkIndependent();
+    }
+  }
+
+  ~Reference() {
+    // The V8 Persistent class currently does not reset in its destructor:
+    // see NonCopyablePersistentTraits::kResetInDestructor = false.
+    // (Comments there claim that might change in the future.)
+    // To avoid memory leaks, it is better to reset at this time, however
+    // care must be taken to avoid attempting this after the Isolate has
+    // shut down, for example via a static (atexit) destructor.
+    _persistent.Reset();
+  }
+
+ public:
+  static Reference* New(napi_env env,
+                        v8::Local<v8::Value> value,
+                        uint32_t initial_refcount,
+                        bool delete_self,
+                        napi_finalize finalize_callback = nullptr,
+                        void* finalize_data = nullptr,
+                        void* finalize_hint = nullptr) {
+    return new Reference(env,
+      value,
+      initial_refcount,
+      delete_self,
+      finalize_callback,
+      finalize_data,
+      finalize_hint);
+  }
+
+  static void Delete(Reference* reference) {
+    delete reference;
+  }
+
+  uint32_t Ref() {
+    if (++_refcount == 1) {
+      _persistent.ClearWeak();
+    }
+
+    return _refcount;
+  }
+
+  uint32_t Unref() {
+    if (_refcount == 0) {
+        return 0;
+    }
+    if (--_refcount == 0) {
+      _persistent.SetWeak(
+          this, FinalizeCallback, v8::WeakCallbackType::kParameter);
+      _persistent.MarkIndependent();
+    }
+
+    return _refcount;
+  }
+
+  uint32_t RefCount() {
+    return _refcount;
+  }
+
+  v8::Local<v8::Value> Get() {
+    if (_persistent.IsEmpty()) {
+      return v8::Local<v8::Value>();
+    } else {
+      return v8::Local<v8::Value>::New(_env->isolate, _persistent);
+    }
+  }
+
+ private:
+  static void FinalizeCallback(const v8::WeakCallbackInfo<Reference>& data) {
+    Reference* reference = data.GetParameter();
+    reference->_persistent.Reset();
+
+    // Check before calling the finalize callback, because the callback might
+    // delete it.
+    bool delete_self = reference->_delete_self;
+    napi_env env = reference->_env;
+
+    if (reference->_finalize_callback != nullptr) {
+      NAPI_CALL_INTO_MODULE_THROW(env,
+        reference->_finalize_callback(
+            reference->_env,
+            reference->_finalize_data,
+            reference->_finalize_hint));
+    }
+
+    if (delete_self) {
+      Delete(reference);
+    }
+  }
+
+  v8::Persistent<v8::Value> _persistent;
+  uint32_t _refcount;
+  bool _delete_self;
+};
+
+class TryCatch : public v8::TryCatch {
+ public:
+  explicit TryCatch(napi_env env)
+      : v8::TryCatch(env->isolate), _env(env) {}
+
+  ~TryCatch() {
+    if (HasCaught()) {
+      _env->last_exception.Reset(_env->isolate, Exception());
+    }
+  }
+
+ private:
+  napi_env _env;
+};
+
+//=== Function napi_callback wrapper =================================
+
+// Use this data structure to associate callback data with each N-API function
+// exposed to JavaScript. The structure is stored in a v8::External which gets
+// passed into our callback wrapper. This reduces the performance impact of
+// calling through N-API.
+// Ref: benchmark/misc/function_call
+// Discussion (incl. perf. data): https://github.com/nodejs/node/pull/21072
+struct CallbackBundle {
+  // Bind the lifecycle of `this` C++ object to a JavaScript object.
+  // We never delete a CallbackBundle C++ object directly.
+  void BindLifecycleTo(v8::Isolate* isolate, v8::Local<v8::Value> target) {
+    handle.Reset(isolate, target);
+    handle.SetWeak(this, WeakCallback, v8::WeakCallbackType::kParameter);
+  }
+
+  napi_env       env;      // Necessary to invoke C++ NAPI callback
+  void*          cb_data;  // The user provided callback data
+  napi_callback  function_or_getter;
+  napi_callback  setter;
+  node::Persistent<v8::Value> handle;  // Die with this JavaScript object
+
+ private:
+  static void WeakCallback(v8::WeakCallbackInfo<CallbackBundle> const& info) {
+    // Use the "WeakCallback mechanism" to delete the C++ `bundle` object.
+    // This will be called when the v8::External containing `this` pointer
+    // is being GC-ed.
+    CallbackBundle* bundle = info.GetParameter();
+    if (bundle != nullptr) {
+      delete bundle;
+    }
+  }
+};
+
+// Base class extended by classes that wrap V8 function and property callback
+// info.
+class CallbackWrapper {
+ public:
+  CallbackWrapper(napi_value this_arg, size_t args_length, void* data)
+      : _this(this_arg), _args_length(args_length), _data(data) {}
+
+  virtual napi_value GetNewTarget() = 0;
+  virtual void Args(napi_value* buffer, size_t bufferlength) = 0;
+  virtual void SetReturnValue(napi_value value) = 0;
+
+  napi_value This() { return _this; }
+
+  size_t ArgsLength() { return _args_length; }
+
+  void* Data() { return _data; }
+
+ protected:
+  const napi_value _this;
+  const size_t _args_length;
+  void* _data;
+};
+
+template <typename Info, napi_callback CallbackBundle::*FunctionField>
+class CallbackWrapperBase : public CallbackWrapper {
+ public:
+  CallbackWrapperBase(const Info& cbinfo, const size_t args_length)
+      : CallbackWrapper(JsValueFromV8LocalValue(cbinfo.This()),
+                        args_length,
+                        nullptr),
+        _cbinfo(cbinfo) {
+    _bundle = reinterpret_cast<CallbackBundle*>(
+        v8::Local<v8::External>::Cast(cbinfo.Data())->Value());
+    _data = _bundle->cb_data;
+  }
+
+  napi_value GetNewTarget() override { return nullptr; }
+
+ protected:
+  void InvokeCallback() {
+    napi_callback_info cbinfo_wrapper = reinterpret_cast<napi_callback_info>(
+        static_cast<CallbackWrapper*>(this));
+
+    // All other pointers we need are stored in `_bundle`
+    napi_env env = _bundle->env;
+    napi_callback cb = _bundle->*FunctionField;
+
+    napi_value result;
+    NAPI_CALL_INTO_MODULE_THROW(env, result = cb(env, cbinfo_wrapper));
+
+    if (result != nullptr) {
+      this->SetReturnValue(result);
+    }
+  }
+
+  const Info& _cbinfo;
+  CallbackBundle* _bundle;
+};
+
+class FunctionCallbackWrapper
+    : public CallbackWrapperBase<v8::FunctionCallbackInfo<v8::Value>,
+                                 &CallbackBundle::function_or_getter> {
+ public:
+  static void Invoke(const v8::FunctionCallbackInfo<v8::Value>& info) {
+    FunctionCallbackWrapper cbwrapper(info);
+    cbwrapper.InvokeCallback();
+  }
+
+  explicit FunctionCallbackWrapper(
+      const v8::FunctionCallbackInfo<v8::Value>& cbinfo)
+      : CallbackWrapperBase(cbinfo, cbinfo.Length()) {}
+
+  napi_value GetNewTarget() override {
+    if (_cbinfo.IsConstructCall()) {
+      return v8impl::JsValueFromV8LocalValue(_cbinfo.NewTarget());
+    } else {
+      return nullptr;
+    }
+  }
+
+  /*virtual*/
+  void Args(napi_value* buffer, size_t buffer_length) override {
+    size_t i = 0;
+    size_t min = std::min(buffer_length, _args_length);
+
+    for (; i < min; i += 1) {
+      buffer[i] = v8impl::JsValueFromV8LocalValue(_cbinfo[i]);
+    }
+
+    if (i < buffer_length) {
+      napi_value undefined =
+          v8impl::JsValueFromV8LocalValue(v8::Undefined(_cbinfo.GetIsolate()));
+      for (; i < buffer_length; i += 1) {
+        buffer[i] = undefined;
+      }
+    }
+  }
+
+  /*virtual*/
+  void SetReturnValue(napi_value value) override {
+    v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+    _cbinfo.GetReturnValue().Set(val);
+  }
+};
+
+class GetterCallbackWrapper
+    : public CallbackWrapperBase<v8::PropertyCallbackInfo<v8::Value>,
+                                 &CallbackBundle::function_or_getter> {
+ public:
+  static void Invoke(v8::Local<v8::Name> property,
+                     const v8::PropertyCallbackInfo<v8::Value>& info) {
+    GetterCallbackWrapper cbwrapper(info);
+    cbwrapper.InvokeCallback();
+  }
+
+  explicit GetterCallbackWrapper(
+      const v8::PropertyCallbackInfo<v8::Value>& cbinfo)
+      : CallbackWrapperBase(cbinfo, 0) {}
+
+  /*virtual*/
+  void Args(napi_value* buffer, size_t buffer_length) override {
+    if (buffer_length > 0) {
+      napi_value undefined =
+          v8impl::JsValueFromV8LocalValue(v8::Undefined(_cbinfo.GetIsolate()));
+      for (size_t i = 0; i < buffer_length; i += 1) {
+        buffer[i] = undefined;
+      }
+    }
+  }
+
+  /*virtual*/
+  void SetReturnValue(napi_value value) override {
+    v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+    _cbinfo.GetReturnValue().Set(val);
+  }
+};
+
+class SetterCallbackWrapper
+    : public CallbackWrapperBase<v8::PropertyCallbackInfo<void>,
+                                 &CallbackBundle::setter> {
+ public:
+  static void Invoke(v8::Local<v8::Name> property,
+                     v8::Local<v8::Value> value,
+                     const v8::PropertyCallbackInfo<void>& info) {
+    SetterCallbackWrapper cbwrapper(info, value);
+    cbwrapper.InvokeCallback();
+  }
+
+  SetterCallbackWrapper(const v8::PropertyCallbackInfo<void>& cbinfo,
+                        const v8::Local<v8::Value>& value)
+      : CallbackWrapperBase(cbinfo, 1), _value(value) {}
+
+  /*virtual*/
+  void Args(napi_value* buffer, size_t buffer_length) override {
+    if (buffer_length > 0) {
+      buffer[0] = v8impl::JsValueFromV8LocalValue(_value);
+
+      if (buffer_length > 1) {
+        napi_value undefined = v8impl::JsValueFromV8LocalValue(
+            v8::Undefined(_cbinfo.GetIsolate()));
+        for (size_t i = 1; i < buffer_length; i += 1) {
+          buffer[i] = undefined;
+        }
+      }
+    }
+  }
+
+  /*virtual*/
+  void SetReturnValue(napi_value value) override {
+    // Ignore any value returned from a setter callback.
+  }
+
+ private:
+  const v8::Local<v8::Value>& _value;
+};
+
+// Creates an object to be made available to the static function callback
+// wrapper, used to retrieve the native callback function and data pointer.
+static
+v8::Local<v8::Value> CreateFunctionCallbackData(napi_env env,
+                                                napi_callback cb,
+                                                void* data) {
+  CallbackBundle* bundle = new CallbackBundle();
+  bundle->function_or_getter = cb;
+  bundle->cb_data = data;
+  bundle->env = env;
+  v8::Local<v8::Value> cbdata = v8::External::New(env->isolate, bundle);
+  bundle->BindLifecycleTo(env->isolate, cbdata);
+
+  return cbdata;
+}
+
+// Creates an object to be made available to the static getter/setter
+// callback wrapper, used to retrieve the native getter/setter callback
+// function and data pointer.
+static
+v8::Local<v8::Value> CreateAccessorCallbackData(napi_env env,
+                                                napi_callback getter,
+                                                napi_callback setter,
+                                                void* data) {
+  CallbackBundle* bundle = new CallbackBundle();
+  bundle->function_or_getter = getter;
+  bundle->setter = setter;
+  bundle->cb_data = data;
+  bundle->env = env;
+  v8::Local<v8::Value> cbdata = v8::External::New(env->isolate, bundle);
+  bundle->BindLifecycleTo(env->isolate, cbdata);
+
+  return cbdata;
+}
+
+int kWrapperFields = 3;
+
+// Pointer used to identify items wrapped by N-API. Used by FindWrapper and
+// napi_wrap().
+const char napi_wrap_name[] = "N-API Wrapper";
+
+// Search the object's prototype chain for the wrapper object. Usually the
+// wrapper would be the first in the chain, but it is OK for other objects to
+// be inserted in the prototype chain.
+static
+bool FindWrapper(v8::Local<v8::Object> obj,
+                 v8::Local<v8::Object>* result = nullptr,
+                 v8::Local<v8::Object>* parent = nullptr) {
+  v8::Local<v8::Object> wrapper = obj;
+
+  do {
+    v8::Local<v8::Value> proto = wrapper->GetPrototype();
+    if (proto.IsEmpty() || !proto->IsObject()) {
+      return false;
+    }
+    if (parent != nullptr) {
+      *parent = wrapper;
+    }
+    wrapper = proto.As<v8::Object>();
+    if (wrapper->InternalFieldCount() == kWrapperFields) {
+      v8::Local<v8::Value> external = wrapper->GetInternalField(1);
+      if (external->IsExternal() &&
+          external.As<v8::External>()->Value() == v8impl::napi_wrap_name) {
+        break;
+      }
+    }
+  } while (true);
+
+  if (result != nullptr) {
+    *result = wrapper;
+  }
+  return true;
+}
+
+static void DeleteEnv(napi_env env, void* data, void* hint) {
+  delete env;
+}
+
+static
+napi_env GetEnv(v8::Local<v8::Context> context) {
+  napi_env result;
+
+  auto isolate = context->GetIsolate();
+  auto global = context->Global();
+
+  // In the case of the string for which we grab the private and the value of
+  // the private on the global object we can call .ToLocalChecked() directly
+  // because we need to stop hard if either of them is empty.
+  //
+  // Re https://github.com/nodejs/node/pull/14217#discussion_r128775149
+  auto key = v8::Private::ForApi(isolate,
+      v8::String::NewFromOneByte(isolate,
+          reinterpret_cast<const uint8_t*>("N-API Environment"),
+          v8::NewStringType::kInternalized).ToLocalChecked());
+  auto value = global->GetPrivate(context, key).ToLocalChecked();
+
+  if (value->IsExternal()) {
+    result = static_cast<napi_env>(value.As<v8::External>()->Value());
+  } else {
+    result = new napi_env__(isolate);
+    auto external = v8::External::New(isolate, result);
+
+    // We must also stop hard if the result of assigning the env to the global
+    // is either nothing or false.
+    CHECK(global->SetPrivate(context, key, external).FromJust());
+
+    // Create a self-destructing reference to external that will get rid of the
+    // napi_env when external goes out of scope.
+    Reference::New(result, external, 0, true, DeleteEnv, nullptr, nullptr);
+  }
+
+  return result;
+}
+
+static
+napi_status Unwrap(napi_env env,
+                   napi_value js_object,
+                   void** result,
+                   v8::Local<v8::Object>* wrapper,
+                   v8::Local<v8::Object>* parent = nullptr) {
+  CHECK_ARG(env, js_object);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(js_object);
+  RETURN_STATUS_IF_FALSE(env, value->IsObject(), napi_invalid_arg);
+  v8::Local<v8::Object> obj = value.As<v8::Object>();
+
+  RETURN_STATUS_IF_FALSE(
+    env, v8impl::FindWrapper(obj, wrapper, parent), napi_invalid_arg);
+
+  v8::Local<v8::Value> unwrappedValue = (*wrapper)->GetInternalField(0);
+  RETURN_STATUS_IF_FALSE(env, unwrappedValue->IsExternal(), napi_invalid_arg);
+
+  *result = unwrappedValue.As<v8::External>()->Value();
+
+  return napi_ok;
+}
+
+static
+napi_status ConcludeDeferred(napi_env env,
+                             napi_deferred deferred,
+                             napi_value result,
+                             bool is_resolved) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Context> context = env->isolate->GetCurrentContext();
+  v8::Persistent<v8::Value>* deferred_ref =
+      V8PersistentFromJsDeferred(deferred);
+  v8::Local<v8::Value> v8_deferred =
+      v8::Local<v8::Value>::New(env->isolate, *deferred_ref);
+
+  auto v8_resolver = v8::Local<v8::Promise::Resolver>::Cast(v8_deferred);
+
+  v8::Maybe<bool> success = is_resolved ?
+      v8_resolver->Resolve(context, v8impl::V8LocalValueFromJsValue(result)) :
+      v8_resolver->Reject(context, v8impl::V8LocalValueFromJsValue(result));
+
+  deferred_ref->Reset();
+  delete deferred_ref;
+
+  RETURN_STATUS_IF_FALSE(env, success.FromMaybe(false), napi_generic_failure);
+
+  return GET_RETURN_STATUS(env);
+}
+
+}  // end of namespace v8impl
+
+// Intercepts the Node-V8 module registration callback. Converts parameters
+// to NAPI equivalents and then calls the registration callback specified
+// by the NAPI module.
+void napi_module_register_cb(v8::Local<v8::Object> exports,
+                             v8::Local<v8::Value> module,
+                             v8::Local<v8::Context> context,
+                             void* priv) {
+  napi_module* mod = static_cast<napi_module*>(priv);
+
+  // Create a new napi_env for this module or reference one if a pre-existing
+  // one is found.
+  napi_env env = v8impl::GetEnv(context);
+
+  napi_value _exports;
+  NAPI_CALL_INTO_MODULE_THROW(env,
+      _exports = mod->nm_register_func(env,
+          v8impl::JsValueFromV8LocalValue(exports)));
+
+  // If register function returned a non-null exports object different from
+  // the exports object we passed it, set that as the "exports" property of
+  // the module.
+  if (_exports != nullptr &&
+      _exports != v8impl::JsValueFromV8LocalValue(exports)) {
+    napi_value _module = v8impl::JsValueFromV8LocalValue(module);
+    napi_set_named_property(env, _module, "exports", _exports);
+  }
+}
+
+}  // end of anonymous namespace
+
+// Registers a NAPI module.
+void napi_module_register(napi_module* mod) {
+  node::node_module* nm = new node::node_module {
+    NODE_MODULE_VERSION,
+    mod->nm_flags,
+    nullptr,
+    mod->nm_filename,
+    nullptr,
+    napi_module_register_cb,
+    mod->nm_modname,
+    mod,  // priv
+    nullptr,
+  };
+  node::node_module_register(nm);
+}
+
+// Warning: Keep in-sync with napi_status enum
+static
+const char* error_messages[] = {nullptr,
+                                "Invalid argument",
+                                "An object was expected",
+                                "A string was expected",
+                                "A string or symbol was expected",
+                                "A function was expected",
+                                "A number was expected",
+                                "A boolean was expected",
+                                "An array was expected",
+                                "Unknown failure",
+                                "An exception is pending",
+                                "The async work item was cancelled",
+                                "napi_escape_handle already called on scope"};
+
+static inline napi_status napi_clear_last_error(napi_env env) {
+  env->last_error.error_code = napi_ok;
+
+  // TODO(boingoing): Should this be a callback?
+  env->last_error.engine_error_code = 0;
+  env->last_error.engine_reserved = nullptr;
+  return napi_ok;
+}
+
+static inline
+napi_status napi_set_last_error(napi_env env, napi_status error_code,
+                                uint32_t engine_error_code,
+                                void* engine_reserved) {
+  env->last_error.error_code = error_code;
+  env->last_error.engine_error_code = engine_error_code;
+  env->last_error.engine_reserved = engine_reserved;
+  return error_code;
+}
+
+napi_status napi_get_last_error_info(napi_env env,
+                                     const napi_extended_error_info** result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  // you must update this assert to reference the last message
+  // in the napi_status enum each time a new error message is added.
+  // We don't have a napi_status_last as this would result in an ABI
+  // change each time a message was added.
+  static_assert(
+      node::arraysize(error_messages) == napi_escape_called_twice + 1,
+      "Count of error messages must match count of error values");
+  CHECK_LE(env->last_error.error_code, napi_escape_called_twice);
+
+  // Wait until someone requests the last error information to fetch the error
+  // message string
+  env->last_error.error_message =
+      error_messages[env->last_error.error_code];
+
+  *result = &(env->last_error);
+  return napi_ok;
+}
+
+napi_status napi_fatal_exception(napi_env env, napi_value err) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, err);
+
+  v8::Local<v8::Value> local_err = v8impl::V8LocalValueFromJsValue(err);
+  v8impl::trigger_fatal_exception(env, local_err);
+
+  return napi_clear_last_error(env);
+}
+
+NAPI_NO_RETURN void napi_fatal_error(const char* location,
+                                     size_t location_len,
+                                     const char* message,
+                                     size_t message_len) {
+  std::string location_string;
+  std::string message_string;
+
+  if (location_len != NAPI_AUTO_LENGTH) {
+    location_string.assign(
+        const_cast<char*>(location), location_len);
+  } else {
+    location_string.assign(
+        const_cast<char*>(location), strlen(location));
+  }
+
+  if (message_len != NAPI_AUTO_LENGTH) {
+    message_string.assign(
+        const_cast<char*>(message), message_len);
+  } else {
+    message_string.assign(
+        const_cast<char*>(message), strlen(message));
+  }
+
+  node::FatalError(location_string.c_str(), message_string.c_str());
+}
+
+napi_status napi_create_function(napi_env env,
+                                 const char* utf8name,
+                                 size_t length,
+                                 napi_callback cb,
+                                 void* callback_data,
+                                 napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+  CHECK_ARG(env, cb);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Function> return_value;
+  v8::EscapableHandleScope scope(isolate);
+  v8::Local<v8::Value> cbdata =
+      v8impl::CreateFunctionCallbackData(env, cb, callback_data);
+
+  RETURN_STATUS_IF_FALSE(env, !cbdata.IsEmpty(), napi_generic_failure);
+
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::MaybeLocal<v8::Function> maybe_function =
+      v8::Function::New(context,
+                        v8impl::FunctionCallbackWrapper::Invoke,
+                        cbdata);
+  CHECK_MAYBE_EMPTY(env, maybe_function, napi_generic_failure);
+
+  return_value = scope.Escape(maybe_function.ToLocalChecked());
+
+  if (utf8name != nullptr) {
+    v8::Local<v8::String> name_string;
+    CHECK_NEW_FROM_UTF8_LEN(env, name_string, utf8name, length);
+    return_value->SetName(name_string);
+  }
+
+  *result = v8impl::JsValueFromV8LocalValue(return_value);
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_define_class(napi_env env,
+                              const char* utf8name,
+                              size_t length,
+                              napi_callback constructor,
+                              void* callback_data,
+                              size_t property_count,
+                              const napi_property_descriptor* properties,
+                              napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+  CHECK_ARG(env, constructor);
+
+  v8::Isolate* isolate = env->isolate;
+
+  v8::EscapableHandleScope scope(isolate);
+  v8::Local<v8::Value> cbdata =
+      v8impl::CreateFunctionCallbackData(env, constructor, callback_data);
+
+  RETURN_STATUS_IF_FALSE(env, !cbdata.IsEmpty(), napi_generic_failure);
+
+  v8::Local<v8::FunctionTemplate> tpl = v8::FunctionTemplate::New(
+      isolate, v8impl::FunctionCallbackWrapper::Invoke, cbdata);
+
+  v8::Local<v8::String> name_string;
+  CHECK_NEW_FROM_UTF8_LEN(env, name_string, utf8name, length);
+  tpl->SetClassName(name_string);
+
+  size_t static_property_count = 0;
+  for (size_t i = 0; i < property_count; i++) {
+    const napi_property_descriptor* p = properties + i;
+
+    if ((p->attributes & napi_static) != 0) {
+      // Static properties are handled separately below.
+      static_property_count++;
+      continue;
+    }
+
+    v8::Local<v8::Name> property_name;
+    napi_status status =
+        v8impl::V8NameFromPropertyDescriptor(env, p, &property_name);
+
+    if (status != napi_ok) {
+      return napi_set_last_error(env, status);
+    }
+
+    v8::PropertyAttribute attributes =
+        v8impl::V8PropertyAttributesFromDescriptor(p);
+
+    // This code is similar to that in napi_define_properties(); the
+    // difference is it applies to a template instead of an object.
+    if (p->getter != nullptr || p->setter != nullptr) {
+      v8::Local<v8::Value> cbdata = v8impl::CreateAccessorCallbackData(
+        env, p->getter, p->setter, p->data);
+
+      tpl->PrototypeTemplate()->SetAccessor(
+        property_name,
+        p->getter ? v8impl::GetterCallbackWrapper::Invoke : nullptr,
+        p->setter ? v8impl::SetterCallbackWrapper::Invoke : nullptr,
+        cbdata,
+        v8::AccessControl::DEFAULT,
+        attributes);
+    } else if (p->method != nullptr) {
+      v8::Local<v8::Value> cbdata =
+          v8impl::CreateFunctionCallbackData(env, p->method, p->data);
+
+      RETURN_STATUS_IF_FALSE(env, !cbdata.IsEmpty(), napi_generic_failure);
+
+      v8::Local<v8::FunctionTemplate> t =
+        v8::FunctionTemplate::New(isolate,
+          v8impl::FunctionCallbackWrapper::Invoke,
+          cbdata,
+          v8::Signature::New(isolate, tpl));
+
+      tpl->PrototypeTemplate()->Set(property_name, t, attributes);
+    } else {
+      v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(p->value);
+      tpl->PrototypeTemplate()->Set(property_name, value, attributes);
+    }
+  }
+
+  *result = v8impl::JsValueFromV8LocalValue(scope.Escape(tpl->GetFunction()));
+
+  if (static_property_count > 0) {
+    std::vector<napi_property_descriptor> static_descriptors;
+    static_descriptors.reserve(static_property_count);
+
+    for (size_t i = 0; i < property_count; i++) {
+      const napi_property_descriptor* p = properties + i;
+      if ((p->attributes & napi_static) != 0) {
+        static_descriptors.push_back(*p);
+      }
+    }
+
+    napi_status status =
+        napi_define_properties(env,
+                               *result,
+                               static_descriptors.size(),
+                               static_descriptors.data());
+    if (status != napi_ok) return status;
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_get_property_names(napi_env env,
+                                    napi_value object,
+                                    napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  auto maybe_propertynames = obj->GetPropertyNames(context);
+
+  CHECK_MAYBE_EMPTY(env, maybe_propertynames, napi_generic_failure);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      maybe_propertynames.ToLocalChecked());
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_set_property(napi_env env,
+                              napi_value object,
+                              napi_value key,
+                              napi_value value) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, key);
+  CHECK_ARG(env, value);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  v8::Local<v8::Value> k = v8impl::V8LocalValueFromJsValue(key);
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  v8::Maybe<bool> set_maybe = obj->Set(context, k, val);
+
+  RETURN_STATUS_IF_FALSE(env, set_maybe.FromMaybe(false), napi_generic_failure);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_has_property(napi_env env,
+                              napi_value object,
+                              napi_value key,
+                              bool* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+  CHECK_ARG(env, key);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  v8::Local<v8::Value> k = v8impl::V8LocalValueFromJsValue(key);
+  v8::Maybe<bool> has_maybe = obj->Has(context, k);
+
+  CHECK_MAYBE_NOTHING(env, has_maybe, napi_generic_failure);
+
+  *result = has_maybe.FromMaybe(false);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_get_property(napi_env env,
+                              napi_value object,
+                              napi_value key,
+                              napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, key);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Value> k = v8impl::V8LocalValueFromJsValue(key);
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  auto get_maybe = obj->Get(context, k);
+
+  CHECK_MAYBE_EMPTY(env, get_maybe, napi_generic_failure);
+
+  v8::Local<v8::Value> val = get_maybe.ToLocalChecked();
+  *result = v8impl::JsValueFromV8LocalValue(val);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_delete_property(napi_env env,
+                                 napi_value object,
+                                 napi_value key,
+                                 bool* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, key);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Value> k = v8impl::V8LocalValueFromJsValue(key);
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+  v8::Maybe<bool> delete_maybe = obj->Delete(context, k);
+  CHECK_MAYBE_NOTHING(env, delete_maybe, napi_generic_failure);
+
+  if (result != NULL)
+    *result = delete_maybe.FromMaybe(false);
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_has_own_property(napi_env env,
+                                  napi_value object,
+                                  napi_value key,
+                                  bool* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, key);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+  v8::Local<v8::Value> k = v8impl::V8LocalValueFromJsValue(key);
+  RETURN_STATUS_IF_FALSE(env, k->IsName(), napi_name_expected);
+  v8::Maybe<bool> has_maybe = obj->HasOwnProperty(context, k.As<v8::Name>());
+  CHECK_MAYBE_NOTHING(env, has_maybe, napi_generic_failure);
+  *result = has_maybe.FromMaybe(false);
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_set_named_property(napi_env env,
+                                    napi_value object,
+                                    const char* utf8name,
+                                    napi_value value) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, value);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  v8::Local<v8::Name> key;
+  CHECK_NEW_FROM_UTF8(env, key, utf8name);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  v8::Maybe<bool> set_maybe = obj->Set(context, key, val);
+
+  RETURN_STATUS_IF_FALSE(env, set_maybe.FromMaybe(false), napi_generic_failure);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_has_named_property(napi_env env,
+                                    napi_value object,
+                                    const char* utf8name,
+                                    bool* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  v8::Local<v8::Name> key;
+  CHECK_NEW_FROM_UTF8(env, key, utf8name);
+
+  v8::Maybe<bool> has_maybe = obj->Has(context, key);
+
+  CHECK_MAYBE_NOTHING(env, has_maybe, napi_generic_failure);
+
+  *result = has_maybe.FromMaybe(false);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_get_named_property(napi_env env,
+                                    napi_value object,
+                                    const char* utf8name,
+                                    napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Name> key;
+  CHECK_NEW_FROM_UTF8(env, key, utf8name);
+
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  auto get_maybe = obj->Get(context, key);
+
+  CHECK_MAYBE_EMPTY(env, get_maybe, napi_generic_failure);
+
+  v8::Local<v8::Value> val = get_maybe.ToLocalChecked();
+  *result = v8impl::JsValueFromV8LocalValue(val);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_set_element(napi_env env,
+                             napi_value object,
+                             uint32_t index,
+                             napi_value value) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, value);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  auto set_maybe = obj->Set(context, index, val);
+
+  RETURN_STATUS_IF_FALSE(env, set_maybe.FromMaybe(false), napi_generic_failure);
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_has_element(napi_env env,
+                             napi_value object,
+                             uint32_t index,
+                             bool* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  v8::Maybe<bool> has_maybe = obj->Has(context, index);
+
+  CHECK_MAYBE_NOTHING(env, has_maybe, napi_generic_failure);
+
+  *result = has_maybe.FromMaybe(false);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_get_element(napi_env env,
+                             napi_value object,
+                             uint32_t index,
+                             napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  auto get_maybe = obj->Get(context, index);
+
+  CHECK_MAYBE_EMPTY(env, get_maybe, napi_generic_failure);
+
+  *result = v8impl::JsValueFromV8LocalValue(get_maybe.ToLocalChecked());
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_delete_element(napi_env env,
+                                napi_value object,
+                                uint32_t index,
+                                bool* result) {
+  NAPI_PREAMBLE(env);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+
+  CHECK_TO_OBJECT(env, context, obj, object);
+  v8::Maybe<bool> delete_maybe = obj->Delete(context, index);
+  CHECK_MAYBE_NOTHING(env, delete_maybe, napi_generic_failure);
+
+  if (result != NULL)
+    *result = delete_maybe.FromMaybe(false);
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_define_properties(napi_env env,
+                                   napi_value object,
+                                   size_t property_count,
+                                   const napi_property_descriptor* properties) {
+  NAPI_PREAMBLE(env);
+  if (property_count > 0) {
+    CHECK_ARG(env, properties);
+  }
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Object> obj;
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  for (size_t i = 0; i < property_count; i++) {
+    const napi_property_descriptor* p = &properties[i];
+
+    v8::Local<v8::Name> property_name;
+    napi_status status =
+        v8impl::V8NameFromPropertyDescriptor(env, p, &property_name);
+
+    if (status != napi_ok) {
+      return napi_set_last_error(env, status);
+    }
+
+    v8::PropertyAttribute attributes =
+        v8impl::V8PropertyAttributesFromDescriptor(p);
+
+    if (p->getter != nullptr || p->setter != nullptr) {
+      v8::Local<v8::Value> cbdata = v8impl::CreateAccessorCallbackData(
+        env,
+        p->getter,
+        p->setter,
+        p->data);
+
+      auto set_maybe = obj->SetAccessor(
+        context,
+        property_name,
+        p->getter ? v8impl::GetterCallbackWrapper::Invoke : nullptr,
+        p->setter ? v8impl::SetterCallbackWrapper::Invoke : nullptr,
+        cbdata,
+        v8::AccessControl::DEFAULT,
+        attributes);
+
+      if (!set_maybe.FromMaybe(false)) {
+        return napi_set_last_error(env, napi_invalid_arg);
+      }
+    } else if (p->method != nullptr) {
+      v8::Local<v8::Value> cbdata =
+          v8impl::CreateFunctionCallbackData(env, p->method, p->data);
+
+      CHECK_MAYBE_EMPTY(env, cbdata, napi_generic_failure);
+
+      v8::MaybeLocal<v8::Function> maybe_fn =
+          v8::Function::New(context,
+                            v8impl::FunctionCallbackWrapper::Invoke,
+                            cbdata);
+
+      CHECK_MAYBE_EMPTY(env, maybe_fn, napi_generic_failure);
+
+      auto define_maybe = obj->DefineOwnProperty(
+        context, property_name, maybe_fn.ToLocalChecked(), attributes);
+
+      if (!define_maybe.FromMaybe(false)) {
+        return napi_set_last_error(env, napi_generic_failure);
+      }
+    } else {
+      v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(p->value);
+
+      auto define_maybe =
+          obj->DefineOwnProperty(context, property_name, value, attributes);
+
+      if (!define_maybe.FromMaybe(false)) {
+        return napi_set_last_error(env, napi_invalid_arg);
+      }
+    }
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_is_array(napi_env env, napi_value value, bool* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  *result = val->IsArray();
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_array_length(napi_env env,
+                                  napi_value value,
+                                  uint32_t* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  RETURN_STATUS_IF_FALSE(env, val->IsArray(), napi_array_expected);
+
+  v8::Local<v8::Array> arr = val.As<v8::Array>();
+  *result = arr->Length();
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_strict_equals(napi_env env,
+                               napi_value lhs,
+                               napi_value rhs,
+                               bool* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, lhs);
+  CHECK_ARG(env, rhs);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> a = v8impl::V8LocalValueFromJsValue(lhs);
+  v8::Local<v8::Value> b = v8impl::V8LocalValueFromJsValue(rhs);
+
+  *result = a->StrictEquals(b);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_get_prototype(napi_env env,
+                               napi_value object,
+                               napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Object> obj;
+  CHECK_TO_OBJECT(env, context, obj, object);
+
+  v8::Local<v8::Value> val = obj->GetPrototype();
+  *result = v8impl::JsValueFromV8LocalValue(val);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_create_object(napi_env env, napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Object::New(env->isolate));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_array(napi_env env, napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Array::New(env->isolate));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_array_with_length(napi_env env,
+                                          size_t length,
+                                          napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Array::New(env->isolate, length));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_string_latin1(napi_env env,
+                                      const char* str,
+                                      size_t length,
+                                      napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  auto isolate = env->isolate;
+  auto str_maybe =
+      v8::String::NewFromOneByte(isolate,
+                                 reinterpret_cast<const uint8_t*>(str),
+                                 v8::NewStringType::kInternalized,
+                                 length);
+  CHECK_MAYBE_EMPTY(env, str_maybe, napi_generic_failure);
+
+  *result = v8impl::JsValueFromV8LocalValue(str_maybe.ToLocalChecked());
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_string_utf8(napi_env env,
+                                    const char* str,
+                                    size_t length,
+                                    napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::String> s;
+  CHECK_NEW_FROM_UTF8_LEN(env, s, str, length);
+
+  *result = v8impl::JsValueFromV8LocalValue(s);
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_string_utf16(napi_env env,
+                                     const char16_t* str,
+                                     size_t length,
+                                     napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  auto isolate = env->isolate;
+  auto str_maybe =
+      v8::String::NewFromTwoByte(isolate,
+                                 reinterpret_cast<const uint16_t*>(str),
+                                 v8::NewStringType::kInternalized,
+                                 length);
+  CHECK_MAYBE_EMPTY(env, str_maybe, napi_generic_failure);
+
+  *result = v8impl::JsValueFromV8LocalValue(str_maybe.ToLocalChecked());
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_double(napi_env env,
+                               double value,
+                               napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Number::New(env->isolate, value));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_int32(napi_env env,
+                              int32_t value,
+                              napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Integer::New(env->isolate, value));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_uint32(napi_env env,
+                               uint32_t value,
+                               napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Integer::NewFromUnsigned(env->isolate, value));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_int64(napi_env env,
+                              int64_t value,
+                              napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Number::New(env->isolate, static_cast<double>(value)));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_boolean(napi_env env, bool value, napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+
+  if (value) {
+    *result = v8impl::JsValueFromV8LocalValue(v8::True(isolate));
+  } else {
+    *result = v8impl::JsValueFromV8LocalValue(v8::False(isolate));
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_symbol(napi_env env,
+                               napi_value description,
+                               napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+
+  if (description == nullptr) {
+    *result = v8impl::JsValueFromV8LocalValue(v8::Symbol::New(isolate));
+  } else {
+    v8::Local<v8::Value> desc = v8impl::V8LocalValueFromJsValue(description);
+    RETURN_STATUS_IF_FALSE(env, desc->IsString(), napi_string_expected);
+
+    *result = v8impl::JsValueFromV8LocalValue(
+      v8::Symbol::New(isolate, desc.As<v8::String>()));
+  }
+
+  return napi_clear_last_error(env);
+}
+
+static napi_status set_error_code(napi_env env,
+                                  v8::Local<v8::Value> error,
+                                  napi_value code,
+                                  const char* code_cstring) {
+  if ((code != nullptr) || (code_cstring != nullptr)) {
+    v8::Isolate* isolate = env->isolate;
+    v8::Local<v8::Context> context = isolate->GetCurrentContext();
+    v8::Local<v8::Object> err_object = error.As<v8::Object>();
+
+    v8::Local<v8::Value> code_value = v8impl::V8LocalValueFromJsValue(code);
+    if (code != nullptr) {
+      code_value = v8impl::V8LocalValueFromJsValue(code);
+      RETURN_STATUS_IF_FALSE(env, code_value->IsString(), napi_string_expected);
+    } else {
+      CHECK_NEW_FROM_UTF8(env, code_value, code_cstring);
+    }
+
+    v8::Local<v8::Name> code_key;
+    CHECK_NEW_FROM_UTF8(env, code_key, "code");
+
+    v8::Maybe<bool> set_maybe = err_object->Set(context, code_key, code_value);
+    RETURN_STATUS_IF_FALSE(env,
+                           set_maybe.FromMaybe(false),
+                           napi_generic_failure);
+
+    // now update the name to be "name [code]" where name is the
+    // original name and code is the code associated with the Error
+    v8::Local<v8::String> name_string;
+    CHECK_NEW_FROM_UTF8(env, name_string, "");
+    v8::Local<v8::Name> name_key;
+    CHECK_NEW_FROM_UTF8(env, name_key, "name");
+
+    auto maybe_name = err_object->Get(context, name_key);
+    if (!maybe_name.IsEmpty()) {
+      v8::Local<v8::Value> name = maybe_name.ToLocalChecked();
+      if (name->IsString()) {
+        name_string = v8::String::Concat(name_string, name.As<v8::String>());
+      }
+    }
+    name_string = v8::String::Concat(name_string,
+                                     FIXED_ONE_BYTE_STRING(isolate, " ["));
+    name_string = v8::String::Concat(name_string, code_value.As<v8::String>());
+    name_string = v8::String::Concat(name_string,
+                                     FIXED_ONE_BYTE_STRING(isolate, "]"));
+
+    set_maybe = err_object->Set(context, name_key, name_string);
+    RETURN_STATUS_IF_FALSE(env,
+                           set_maybe.FromMaybe(false),
+                           napi_generic_failure);
+  }
+  return napi_ok;
+}
+
+napi_status napi_create_error(napi_env env,
+                              napi_value code,
+                              napi_value msg,
+                              napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, msg);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> message_value = v8impl::V8LocalValueFromJsValue(msg);
+  RETURN_STATUS_IF_FALSE(env, message_value->IsString(), napi_string_expected);
+
+  v8::Local<v8::Value> error_obj =
+      v8::Exception::Error(message_value.As<v8::String>());
+  napi_status status = set_error_code(env, error_obj, code, nullptr);
+  if (status != napi_ok) return status;
+
+  *result = v8impl::JsValueFromV8LocalValue(error_obj);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_type_error(napi_env env,
+                                   napi_value code,
+                                   napi_value msg,
+                                   napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, msg);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> message_value = v8impl::V8LocalValueFromJsValue(msg);
+  RETURN_STATUS_IF_FALSE(env, message_value->IsString(), napi_string_expected);
+
+  v8::Local<v8::Value> error_obj =
+      v8::Exception::TypeError(message_value.As<v8::String>());
+  napi_status status = set_error_code(env, error_obj, code, nullptr);
+  if (status != napi_ok) return status;
+
+  *result = v8impl::JsValueFromV8LocalValue(error_obj);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_range_error(napi_env env,
+                                    napi_value code,
+                                    napi_value msg,
+                                    napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, msg);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> message_value = v8impl::V8LocalValueFromJsValue(msg);
+  RETURN_STATUS_IF_FALSE(env, message_value->IsString(), napi_string_expected);
+
+  v8::Local<v8::Value> error_obj =
+      v8::Exception::RangeError(message_value.As<v8::String>());
+  napi_status status = set_error_code(env, error_obj, code, nullptr);
+  if (status != napi_ok) return status;
+
+  *result = v8impl::JsValueFromV8LocalValue(error_obj);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_typeof(napi_env env,
+                        napi_value value,
+                        napi_valuetype* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> v = v8impl::V8LocalValueFromJsValue(value);
+
+  if (v->IsNumber()) {
+    *result = napi_number;
+  } else if (v->IsString()) {
+    *result = napi_string;
+  } else if (v->IsFunction()) {
+    // This test has to come before IsObject because IsFunction
+    // implies IsObject
+    *result = napi_function;
+  } else if (v->IsExternal()) {
+    // This test has to come before IsObject because IsExternal
+    // implies IsObject
+    *result = napi_external;
+  } else if (v->IsObject()) {
+    *result = napi_object;
+  } else if (v->IsBoolean()) {
+    *result = napi_boolean;
+  } else if (v->IsUndefined()) {
+    *result = napi_undefined;
+  } else if (v->IsSymbol()) {
+    *result = napi_symbol;
+  } else if (v->IsNull()) {
+    *result = napi_null;
+  } else {
+    // Should not get here unless V8 has added some new kind of value.
+    return napi_set_last_error(env, napi_invalid_arg);
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_undefined(napi_env env, napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+      v8::Undefined(env->isolate));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_null(napi_env env, napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsValueFromV8LocalValue(
+        v8::Null(env->isolate));
+
+  return napi_clear_last_error(env);
+}
+
+// Gets all callback info in a single call. (Ugly, but faster.)
+napi_status napi_get_cb_info(
+    napi_env env,               // [in] NAPI environment handle
+    napi_callback_info cbinfo,  // [in] Opaque callback-info handle
+    size_t* argc,      // [in-out] Specifies the size of the provided argv array
+                       // and receives the actual count of args.
+    napi_value* argv,  // [out] Array of values
+    napi_value* this_arg,  // [out] Receives the JS 'this' arg for the call
+    void** data) {         // [out] Receives the data pointer for the callback.
+  CHECK_ENV(env);
+  CHECK_ARG(env, cbinfo);
+
+  v8impl::CallbackWrapper* info =
+      reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);
+
+  if (argv != nullptr) {
+    CHECK_ARG(env, argc);
+    info->Args(argv, *argc);
+  }
+  if (argc != nullptr) {
+    *argc = info->ArgsLength();
+  }
+  if (this_arg != nullptr) {
+    *this_arg = info->This();
+  }
+  if (data != nullptr) {
+    *data = info->Data();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_new_target(napi_env env,
+                                napi_callback_info cbinfo,
+                                napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, cbinfo);
+  CHECK_ARG(env, result);
+
+  v8impl::CallbackWrapper* info =
+      reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);
+
+  *result = info->GetNewTarget();
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_call_function(napi_env env,
+                               napi_value recv,
+                               napi_value func,
+                               size_t argc,
+                               const napi_value* argv,
+                               napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, recv);
+  if (argc > 0) {
+    CHECK_ARG(env, argv);
+  }
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Value> v8recv = v8impl::V8LocalValueFromJsValue(recv);
+
+  v8::Local<v8::Function> v8func;
+  CHECK_TO_FUNCTION(env, v8func, func);
+
+  auto maybe = v8func->Call(context, v8recv, argc,
+    reinterpret_cast<v8::Local<v8::Value>*>(const_cast<napi_value*>(argv)));
+
+  if (try_catch.HasCaught()) {
+    return napi_set_last_error(env, napi_pending_exception);
+  } else {
+    if (result != nullptr) {
+      CHECK_MAYBE_EMPTY(env, maybe, napi_generic_failure);
+      *result = v8impl::JsValueFromV8LocalValue(maybe.ToLocalChecked());
+    }
+    return napi_clear_last_error(env);
+  }
+}
+
+napi_status napi_get_global(napi_env env, napi_value* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  // TODO(ianhall): what if we need the global object from a different
+  // context in the same isolate?
+  // Should napi_env be the current context rather than the current isolate?
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  *result = v8impl::JsValueFromV8LocalValue(context->Global());
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_throw(napi_env env, napi_value error) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, error);
+
+  v8::Isolate* isolate = env->isolate;
+
+  isolate->ThrowException(v8impl::V8LocalValueFromJsValue(error));
+  // any VM calls after this point and before returning
+  // to the javascript invoker will fail
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_throw_error(napi_env env,
+                             const char* code,
+                             const char* msg) {
+  NAPI_PREAMBLE(env);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::String> str;
+  CHECK_NEW_FROM_UTF8(env, str, msg);
+
+  v8::Local<v8::Value> error_obj = v8::Exception::Error(str);
+  napi_status status = set_error_code(env, error_obj, nullptr, code);
+  if (status != napi_ok) return status;
+
+  isolate->ThrowException(error_obj);
+  // any VM calls after this point and before returning
+  // to the javascript invoker will fail
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_throw_type_error(napi_env env,
+                                  const char* code,
+                                  const char* msg) {
+  NAPI_PREAMBLE(env);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::String> str;
+  CHECK_NEW_FROM_UTF8(env, str, msg);
+
+  v8::Local<v8::Value> error_obj = v8::Exception::TypeError(str);
+  napi_status status = set_error_code(env, error_obj, nullptr, code);
+  if (status != napi_ok) return status;
+
+  isolate->ThrowException(error_obj);
+  // any VM calls after this point and before returning
+  // to the javascript invoker will fail
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_throw_range_error(napi_env env,
+                                   const char* code,
+                                   const char* msg) {
+  NAPI_PREAMBLE(env);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::String> str;
+  CHECK_NEW_FROM_UTF8(env, str, msg);
+
+  v8::Local<v8::Value> error_obj = v8::Exception::RangeError(str);
+  napi_status status = set_error_code(env, error_obj, nullptr, code);
+  if (status != napi_ok) return status;
+
+  isolate->ThrowException(error_obj);
+  // any VM calls after this point and before returning
+  // to the javascript invoker will fail
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_is_error(napi_env env, napi_value value, bool* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot
+  // throw JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  *result = val->IsNativeError();
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_double(napi_env env,
+                                  napi_value value,
+                                  double* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  RETURN_STATUS_IF_FALSE(env, val->IsNumber(), napi_number_expected);
+
+  *result = val.As<v8::Number>()->Value();
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_int32(napi_env env,
+                                 napi_value value,
+                                 int32_t* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  if (val->IsInt32()) {
+    *result = val.As<v8::Int32>()->Value();
+  } else {
+    RETURN_STATUS_IF_FALSE(env, val->IsNumber(), napi_number_expected);
+
+    // Empty context: https://github.com/nodejs/node/issues/14379
+    v8::Local<v8::Context> context;
+    *result = val->Int32Value(context).FromJust();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_uint32(napi_env env,
+                                  napi_value value,
+                                  uint32_t* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  if (val->IsUint32()) {
+    *result = val.As<v8::Uint32>()->Value();
+  } else {
+    RETURN_STATUS_IF_FALSE(env, val->IsNumber(), napi_number_expected);
+
+    // Empty context: https://github.com/nodejs/node/issues/14379
+    v8::Local<v8::Context> context;
+    *result = val->Uint32Value(context).FromJust();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_int64(napi_env env,
+                                 napi_value value,
+                                 int64_t* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+
+  // This is still a fast path very likely to be taken.
+  if (val->IsInt32()) {
+    *result = val.As<v8::Int32>()->Value();
+    return napi_clear_last_error(env);
+  }
+
+  RETURN_STATUS_IF_FALSE(env, val->IsNumber(), napi_number_expected);
+
+  // v8::Value::IntegerValue() converts NaN to INT64_MIN, inconsistent with
+  // v8::Value::Int32Value() that converts NaN to 0. So special-case NaN here.
+  double doubleValue = val.As<v8::Number>()->Value();
+  if (std::isnan(doubleValue)) {
+    *result = 0;
+  } else {
+    // Empty context: https://github.com/nodejs/node/issues/14379
+    v8::Local<v8::Context> context;
+    *result = val->IntegerValue(context).FromJust();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_bool(napi_env env, napi_value value, bool* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  RETURN_STATUS_IF_FALSE(env, val->IsBoolean(), napi_boolean_expected);
+
+  *result = val.As<v8::Boolean>()->Value();
+
+  return napi_clear_last_error(env);
+}
+
+// Copies a JavaScript string into a LATIN-1 string buffer. The result is the
+// number of bytes (excluding the null terminator) copied into buf.
+// A sufficient buffer size should be greater than the length of string,
+// reserving space for null terminator.
+// If bufsize is insufficient, the string will be truncated and null terminated.
+// If buf is NULL, this method returns the length of the string (in bytes)
+// via the result parameter.
+// The result argument is optional unless buf is NULL.
+napi_status napi_get_value_string_latin1(napi_env env,
+                                         napi_value value,
+                                         char* buf,
+                                         size_t bufsize,
+                                         size_t* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  RETURN_STATUS_IF_FALSE(env, val->IsString(), napi_string_expected);
+
+  if (!buf) {
+    CHECK_ARG(env, result);
+    *result = val.As<v8::String>()->Length();
+  } else {
+    int copied = val.As<v8::String>()->WriteOneByte(
+      reinterpret_cast<uint8_t*>(buf), 0, bufsize - 1,
+      v8::String::NO_NULL_TERMINATION);
+
+    buf[copied] = '\0';
+    if (result != nullptr) {
+      *result = copied;
+    }
+  }
+
+  return napi_clear_last_error(env);
+}
+
+// Copies a JavaScript string into a UTF-8 string buffer. The result is the
+// number of bytes (excluding the null terminator) copied into buf.
+// A sufficient buffer size should be greater than the length of string,
+// reserving space for null terminator.
+// If bufsize is insufficient, the string will be truncated and null terminated.
+// If buf is NULL, this method returns the length of the string (in bytes)
+// via the result parameter.
+// The result argument is optional unless buf is NULL.
+napi_status napi_get_value_string_utf8(napi_env env,
+                                       napi_value value,
+                                       char* buf,
+                                       size_t bufsize,
+                                       size_t* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  RETURN_STATUS_IF_FALSE(env, val->IsString(), napi_string_expected);
+
+  if (!buf) {
+    CHECK_ARG(env, result);
+    *result = val.As<v8::String>()->Utf8Length();
+  } else {
+    int copied = val.As<v8::String>()->WriteUtf8(
+      buf, bufsize - 1, nullptr, v8::String::REPLACE_INVALID_UTF8 |
+      v8::String::NO_NULL_TERMINATION);
+
+    buf[copied] = '\0';
+    if (result != nullptr) {
+      *result = copied;
+    }
+  }
+
+  return napi_clear_last_error(env);
+}
+
+// Copies a JavaScript string into a UTF-16 string buffer. The result is the
+// number of 2-byte code units (excluding the null terminator) copied into buf.
+// A sufficient buffer size should be greater than the length of string,
+// reserving space for null terminator.
+// If bufsize is insufficient, the string will be truncated and null terminated.
+// If buf is NULL, this method returns the length of the string (in 2-byte
+// code units) via the result parameter.
+// The result argument is optional unless buf is NULL.
+napi_status napi_get_value_string_utf16(napi_env env,
+                                        napi_value value,
+                                        char16_t* buf,
+                                        size_t bufsize,
+                                        size_t* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  RETURN_STATUS_IF_FALSE(env, val->IsString(), napi_string_expected);
+
+  if (!buf) {
+    CHECK_ARG(env, result);
+    // V8 assumes UTF-16 length is the same as the number of characters.
+    *result = val.As<v8::String>()->Length();
+  } else {
+    int copied = val.As<v8::String>()->Write(
+      reinterpret_cast<uint16_t*>(buf), 0, bufsize - 1,
+      v8::String::NO_NULL_TERMINATION);
+
+    buf[copied] = '\0';
+    if (result != nullptr) {
+      *result = copied;
+    }
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_coerce_to_object(napi_env env,
+                                  napi_value value,
+                                  napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Object> obj;
+  CHECK_TO_OBJECT(env, context, obj, value);
+
+  *result = v8impl::JsValueFromV8LocalValue(obj);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_coerce_to_bool(napi_env env,
+                                napi_value value,
+                                napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Boolean> b;
+
+  CHECK_TO_BOOL(env, context, b, value);
+
+  *result = v8impl::JsValueFromV8LocalValue(b);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_coerce_to_number(napi_env env,
+                                  napi_value value,
+                                  napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::Number> num;
+
+  CHECK_TO_NUMBER(env, context, num, value);
+
+  *result = v8impl::JsValueFromV8LocalValue(num);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_coerce_to_string(napi_env env,
+                                  napi_value value,
+                                  napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  v8::Local<v8::String> str;
+
+  CHECK_TO_STRING(env, context, str, value);
+
+  *result = v8impl::JsValueFromV8LocalValue(str);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_wrap(napi_env env,
+                      napi_value js_object,
+                      void* native_object,
+                      napi_finalize finalize_cb,
+                      void* finalize_hint,
+                      napi_ref* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, js_object);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(js_object);
+  RETURN_STATUS_IF_FALSE(env, value->IsObject(), napi_invalid_arg);
+  v8::Local<v8::Object> obj = value.As<v8::Object>();
+
+  // If we've already wrapped this object, we error out.
+  RETURN_STATUS_IF_FALSE(env, !v8impl::FindWrapper(obj), napi_invalid_arg);
+
+  // Create a wrapper object with an internal field to hold the wrapped pointer
+  // and a second internal field to identify the owner as N-API.
+  v8::Local<v8::ObjectTemplate> wrapper_template;
+  ENV_OBJECT_TEMPLATE(env, wrap, wrapper_template, v8impl::kWrapperFields);
+
+  auto maybe_object = wrapper_template->NewInstance(context);
+  CHECK_MAYBE_EMPTY(env, maybe_object, napi_generic_failure);
+  v8::Local<v8::Object> wrapper = maybe_object.ToLocalChecked();
+
+  // Store the pointer as an external in the wrapper.
+  wrapper->SetInternalField(0, v8::External::New(isolate, native_object));
+  wrapper->SetInternalField(1, v8::External::New(isolate,
+    reinterpret_cast<void*>(const_cast<char*>(v8impl::napi_wrap_name))));
+
+  // Insert the wrapper into the object's prototype chain.
+  v8::Local<v8::Value> proto = obj->GetPrototype();
+  CHECK(wrapper->SetPrototype(context, proto).FromJust());
+  CHECK(obj->SetPrototype(context, wrapper).FromJust());
+
+  v8impl::Reference* reference = nullptr;
+  if (result != nullptr) {
+    // The returned reference should be deleted via napi_delete_reference()
+    // ONLY in response to the finalize callback invocation. (If it is deleted
+    // before then, then the finalize callback will never be invoked.)
+    // Therefore a finalize callback is required when returning a reference.
+    CHECK_ARG(env, finalize_cb);
+    reference = v8impl::Reference::New(
+        env, obj, 0, false, finalize_cb, native_object, finalize_hint);
+    *result = reinterpret_cast<napi_ref>(reference);
+  } else if (finalize_cb != nullptr) {
+    // Create a self-deleting reference just for the finalize callback.
+    reference = v8impl::Reference::New(
+        env, obj, 0, true, finalize_cb, native_object, finalize_hint);
+  }
+
+  if (reference != nullptr) {
+    wrapper->SetInternalField(2, v8::External::New(isolate, reference));
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_unwrap(napi_env env, napi_value obj, void** result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  v8::Local<v8::Object> wrapper;
+  return napi_set_last_error(env, v8impl::Unwrap(env, obj, result, &wrapper));
+}
+
+napi_status napi_remove_wrap(napi_env env, napi_value obj, void** result) {
+  NAPI_PREAMBLE(env);
+  v8::Local<v8::Object> wrapper;
+  v8::Local<v8::Object> parent;
+  napi_status status = v8impl::Unwrap(env, obj, result, &wrapper, &parent);
+  if (status != napi_ok) {
+    return napi_set_last_error(env, status);
+  }
+
+  v8::Local<v8::Value> external = wrapper->GetInternalField(2);
+  if (external->IsExternal()) {
+    v8impl::Reference::Delete(
+        static_cast<v8impl::Reference*>(external.As<v8::External>()->Value()));
+  }
+
+  if (!parent.IsEmpty()) {
+    v8::Maybe<bool> maybe = parent->SetPrototype(
+        env->isolate->GetCurrentContext(), wrapper->GetPrototype());
+    CHECK_MAYBE_NOTHING(env, maybe, napi_generic_failure);
+    if (!maybe.FromMaybe(false)) {
+      return napi_set_last_error(env, napi_generic_failure);
+    }
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_create_external(napi_env env,
+                                 void* data,
+                                 napi_finalize finalize_cb,
+                                 void* finalize_hint,
+                                 napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+
+  v8::Local<v8::Value> external_value = v8::External::New(isolate, data);
+
+  // The Reference object will delete itself after invoking the finalizer
+  // callback.
+  v8impl::Reference::New(env,
+      external_value,
+      0,
+      true,
+      finalize_cb,
+      data,
+      finalize_hint);
+
+  *result = v8impl::JsValueFromV8LocalValue(external_value);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_value_external(napi_env env,
+                                    napi_value value,
+                                    void** result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  RETURN_STATUS_IF_FALSE(env, val->IsExternal(), napi_invalid_arg);
+
+  v8::Local<v8::External> external_value = val.As<v8::External>();
+  *result = external_value->Value();
+
+  return napi_clear_last_error(env);
+}
+
+// Set initial_refcount to 0 for a weak reference, >0 for a strong reference.
+napi_status napi_create_reference(napi_env env,
+                                  napi_value value,
+                                  uint32_t initial_refcount,
+                                  napi_ref* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> v8_value = v8impl::V8LocalValueFromJsValue(value);
+
+  if (!(v8_value->IsObject() || v8_value->IsFunction())) {
+    return napi_set_last_error(env, napi_object_expected);
+  }
+
+  v8impl::Reference* reference =
+      v8impl::Reference::New(env, v8_value, initial_refcount, false);
+
+  *result = reinterpret_cast<napi_ref>(reference);
+  return napi_clear_last_error(env);
+}
+
+// Deletes a reference. The referenced value is released, and may be GC'd unless
+// there are other references to it.
+napi_status napi_delete_reference(napi_env env, napi_ref ref) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, ref);
+
+  v8impl::Reference::Delete(reinterpret_cast<v8impl::Reference*>(ref));
+
+  return napi_clear_last_error(env);
+}
+
+// Increments the reference count, optionally returning the resulting count.
+// After this call the reference will be a strong reference because its
+// refcount is >0, and the referenced object is effectively "pinned".
+// Calling this when the refcount is 0 and the object is unavailable
+// results in an error.
+napi_status napi_reference_ref(napi_env env, napi_ref ref, uint32_t* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, ref);
+
+  v8impl::Reference* reference = reinterpret_cast<v8impl::Reference*>(ref);
+  uint32_t count = reference->Ref();
+
+  if (result != nullptr) {
+    *result = count;
+  }
+
+  return napi_clear_last_error(env);
+}
+
+// Decrements the reference count, optionally returning the resulting count. If
+// the result is 0 the reference is now weak and the object may be GC'd at any
+// time if there are no other references. Calling this when the refcount is
+// already 0 results in an error.
+napi_status napi_reference_unref(napi_env env, napi_ref ref, uint32_t* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, ref);
+
+  v8impl::Reference* reference = reinterpret_cast<v8impl::Reference*>(ref);
+
+  if (reference->RefCount() == 0) {
+    return napi_set_last_error(env, napi_generic_failure);
+  }
+
+  uint32_t count = reference->Unref();
+
+  if (result != nullptr) {
+    *result = count;
+  }
+
+  return napi_clear_last_error(env);
+}
+
+// Attempts to get a referenced value. If the reference is weak, the value might
+// no longer be available, in that case the call is still successful but the
+// result is NULL.
+napi_status napi_get_reference_value(napi_env env,
+                                     napi_ref ref,
+                                     napi_value* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, ref);
+  CHECK_ARG(env, result);
+
+  v8impl::Reference* reference = reinterpret_cast<v8impl::Reference*>(ref);
+  *result = v8impl::JsValueFromV8LocalValue(reference->Get());
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_open_handle_scope(napi_env env, napi_handle_scope* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsHandleScopeFromV8HandleScope(
+      new v8impl::HandleScopeWrapper(env->isolate));
+  env->open_handle_scopes++;
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_close_handle_scope(napi_env env, napi_handle_scope scope) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, scope);
+  if (env->open_handle_scopes == 0) {
+    return napi_handle_scope_mismatch;
+  }
+
+  env->open_handle_scopes--;
+  delete v8impl::V8HandleScopeFromJsHandleScope(scope);
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_open_escapable_handle_scope(
+    napi_env env,
+    napi_escapable_handle_scope* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = v8impl::JsEscapableHandleScopeFromV8EscapableHandleScope(
+      new v8impl::EscapableHandleScopeWrapper(env->isolate));
+  env->open_handle_scopes++;
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_close_escapable_handle_scope(
+    napi_env env,
+    napi_escapable_handle_scope scope) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, scope);
+  if (env->open_handle_scopes == 0) {
+    return napi_handle_scope_mismatch;
+  }
+
+  delete v8impl::V8EscapableHandleScopeFromJsEscapableHandleScope(scope);
+  env->open_handle_scopes--;
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_escape_handle(napi_env env,
+                               napi_escapable_handle_scope scope,
+                               napi_value escapee,
+                               napi_value* result) {
+  // Omit NAPI_PREAMBLE and GET_RETURN_STATUS because V8 calls here cannot throw
+  // JS exceptions.
+  CHECK_ENV(env);
+  CHECK_ARG(env, scope);
+  CHECK_ARG(env, escapee);
+  CHECK_ARG(env, result);
+
+  v8impl::EscapableHandleScopeWrapper* s =
+      v8impl::V8EscapableHandleScopeFromJsEscapableHandleScope(scope);
+  if (!s->escape_called()) {
+    *result = v8impl::JsValueFromV8LocalValue(
+        s->Escape(v8impl::V8LocalValueFromJsValue(escapee)));
+    return napi_clear_last_error(env);
+  }
+  return napi_set_last_error(env, napi_escape_called_twice);
+}
+
+napi_status napi_new_instance(napi_env env,
+                              napi_value constructor,
+                              size_t argc,
+                              const napi_value* argv,
+                              napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, constructor);
+  if (argc > 0) {
+    CHECK_ARG(env, argv);
+  }
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Function> ctor;
+  CHECK_TO_FUNCTION(env, ctor, constructor);
+
+  auto maybe = ctor->NewInstance(context, argc,
+    reinterpret_cast<v8::Local<v8::Value>*>(const_cast<napi_value*>(argv)));
+
+  CHECK_MAYBE_EMPTY(env, maybe, napi_generic_failure);
+
+  *result = v8impl::JsValueFromV8LocalValue(maybe.ToLocalChecked());
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_instanceof(napi_env env,
+                            napi_value object,
+                            napi_value constructor,
+                            bool* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, object);
+  CHECK_ARG(env, result);
+
+  *result = false;
+
+  v8::Local<v8::Object> ctor;
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  CHECK_TO_OBJECT(env, context, ctor, constructor);
+
+  if (!ctor->IsFunction()) {
+    napi_throw_type_error(env,
+                          "ERR_NAPI_CONS_FUNCTION",
+                          "Constructor must be a function");
+
+    return napi_set_last_error(env, napi_function_expected);
+  }
+
+  if (env->has_instance_available) {
+    napi_value value, js_result = nullptr, has_instance = nullptr;
+    napi_status status = napi_generic_failure;
+    napi_valuetype value_type;
+
+    // Get "Symbol" from the global object
+    if (env->has_instance.IsEmpty()) {
+      status = napi_get_global(env, &value);
+      if (status != napi_ok) return status;
+      status = napi_get_named_property(env, value, "Symbol", &value);
+      if (status != napi_ok) return status;
+      status = napi_typeof(env, value, &value_type);
+      if (status != napi_ok) return status;
+
+      // Get "hasInstance" from Symbol
+      if (value_type == napi_function) {
+        status = napi_get_named_property(env, value, "hasInstance", &value);
+        if (status != napi_ok) return status;
+        status = napi_typeof(env, value, &value_type);
+        if (status != napi_ok) return status;
+
+        // Store Symbol.hasInstance in a global persistent reference
+        if (value_type == napi_symbol) {
+          env->has_instance.Reset(env->isolate,
+              v8impl::V8LocalValueFromJsValue(value));
+          has_instance = value;
+        }
+      }
+    } else {
+      has_instance = v8impl::JsValueFromV8LocalValue(
+          v8::Local<v8::Value>::New(env->isolate, env->has_instance));
+    }
+
+    if (has_instance) {
+      status = napi_get_property(env, constructor, has_instance, &value);
+      if (status != napi_ok) return status;
+      status = napi_typeof(env, value, &value_type);
+      if (status != napi_ok) return status;
+
+      // Call the function to determine whether the object is an instance of the
+      // constructor
+      if (value_type == napi_function) {
+        status = napi_call_function(env, constructor, value, 1, &object,
+          &js_result);
+        if (status != napi_ok) return status;
+        return napi_get_value_bool(env, js_result, result);
+      }
+    }
+
+    env->has_instance_available = false;
+  }
+
+  // If running constructor[Symbol.hasInstance](object) did not work, we perform
+  // a traditional instanceof (early Node.js 6.x).
+
+  v8::Local<v8::String> prototype_string;
+  CHECK_NEW_FROM_UTF8(env, prototype_string, "prototype");
+
+  auto maybe_prototype = ctor->Get(context, prototype_string);
+  CHECK_MAYBE_EMPTY(env, maybe_prototype, napi_generic_failure);
+
+  v8::Local<v8::Value> prototype_property = maybe_prototype.ToLocalChecked();
+  if (!prototype_property->IsObject()) {
+    napi_throw_type_error(
+        env,
+        "ERR_NAPI_CONS_PROTOTYPE_OBJECT",
+        "Constructor.prototype must be an object");
+
+    return napi_set_last_error(env, napi_object_expected);
+  }
+
+  auto maybe_ctor = prototype_property->ToObject(context);
+  CHECK_MAYBE_EMPTY(env, maybe_ctor, napi_generic_failure);
+  ctor = maybe_ctor.ToLocalChecked();
+
+  v8::Local<v8::Value> current_obj = v8impl::V8LocalValueFromJsValue(object);
+  if (!current_obj->StrictEquals(ctor)) {
+    for (v8::Local<v8::Value> original_obj = current_obj;
+         !(current_obj->IsNull() || current_obj->IsUndefined());) {
+      if (current_obj->StrictEquals(ctor)) {
+        *result = !(original_obj->IsNumber() ||
+                    original_obj->IsBoolean() ||
+                    original_obj->IsString());
+        break;
+      }
+      v8::Local<v8::Object> obj;
+      CHECK_TO_OBJECT(env, context, obj, v8impl::JsValueFromV8LocalValue(
+        current_obj));
+      current_obj = obj->GetPrototype();
+    }
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_async_init(napi_env env,
+                            napi_value async_resource,
+                            napi_value async_resource_name,
+                            napi_async_context* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, async_resource_name);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Object> v8_resource;
+  if (async_resource != nullptr) {
+    CHECK_TO_OBJECT(env, context, v8_resource, async_resource);
+  } else {
+    v8_resource = v8::Object::New(isolate);
+  }
+
+  v8::Local<v8::String> v8_resource_name;
+  CHECK_TO_STRING(env, context, v8_resource_name, async_resource_name);
+
+  // TODO(jasongin): Consider avoiding allocation here by using
+  // a tagged pointer with 2×31 bit fields instead.
+  node::async_context* async_context = new node::async_context();
+
+  *async_context = node::EmitAsyncInit(isolate, v8_resource, v8_resource_name);
+  *result = reinterpret_cast<napi_async_context>(async_context);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_async_destroy(napi_env env,
+                               napi_async_context async_context) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, async_context);
+
+  v8::Isolate* isolate = env->isolate;
+  node::async_context* node_async_context =
+      reinterpret_cast<node::async_context*>(async_context);
+  node::EmitAsyncDestroy(isolate, *node_async_context);
+
+  delete node_async_context;
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_make_callback(napi_env env,
+                               napi_async_context async_context,
+                               napi_value recv,
+                               napi_value func,
+                               size_t argc,
+                               const napi_value* argv,
+                               napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, recv);
+  if (argc > 0) {
+    CHECK_ARG(env, argv);
+  }
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+
+  v8::Local<v8::Object> v8recv;
+  CHECK_TO_OBJECT(env, context, v8recv, recv);
+
+  v8::Local<v8::Function> v8func;
+  CHECK_TO_FUNCTION(env, v8func, func);
+
+  node::async_context* node_async_context =
+    reinterpret_cast<node::async_context*>(async_context);
+  if (node_async_context == nullptr) {
+    static node::async_context empty_context = { 0, 0 };
+    node_async_context = &empty_context;
+  }
+
+  v8::MaybeLocal<v8::Value> callback_result = node::MakeCallback(
+      isolate, v8recv, v8func, argc,
+      reinterpret_cast<v8::Local<v8::Value>*>(const_cast<napi_value*>(argv)),
+      *node_async_context);
+  CHECK_MAYBE_EMPTY(env, callback_result, napi_generic_failure);
+
+  if (result != nullptr) {
+    *result = v8impl::JsValueFromV8LocalValue(
+        callback_result.ToLocalChecked());
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+// Methods to support catching exceptions
+napi_status napi_is_exception_pending(napi_env env, bool* result) {
+  // NAPI_PREAMBLE is not used here: this function must execute when there is a
+  // pending exception.
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  *result = !env->last_exception.IsEmpty();
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_and_clear_last_exception(napi_env env,
+                                              napi_value* result) {
+  // NAPI_PREAMBLE is not used here: this function must execute when there is a
+  // pending exception.
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+
+  if (env->last_exception.IsEmpty()) {
+    return napi_get_undefined(env, result);
+  } else {
+    *result = v8impl::JsValueFromV8LocalValue(
+      v8::Local<v8::Value>::New(env->isolate, env->last_exception));
+    env->last_exception.Reset();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_buffer(napi_env env,
+                               size_t length,
+                               void** data,
+                               napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  auto maybe = node::Buffer::New(env->isolate, length);
+
+  CHECK_MAYBE_EMPTY(env, maybe, napi_generic_failure);
+
+  v8::Local<v8::Object> buffer = maybe.ToLocalChecked();
+
+  *result = v8impl::JsValueFromV8LocalValue(buffer);
+
+  if (data != nullptr) {
+    *data = node::Buffer::Data(buffer);
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_create_external_buffer(napi_env env,
+                                        size_t length,
+                                        void* data,
+                                        napi_finalize finalize_cb,
+                                        void* finalize_hint,
+                                        napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+
+  // The finalizer object will delete itself after invoking the callback.
+  v8impl::Finalizer* finalizer = v8impl::Finalizer::New(
+    env, finalize_cb, nullptr, finalize_hint);
+
+  auto maybe = node::Buffer::New(isolate,
+                                 static_cast<char*>(data),
+                                 length,
+                                 v8impl::Finalizer::FinalizeBufferCallback,
+                                 finalizer);
+
+  CHECK_MAYBE_EMPTY(env, maybe, napi_generic_failure);
+
+  *result = v8impl::JsValueFromV8LocalValue(maybe.ToLocalChecked());
+  return GET_RETURN_STATUS(env);
+  // Tell coverity that 'finalizer' should not be freed when we return
+  // as it will be deleted when the buffer to which it is associated
+  // is finalized.
+  // coverity[leaked_storage]
+}
+
+napi_status napi_create_buffer_copy(napi_env env,
+                                    size_t length,
+                                    const void* data,
+                                    void** result_data,
+                                    napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  auto maybe = node::Buffer::Copy(env->isolate,
+    static_cast<const char*>(data), length);
+
+  CHECK_MAYBE_EMPTY(env, maybe, napi_generic_failure);
+
+  v8::Local<v8::Object> buffer = maybe.ToLocalChecked();
+  *result = v8impl::JsValueFromV8LocalValue(buffer);
+
+  if (result_data != nullptr) {
+    *result_data = node::Buffer::Data(buffer);
+  }
+
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_is_buffer(napi_env env, napi_value value, bool* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  *result = node::Buffer::HasInstance(v8impl::V8LocalValueFromJsValue(value));
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_buffer_info(napi_env env,
+                                 napi_value value,
+                                 void** data,
+                                 size_t* length) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+
+  v8::Local<v8::Value> buffer = v8impl::V8LocalValueFromJsValue(value);
+
+  if (data != nullptr) {
+    *data = node::Buffer::Data(buffer);
+  }
+  if (length != nullptr) {
+    *length = node::Buffer::Length(buffer);
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_is_arraybuffer(napi_env env, napi_value value, bool* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  *result = val->IsArrayBuffer();
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_arraybuffer(napi_env env,
+                                    size_t byte_length,
+                                    void** data,
+                                    napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::ArrayBuffer> buffer =
+      v8::ArrayBuffer::New(isolate, byte_length);
+
+  // Optionally return a pointer to the buffer's data, to avoid another call to
+  // retrieve it.
+  if (data != nullptr) {
+    *data = buffer->GetContents().Data();
+  }
+
+  *result = v8impl::JsValueFromV8LocalValue(buffer);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_create_external_arraybuffer(napi_env env,
+                                             void* external_data,
+                                             size_t byte_length,
+                                             napi_finalize finalize_cb,
+                                             void* finalize_hint,
+                                             napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, result);
+
+  v8::Isolate* isolate = env->isolate;
+  v8::Local<v8::ArrayBuffer> buffer =
+      v8::ArrayBuffer::New(isolate, external_data, byte_length);
+
+  if (finalize_cb != nullptr) {
+    // Create a self-deleting weak reference that invokes the finalizer
+    // callback.
+    v8impl::Reference::New(env,
+        buffer,
+        0,
+        true,
+        finalize_cb,
+        external_data,
+        finalize_hint);
+  }
+
+  *result = v8impl::JsValueFromV8LocalValue(buffer);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_get_arraybuffer_info(napi_env env,
+                                      napi_value arraybuffer,
+                                      void** data,
+                                      size_t* byte_length) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, arraybuffer);
+
+  v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(arraybuffer);
+  RETURN_STATUS_IF_FALSE(env, value->IsArrayBuffer(), napi_invalid_arg);
+
+  v8::ArrayBuffer::Contents contents =
+      value.As<v8::ArrayBuffer>()->GetContents();
+
+  if (data != nullptr) {
+    *data = contents.Data();
+  }
+
+  if (byte_length != nullptr) {
+    *byte_length = contents.ByteLength();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_is_typedarray(napi_env env, napi_value value, bool* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  *result = val->IsTypedArray();
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_typedarray(napi_env env,
+                                   napi_typedarray_type type,
+                                   size_t length,
+                                   napi_value arraybuffer,
+                                   size_t byte_offset,
+                                   napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, arraybuffer);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(arraybuffer);
+  RETURN_STATUS_IF_FALSE(env, value->IsArrayBuffer(), napi_invalid_arg);
+
+  v8::Local<v8::ArrayBuffer> buffer = value.As<v8::ArrayBuffer>();
+  v8::Local<v8::TypedArray> typedArray;
+
+  switch (type) {
+    case napi_int8_array:
+      CREATE_TYPED_ARRAY(
+          env, Int8Array, 1, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_uint8_array:
+      CREATE_TYPED_ARRAY(
+          env, Uint8Array, 1, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_uint8_clamped_array:
+      CREATE_TYPED_ARRAY(
+          env, Uint8ClampedArray, 1, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_int16_array:
+      CREATE_TYPED_ARRAY(
+          env, Int16Array, 2, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_uint16_array:
+      CREATE_TYPED_ARRAY(
+          env, Uint16Array, 2, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_int32_array:
+      CREATE_TYPED_ARRAY(
+          env, Int32Array, 4, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_uint32_array:
+      CREATE_TYPED_ARRAY(
+          env, Uint32Array, 4, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_float32_array:
+      CREATE_TYPED_ARRAY(
+          env, Float32Array, 4, buffer, byte_offset, length, typedArray);
+      break;
+    case napi_float64_array:
+      CREATE_TYPED_ARRAY(
+          env, Float64Array, 8, buffer, byte_offset, length, typedArray);
+      break;
+    default:
+      return napi_set_last_error(env, napi_invalid_arg);
+  }
+
+  *result = v8impl::JsValueFromV8LocalValue(typedArray);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_get_typedarray_info(napi_env env,
+                                     napi_value typedarray,
+                                     napi_typedarray_type* type,
+                                     size_t* length,
+                                     void** data,
+                                     napi_value* arraybuffer,
+                                     size_t* byte_offset) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, typedarray);
+
+  v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(typedarray);
+  RETURN_STATUS_IF_FALSE(env, value->IsTypedArray(), napi_invalid_arg);
+
+  v8::Local<v8::TypedArray> array = value.As<v8::TypedArray>();
+
+  if (type != nullptr) {
+    if (value->IsInt8Array()) {
+      *type = napi_int8_array;
+    } else if (value->IsUint8Array()) {
+      *type = napi_uint8_array;
+    } else if (value->IsUint8ClampedArray()) {
+      *type = napi_uint8_clamped_array;
+    } else if (value->IsInt16Array()) {
+      *type = napi_int16_array;
+    } else if (value->IsUint16Array()) {
+      *type = napi_uint16_array;
+    } else if (value->IsInt32Array()) {
+      *type = napi_int32_array;
+    } else if (value->IsUint32Array()) {
+      *type = napi_uint32_array;
+    } else if (value->IsFloat32Array()) {
+      *type = napi_float32_array;
+    } else if (value->IsFloat64Array()) {
+      *type = napi_float64_array;
+    }
+  }
+
+  if (length != nullptr) {
+    *length = array->Length();
+  }
+
+  v8::Local<v8::ArrayBuffer> buffer = array->Buffer();
+  if (data != nullptr) {
+    *data = static_cast<uint8_t*>(buffer->GetContents().Data()) +
+            array->ByteOffset();
+  }
+
+  if (arraybuffer != nullptr) {
+    *arraybuffer = v8impl::JsValueFromV8LocalValue(buffer);
+  }
+
+  if (byte_offset != nullptr) {
+    *byte_offset = array->ByteOffset();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_dataview(napi_env env,
+                                 size_t byte_length,
+                                 napi_value arraybuffer,
+                                 size_t byte_offset,
+                                 napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, arraybuffer);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(arraybuffer);
+  RETURN_STATUS_IF_FALSE(env, value->IsArrayBuffer(), napi_invalid_arg);
+
+  v8::Local<v8::ArrayBuffer> buffer = value.As<v8::ArrayBuffer>();
+  if (byte_length + byte_offset > buffer->ByteLength()) {
+    napi_throw_range_error(
+        env,
+        "ERR_NAPI_INVALID_DATAVIEW_ARGS",
+        "byte_offset + byte_length should be less than or "
+        "equal to the size in bytes of the array passed in");
+    return napi_set_last_error(env, napi_generic_failure);
+  }
+  v8::Local<v8::DataView> DataView = v8::DataView::New(buffer, byte_offset,
+                                                       byte_length);
+
+  *result = v8impl::JsValueFromV8LocalValue(DataView);
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_is_dataview(napi_env env, napi_value value, bool* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, value);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> val = v8impl::V8LocalValueFromJsValue(value);
+  *result = val->IsDataView();
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_dataview_info(napi_env env,
+                                   napi_value dataview,
+                                   size_t* byte_length,
+                                   void** data,
+                                   napi_value* arraybuffer,
+                                   size_t* byte_offset) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, dataview);
+
+  v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(dataview);
+  RETURN_STATUS_IF_FALSE(env, value->IsDataView(), napi_invalid_arg);
+
+  v8::Local<v8::DataView> array = value.As<v8::DataView>();
+
+  if (byte_length != nullptr) {
+    *byte_length = array->ByteLength();
+  }
+
+  v8::Local<v8::ArrayBuffer> buffer = array->Buffer();
+  if (data != nullptr) {
+    *data = static_cast<uint8_t*>(buffer->GetContents().Data()) +
+            array->ByteOffset();
+  }
+
+  if (arraybuffer != nullptr) {
+    *arraybuffer = v8impl::JsValueFromV8LocalValue(buffer);
+  }
+
+  if (byte_offset != nullptr) {
+    *byte_offset = array->ByteOffset();
+  }
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_version(napi_env env, uint32_t* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+  *result = NAPI_VERSION;
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_get_node_version(napi_env env,
+                                  const napi_node_version** result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, result);
+  static const napi_node_version version = {
+    NODE_MAJOR_VERSION,
+    NODE_MINOR_VERSION,
+    NODE_PATCH_VERSION,
+    NODE_RELEASE
+  };
+  *result = &version;
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_adjust_external_memory(napi_env env,
+                                        int64_t change_in_bytes,
+                                        int64_t* adjusted_value) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, adjusted_value);
+
+  *adjusted_value = env->isolate->AdjustAmountOfExternalAllocatedMemory(
+      change_in_bytes);
+
+  return napi_clear_last_error(env);
+}
+
+namespace {
+namespace uvimpl {
+
+static napi_status ConvertUVErrorCode(int code) {
+  switch (code) {
+  case 0:
+    return napi_ok;
+  case UV_EINVAL:
+    return napi_invalid_arg;
+  case UV_ECANCELED:
+    return napi_cancelled;
+  }
+
+  return napi_generic_failure;
+}
+
+// Wrapper around uv_work_t which calls user-provided callbacks.
+class Work : public node::AsyncResource {
+ private:
+  explicit Work(napi_env env,
+                v8::Local<v8::Object> async_resource,
+                v8::Local<v8::String> async_resource_name,
+                napi_async_execute_callback execute,
+                napi_async_complete_callback complete = nullptr,
+                void* data = nullptr)
+    : AsyncResource(env->isolate,
+                    async_resource,
+                    *v8::String::Utf8Value(async_resource_name)),
+    _env(env),
+    _data(data),
+    _execute(execute),
+    _complete(complete) {
+    memset(&_request, 0, sizeof(_request));
+    _request.data = this;
+  }
+
+  ~Work() { }
+
+ public:
+  static Work* New(napi_env env,
+                   v8::Local<v8::Object> async_resource,
+                   v8::Local<v8::String> async_resource_name,
+                   napi_async_execute_callback execute,
+                   napi_async_complete_callback complete,
+                   void* data) {
+    return new Work(env, async_resource, async_resource_name,
+                    execute, complete, data);
+  }
+
+  static void Delete(Work* work) {
+    delete work;
+  }
+
+  static void ExecuteCallback(uv_work_t* req) {
+    Work* work = static_cast<Work*>(req->data);
+    work->_execute(work->_env, work->_data);
+  }
+
+  static void CompleteCallback(uv_work_t* req, int status) {
+    Work* work = static_cast<Work*>(req->data);
+
+    if (work->_complete != nullptr) {
+      napi_env env = work->_env;
+
+      // Establish a handle scope here so that every callback doesn't have to.
+      // Also it is needed for the exception-handling below.
+      v8::HandleScope scope(env->isolate);
+      CallbackScope callback_scope(work);
+
+      NAPI_CALL_INTO_MODULE(env,
+          work->_complete(env, ConvertUVErrorCode(status), work->_data),
+          [env] (v8::Local<v8::Value> local_err) {
+            // If there was an unhandled exception in the complete callback,
+            // report it as a fatal exception. (There is no JavaScript on the
+            // callstack that can possibly handle it.)
+            v8impl::trigger_fatal_exception(env, local_err);
+          });
+
+      // Note: Don't access `work` after this point because it was
+      // likely deleted by the complete callback.
+    }
+  }
+
+  uv_work_t* Request() {
+    return &_request;
+  }
+
+ private:
+  napi_env _env;
+  void* _data;
+  uv_work_t _request;
+  napi_async_execute_callback _execute;
+  napi_async_complete_callback _complete;
+};
+
+}  // end of namespace uvimpl
+}  // end of anonymous namespace
+
+#define CALL_UV(env, condition)                                         \
+  do {                                                                  \
+    int result = (condition);                                           \
+    napi_status status = uvimpl::ConvertUVErrorCode(result);            \
+    if (status != napi_ok) {                                            \
+      return napi_set_last_error(env, status, result);                  \
+    }                                                                   \
+  } while (0)
+
+napi_status napi_create_async_work(napi_env env,
+                                   napi_value async_resource,
+                                   napi_value async_resource_name,
+                                   napi_async_execute_callback execute,
+                                   napi_async_complete_callback complete,
+                                   void* data,
+                                   napi_async_work* result) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, execute);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Context> context = env->isolate->GetCurrentContext();
+
+  v8::Local<v8::Object> resource;
+  if (async_resource != nullptr) {
+    CHECK_TO_OBJECT(env, context, resource, async_resource);
+  } else {
+    resource = v8::Object::New(env->isolate);
+  }
+
+  v8::Local<v8::String> resource_name;
+  CHECK_TO_STRING(env, context, resource_name, async_resource_name);
+
+  uvimpl::Work* work =
+      uvimpl::Work::New(env, resource, resource_name,
+                        execute, complete, data);
+
+  *result = reinterpret_cast<napi_async_work>(work);
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_delete_async_work(napi_env env, napi_async_work work) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, work);
+
+  uvimpl::Work::Delete(reinterpret_cast<uvimpl::Work*>(work));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_queue_async_work(napi_env env, napi_async_work work) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, work);
+
+  // Consider: Encapsulate the uv_loop_t into an opaque pointer parameter.
+  // Currently the environment event loop is the same as the UV default loop.
+  // Someday (if node ever supports multiple isolates), it may be better to get
+  // the loop from node::Environment::GetCurrent(env->isolate)->event_loop();
+  uv_loop_t* event_loop = uv_default_loop();
+
+  uvimpl::Work* w = reinterpret_cast<uvimpl::Work*>(work);
+
+  CALL_UV(env, uv_queue_work(event_loop,
+                             w->Request(),
+                             uvimpl::Work::ExecuteCallback,
+                             uvimpl::Work::CompleteCallback));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_cancel_async_work(napi_env env, napi_async_work work) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, work);
+
+  uvimpl::Work* w = reinterpret_cast<uvimpl::Work*>(work);
+
+  CALL_UV(env, uv_cancel(reinterpret_cast<uv_req_t*>(w->Request())));
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_create_promise(napi_env env,
+                                napi_deferred* deferred,
+                                napi_value* promise) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, deferred);
+  CHECK_ARG(env, promise);
+
+  auto maybe = v8::Promise::Resolver::New(env->isolate->GetCurrentContext());
+  CHECK_MAYBE_EMPTY(env, maybe, napi_generic_failure);
+
+  auto v8_resolver = maybe.ToLocalChecked();
+  auto v8_deferred = new v8::Persistent<v8::Value>();
+  v8_deferred->Reset(env->isolate, v8_resolver);
+
+  *deferred = v8impl::JsDeferredFromV8Persistent(v8_deferred);
+  *promise = v8impl::JsValueFromV8LocalValue(v8_resolver->GetPromise());
+  return GET_RETURN_STATUS(env);
+}
+
+napi_status napi_resolve_deferred(napi_env env,
+                                  napi_deferred deferred,
+                                  napi_value resolution) {
+  return v8impl::ConcludeDeferred(env, deferred, resolution, true);
+}
+
+napi_status napi_reject_deferred(napi_env env,
+                                 napi_deferred deferred,
+                                 napi_value resolution) {
+  return v8impl::ConcludeDeferred(env, deferred, resolution, false);
+}
+
+napi_status napi_is_promise(napi_env env,
+                            napi_value promise,
+                            bool* is_promise) {
+  CHECK_ENV(env);
+  CHECK_ARG(env, promise);
+  CHECK_ARG(env, is_promise);
+
+  *is_promise = v8impl::V8LocalValueFromJsValue(promise)->IsPromise();
+
+  return napi_clear_last_error(env);
+}
+
+napi_status napi_run_script(napi_env env,
+                            napi_value script,
+                            napi_value* result) {
+  NAPI_PREAMBLE(env);
+  CHECK_ARG(env, script);
+  CHECK_ARG(env, result);
+
+  v8::Local<v8::Value> v8_script = v8impl::V8LocalValueFromJsValue(script);
+
+  if (!v8_script->IsString()) {
+    return napi_set_last_error(env, napi_string_expected);
+  }
+
+  v8::Local<v8::Context> context = env->isolate->GetCurrentContext();
+
+  auto maybe_script = v8::Script::Compile(context,
+      v8::Local<v8::String>::Cast(v8_script));
+  CHECK_MAYBE_EMPTY(env, maybe_script, napi_generic_failure);
+
+  auto script_result =
+      maybe_script.ToLocalChecked()->Run(context);
+  CHECK_MAYBE_EMPTY(env, script_result, napi_generic_failure);
+
+  *result = v8impl::JsValueFromV8LocalValue(script_result.ToLocalChecked());
+  return GET_RETURN_STATUS(env);
+}