Index: imaps-frontend/node_modules/node-addon-api/napi.h
===================================================================
--- imaps-frontend/node_modules/node-addon-api/napi.h	(revision 0c6b92add4cfaedcb91bcd37b45849f142f7d152)
+++ imaps-frontend/node_modules/node-addon-api/napi.h	(revision 0c6b92add4cfaedcb91bcd37b45849f142f7d152)
@@ -0,0 +1,3201 @@
+#ifndef SRC_NAPI_H_
+#define SRC_NAPI_H_
+
+#ifndef NAPI_HAS_THREADS
+#if !defined(__wasm__) || (defined(__EMSCRIPTEN_PTHREADS__) ||                 \
+                           (defined(__wasi__) && defined(_REENTRANT)))
+#define NAPI_HAS_THREADS 1
+#else
+#define NAPI_HAS_THREADS 0
+#endif
+#endif
+
+#include <node_api.h>
+#include <functional>
+#include <initializer_list>
+#include <memory>
+#if NAPI_HAS_THREADS
+#include <mutex>
+#endif  // NAPI_HAS_THREADS
+#include <string>
+#include <vector>
+
+// VS2015 RTM has bugs with constexpr, so require min of VS2015 Update 3 (known
+// good version)
+#if !defined(_MSC_VER) || _MSC_FULL_VER >= 190024210
+#define NAPI_HAS_CONSTEXPR 1
+#endif
+
+// VS2013 does not support char16_t literal strings, so we'll work around it
+// using wchar_t strings and casting them. This is safe as long as the character
+// sizes are the same.
+#if defined(_MSC_VER) && _MSC_VER <= 1800
+static_assert(sizeof(char16_t) == sizeof(wchar_t),
+              "Size mismatch between char16_t and wchar_t");
+#define NAPI_WIDE_TEXT(x) reinterpret_cast<char16_t*>(L##x)
+#else
+#define NAPI_WIDE_TEXT(x) u##x
+#endif
+
+// If C++ exceptions are not explicitly enabled or disabled, enable them
+// if exceptions were enabled in the compiler settings.
+#if !defined(NAPI_CPP_EXCEPTIONS) && !defined(NAPI_DISABLE_CPP_EXCEPTIONS)
+#if defined(_CPPUNWIND) || defined(__EXCEPTIONS)
+#define NAPI_CPP_EXCEPTIONS
+#else
+#error Exception support not detected. \
+      Define either NAPI_CPP_EXCEPTIONS or NAPI_DISABLE_CPP_EXCEPTIONS.
+#endif
+#endif
+
+// If C++ NAPI_CPP_EXCEPTIONS are enabled, NODE_ADDON_API_ENABLE_MAYBE should
+// not be set
+#if defined(NAPI_CPP_EXCEPTIONS) && defined(NODE_ADDON_API_ENABLE_MAYBE)
+#error NODE_ADDON_API_ENABLE_MAYBE should not be set when \
+    NAPI_CPP_EXCEPTIONS is defined.
+#endif
+
+#ifdef _NOEXCEPT
+#define NAPI_NOEXCEPT _NOEXCEPT
+#else
+#define NAPI_NOEXCEPT noexcept
+#endif
+
+#ifdef NAPI_CPP_EXCEPTIONS
+
+// When C++ exceptions are enabled, Errors are thrown directly. There is no need
+// to return anything after the throw statements. The variadic parameter is an
+// optional return value that is ignored.
+// We need _VOID versions of the macros to avoid warnings resulting from
+// leaving the NAPI_THROW_* `...` argument empty.
+
+#define NAPI_THROW(e, ...) throw e
+#define NAPI_THROW_VOID(e) throw e
+
+#define NAPI_THROW_IF_FAILED(env, status, ...)                                 \
+  if ((status) != napi_ok) throw Napi::Error::New(env);
+
+#define NAPI_THROW_IF_FAILED_VOID(env, status)                                 \
+  if ((status) != napi_ok) throw Napi::Error::New(env);
+
+#else  // NAPI_CPP_EXCEPTIONS
+
+// When C++ exceptions are disabled, Errors are thrown as JavaScript exceptions,
+// which are pending until the callback returns to JS.  The variadic parameter
+// is an optional return value; usually it is an empty result.
+// We need _VOID versions of the macros to avoid warnings resulting from
+// leaving the NAPI_THROW_* `...` argument empty.
+
+#define NAPI_THROW(e, ...)                                                     \
+  do {                                                                         \
+    (e).ThrowAsJavaScriptException();                                          \
+    return __VA_ARGS__;                                                        \
+  } while (0)
+
+#define NAPI_THROW_VOID(e)                                                     \
+  do {                                                                         \
+    (e).ThrowAsJavaScriptException();                                          \
+    return;                                                                    \
+  } while (0)
+
+#define NAPI_THROW_IF_FAILED(env, status, ...)                                 \
+  if ((status) != napi_ok) {                                                   \
+    Napi::Error::New(env).ThrowAsJavaScriptException();                        \
+    return __VA_ARGS__;                                                        \
+  }
+
+#define NAPI_THROW_IF_FAILED_VOID(env, status)                                 \
+  if ((status) != napi_ok) {                                                   \
+    Napi::Error::New(env).ThrowAsJavaScriptException();                        \
+    return;                                                                    \
+  }
+
+#endif  // NAPI_CPP_EXCEPTIONS
+
+#ifdef NODE_ADDON_API_ENABLE_MAYBE
+#define NAPI_MAYBE_THROW_IF_FAILED(env, status, type)                          \
+  NAPI_THROW_IF_FAILED(env, status, Napi::Nothing<type>())
+
+#define NAPI_RETURN_OR_THROW_IF_FAILED(env, status, result, type)              \
+  NAPI_MAYBE_THROW_IF_FAILED(env, status, type);                               \
+  return Napi::Just<type>(result);
+#else
+#define NAPI_MAYBE_THROW_IF_FAILED(env, status, type)                          \
+  NAPI_THROW_IF_FAILED(env, status, type())
+
+#define NAPI_RETURN_OR_THROW_IF_FAILED(env, status, result, type)              \
+  NAPI_MAYBE_THROW_IF_FAILED(env, status, type);                               \
+  return result;
+#endif
+
+#define NAPI_DISALLOW_ASSIGN(CLASS) void operator=(const CLASS&) = delete;
+#define NAPI_DISALLOW_COPY(CLASS) CLASS(const CLASS&) = delete;
+
+#define NAPI_DISALLOW_ASSIGN_COPY(CLASS)                                       \
+  NAPI_DISALLOW_ASSIGN(CLASS)                                                  \
+  NAPI_DISALLOW_COPY(CLASS)
+
+#define NAPI_CHECK(condition, location, message)                               \
+  do {                                                                         \
+    if (!(condition)) {                                                        \
+      Napi::Error::Fatal((location), (message));                               \
+    }                                                                          \
+  } while (0)
+
+#define NAPI_FATAL_IF_FAILED(status, location, message)                        \
+  NAPI_CHECK((status) == napi_ok, location, message)
+
+////////////////////////////////////////////////////////////////////////////////
+/// Node-API C++ Wrapper Classes
+///
+/// These classes wrap the "Node-API" ABI-stable C APIs for Node.js, providing a
+/// C++ object model and C++ exception-handling semantics with low overhead.
+/// The wrappers are all header-only so that they do not affect the ABI.
+////////////////////////////////////////////////////////////////////////////////
+namespace Napi {
+
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+// NAPI_CPP_CUSTOM_NAMESPACE can be #define'd per-addon to avoid symbol
+// conflicts between different instances of node-addon-api
+
+// First dummy definition of the namespace to make sure that Napi::(name) still
+// refers to the right things inside this file.
+namespace NAPI_CPP_CUSTOM_NAMESPACE {}
+using namespace NAPI_CPP_CUSTOM_NAMESPACE;
+
+namespace NAPI_CPP_CUSTOM_NAMESPACE {
+#endif
+
+// Forward declarations
+class Env;
+class Value;
+class Boolean;
+class Number;
+#if NAPI_VERSION > 5
+class BigInt;
+#endif  // NAPI_VERSION > 5
+#if (NAPI_VERSION > 4)
+class Date;
+#endif
+class String;
+class Object;
+class Array;
+class ArrayBuffer;
+class Function;
+class Error;
+class PropertyDescriptor;
+class CallbackInfo;
+class TypedArray;
+template <typename T>
+class TypedArrayOf;
+
+using Int8Array =
+    TypedArrayOf<int8_t>;  ///< Typed-array of signed 8-bit integers
+using Uint8Array =
+    TypedArrayOf<uint8_t>;  ///< Typed-array of unsigned 8-bit integers
+using Int16Array =
+    TypedArrayOf<int16_t>;  ///< Typed-array of signed 16-bit integers
+using Uint16Array =
+    TypedArrayOf<uint16_t>;  ///< Typed-array of unsigned 16-bit integers
+using Int32Array =
+    TypedArrayOf<int32_t>;  ///< Typed-array of signed 32-bit integers
+using Uint32Array =
+    TypedArrayOf<uint32_t>;  ///< Typed-array of unsigned 32-bit integers
+using Float32Array =
+    TypedArrayOf<float>;  ///< Typed-array of 32-bit floating-point values
+using Float64Array =
+    TypedArrayOf<double>;  ///< Typed-array of 64-bit floating-point values
+#if NAPI_VERSION > 5
+using BigInt64Array =
+    TypedArrayOf<int64_t>;  ///< Typed array of signed 64-bit integers
+using BigUint64Array =
+    TypedArrayOf<uint64_t>;  ///< Typed array of unsigned 64-bit integers
+#endif                       // NAPI_VERSION > 5
+
+/// Defines the signature of a Node-API C++ module's registration callback
+/// (init) function.
+using ModuleRegisterCallback = Object (*)(Env env, Object exports);
+
+class MemoryManagement;
+
+/// A simple Maybe type, representing an object which may or may not have a
+/// value.
+///
+/// If an API method returns a Maybe<>, the API method can potentially fail
+/// either because an exception is thrown, or because an exception is pending,
+/// e.g. because a previous API call threw an exception that hasn't been
+/// caught yet. In that case, a "Nothing" value is returned.
+template <class T>
+class Maybe {
+ public:
+  bool IsNothing() const;
+  bool IsJust() const;
+
+  /// Short-hand for Unwrap(), which doesn't return a value. Could be used
+  /// where the actual value of the Maybe is not needed like Object::Set.
+  /// If this Maybe is nothing (empty), node-addon-api will crash the
+  /// process.
+  void Check() const;
+
+  /// Return the value of type T contained in the Maybe. If this Maybe is
+  /// nothing (empty), node-addon-api will crash the process.
+  T Unwrap() const;
+
+  /// Return the value of type T contained in the Maybe, or using a default
+  /// value if this Maybe is nothing (empty).
+  T UnwrapOr(const T& default_value) const;
+
+  /// Converts this Maybe to a value of type T in the out. If this Maybe is
+  /// nothing (empty), `false` is returned and `out` is left untouched.
+  bool UnwrapTo(T* out) const;
+
+  bool operator==(const Maybe& other) const;
+  bool operator!=(const Maybe& other) const;
+
+ private:
+  Maybe();
+  explicit Maybe(const T& t);
+
+  bool _has_value;
+  T _value;
+
+  template <class U>
+  friend Maybe<U> Nothing();
+  template <class U>
+  friend Maybe<U> Just(const U& u);
+};
+
+template <class T>
+inline Maybe<T> Nothing();
+
+template <class T>
+inline Maybe<T> Just(const T& t);
+
+#if defined(NODE_ADDON_API_ENABLE_MAYBE)
+template <typename T>
+using MaybeOrValue = Maybe<T>;
+#else
+template <typename T>
+using MaybeOrValue = T;
+#endif
+
+/// Environment for Node-API values and operations.
+///
+/// All Node-API values and operations must be associated with an environment.
+/// An environment instance is always provided to callback functions; that
+/// environment must then be used for any creation of Node-API values or other
+/// Node-API operations within the callback. (Many methods infer the
+/// environment from the `this` instance that the method is called on.)
+///
+/// In the future, multiple environments per process may be supported,
+/// although current implementations only support one environment per process.
+///
+/// In the V8 JavaScript engine, a Node-API environment approximately
+/// corresponds to an Isolate.
+class Env {
+ private:
+  napi_env _env;
+#if NAPI_VERSION > 5
+  template <typename T>
+  static void DefaultFini(Env, T* data);
+  template <typename DataType, typename HintType>
+  static void DefaultFiniWithHint(Env, DataType* data, HintType* hint);
+#endif  // NAPI_VERSION > 5
+ public:
+  Env(napi_env env);
+
+  operator napi_env() const;
+
+  Object Global() const;
+  Value Undefined() const;
+  Value Null() const;
+
+  bool IsExceptionPending() const;
+  Error GetAndClearPendingException() const;
+
+  MaybeOrValue<Value> RunScript(const char* utf8script) const;
+  MaybeOrValue<Value> RunScript(const std::string& utf8script) const;
+  MaybeOrValue<Value> RunScript(String script) const;
+
+#if NAPI_VERSION > 2
+  template <typename Hook, typename Arg = void>
+  class CleanupHook;
+
+  template <typename Hook>
+  CleanupHook<Hook> AddCleanupHook(Hook hook);
+
+  template <typename Hook, typename Arg>
+  CleanupHook<Hook, Arg> AddCleanupHook(Hook hook, Arg* arg);
+#endif  // NAPI_VERSION > 2
+
+#if NAPI_VERSION > 5
+  template <typename T>
+  T* GetInstanceData() const;
+
+  template <typename T>
+  using Finalizer = void (*)(Env, T*);
+  template <typename T, Finalizer<T> fini = Env::DefaultFini<T>>
+  void SetInstanceData(T* data) const;
+
+  template <typename DataType, typename HintType>
+  using FinalizerWithHint = void (*)(Env, DataType*, HintType*);
+  template <typename DataType,
+            typename HintType,
+            FinalizerWithHint<DataType, HintType> fini =
+                Env::DefaultFiniWithHint<DataType, HintType>>
+  void SetInstanceData(DataType* data, HintType* hint) const;
+#endif  // NAPI_VERSION > 5
+
+#if NAPI_VERSION > 2
+  template <typename Hook, typename Arg>
+  class CleanupHook {
+   public:
+    CleanupHook();
+    CleanupHook(Env env, Hook hook, Arg* arg);
+    CleanupHook(Env env, Hook hook);
+    bool Remove(Env env);
+    bool IsEmpty() const;
+
+   private:
+    static inline void Wrapper(void* data) NAPI_NOEXCEPT;
+    static inline void WrapperWithArg(void* data) NAPI_NOEXCEPT;
+
+    void (*wrapper)(void* arg);
+    struct CleanupData {
+      Hook hook;
+      Arg* arg;
+    } * data;
+  };
+#endif  // NAPI_VERSION > 2
+
+#if NAPI_VERSION > 8
+  const char* GetModuleFileName() const;
+#endif  // NAPI_VERSION > 8
+};
+
+/// A JavaScript value of unknown type.
+///
+/// For type-specific operations, convert to one of the Value subclasses using a
+/// `To*` or `As()` method. The `To*` methods do type coercion; the `As()`
+/// method does not.
+///
+///     Napi::Value value = ...
+///     if (!value.IsString()) throw Napi::TypeError::New(env, "Invalid
+///     arg..."); Napi::String str = value.As<Napi::String>(); // Cast to a
+///     string value
+///
+///     Napi::Value anotherValue = ...
+///     bool isTruthy = anotherValue.ToBoolean(); // Coerce to a boolean value
+class Value {
+ public:
+  Value();  ///< Creates a new _empty_ Value instance.
+  Value(napi_env env,
+        napi_value value);  ///< Wraps a Node-API value primitive.
+
+  /// Creates a JS value from a C++ primitive.
+  ///
+  /// `value` may be any of:
+  /// - bool
+  /// - Any integer type
+  /// - Any floating point type
+  /// - const char* (encoded using UTF-8, null-terminated)
+  /// - const char16_t* (encoded using UTF-16-LE, null-terminated)
+  /// - std::string (encoded using UTF-8)
+  /// - std::u16string
+  /// - napi::Value
+  /// - napi_value
+  template <typename T>
+  static Value From(napi_env env, const T& value);
+
+  /// Converts to a Node-API value primitive.
+  ///
+  /// If the instance is _empty_, this returns `nullptr`.
+  operator napi_value() const;
+
+  /// Tests if this value strictly equals another value.
+  bool operator==(const Value& other) const;
+
+  /// Tests if this value does not strictly equal another value.
+  bool operator!=(const Value& other) const;
+
+  /// Tests if this value strictly equals another value.
+  bool StrictEquals(const Value& other) const;
+
+  /// Gets the environment the value is associated with.
+  Napi::Env Env() const;
+
+  /// Checks if the value is empty (uninitialized).
+  ///
+  /// An empty value is invalid, and most attempts to perform an operation on an
+  /// empty value will result in an exception. Note an empty value is distinct
+  /// from JavaScript `null` or `undefined`, which are valid values.
+  ///
+  /// When C++ exceptions are disabled at compile time, a method with a `Value`
+  /// return type may return an empty value to indicate a pending exception. So
+  /// when not using C++ exceptions, callers should check whether the value is
+  /// empty before attempting to use it.
+  bool IsEmpty() const;
+
+  napi_valuetype Type() const;  ///< Gets the type of the value.
+
+  bool IsUndefined()
+      const;            ///< Tests if a value is an undefined JavaScript value.
+  bool IsNull() const;  ///< Tests if a value is a null JavaScript value.
+  bool IsBoolean() const;  ///< Tests if a value is a JavaScript boolean.
+  bool IsNumber() const;   ///< Tests if a value is a JavaScript number.
+#if NAPI_VERSION > 5
+  bool IsBigInt() const;  ///< Tests if a value is a JavaScript bigint.
+#endif                    // NAPI_VERSION > 5
+#if (NAPI_VERSION > 4)
+  bool IsDate() const;  ///< Tests if a value is a JavaScript date.
+#endif
+  bool IsString() const;  ///< Tests if a value is a JavaScript string.
+  bool IsSymbol() const;  ///< Tests if a value is a JavaScript symbol.
+  bool IsArray() const;   ///< Tests if a value is a JavaScript array.
+  bool IsArrayBuffer()
+      const;  ///< Tests if a value is a JavaScript array buffer.
+  bool IsTypedArray() const;  ///< Tests if a value is a JavaScript typed array.
+  bool IsObject() const;      ///< Tests if a value is a JavaScript object.
+  bool IsFunction() const;    ///< Tests if a value is a JavaScript function.
+  bool IsPromise() const;     ///< Tests if a value is a JavaScript promise.
+  bool IsDataView() const;    ///< Tests if a value is a JavaScript data view.
+  bool IsBuffer() const;      ///< Tests if a value is a Node buffer.
+  bool IsExternal() const;  ///< Tests if a value is a pointer to external data.
+
+  /// Casts to another type of `Napi::Value`, when the actual type is known or
+  /// assumed.
+  ///
+  /// This conversion does NOT coerce the type. Calling any methods
+  /// inappropriate for the actual value type will throw `Napi::Error`.
+  ///
+  /// If `NODE_ADDON_API_ENABLE_TYPE_CHECK_ON_AS` is defined, this method
+  /// asserts that the actual type is the expected type.
+  template <typename T>
+  T As() const;
+
+  MaybeOrValue<Boolean> ToBoolean()
+      const;  ///< Coerces a value to a JavaScript boolean.
+  MaybeOrValue<Number> ToNumber()
+      const;  ///< Coerces a value to a JavaScript number.
+  MaybeOrValue<String> ToString()
+      const;  ///< Coerces a value to a JavaScript string.
+  MaybeOrValue<Object> ToObject()
+      const;  ///< Coerces a value to a JavaScript object.
+
+ protected:
+  /// !cond INTERNAL
+  napi_env _env;
+  napi_value _value;
+  /// !endcond
+};
+
+/// A JavaScript boolean value.
+class Boolean : public Value {
+ public:
+  static Boolean New(napi_env env,  ///< Node-API environment
+                     bool value     ///< Boolean value
+  );
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Boolean();  ///< Creates a new _empty_ Boolean instance.
+  Boolean(napi_env env,
+          napi_value value);  ///< Wraps a Node-API value primitive.
+
+  operator bool() const;  ///< Converts a Boolean value to a boolean primitive.
+  bool Value() const;     ///< Converts a Boolean value to a boolean primitive.
+};
+
+/// A JavaScript number value.
+class Number : public Value {
+ public:
+  static Number New(napi_env env,  ///< Node-API environment
+                    double value   ///< Number value
+  );
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Number();  ///< Creates a new _empty_ Number instance.
+  Number(napi_env env,
+         napi_value value);  ///< Wraps a Node-API value primitive.
+
+  operator int32_t()
+      const;  ///< Converts a Number value to a 32-bit signed integer value.
+  operator uint32_t()
+      const;  ///< Converts a Number value to a 32-bit unsigned integer value.
+  operator int64_t()
+      const;  ///< Converts a Number value to a 64-bit signed integer value.
+  operator float()
+      const;  ///< Converts a Number value to a 32-bit floating-point value.
+  operator double()
+      const;  ///< Converts a Number value to a 64-bit floating-point value.
+
+  int32_t Int32Value()
+      const;  ///< Converts a Number value to a 32-bit signed integer value.
+  uint32_t Uint32Value()
+      const;  ///< Converts a Number value to a 32-bit unsigned integer value.
+  int64_t Int64Value()
+      const;  ///< Converts a Number value to a 64-bit signed integer value.
+  float FloatValue()
+      const;  ///< Converts a Number value to a 32-bit floating-point value.
+  double DoubleValue()
+      const;  ///< Converts a Number value to a 64-bit floating-point value.
+};
+
+#if NAPI_VERSION > 5
+/// A JavaScript bigint value.
+class BigInt : public Value {
+ public:
+  static BigInt New(napi_env env,  ///< Node-API environment
+                    int64_t value  ///< Number value
+  );
+  static BigInt New(napi_env env,   ///< Node-API environment
+                    uint64_t value  ///< Number value
+  );
+
+  /// Creates a new BigInt object using a specified sign bit and a
+  /// specified list of digits/words.
+  /// The resulting number is calculated as:
+  /// (-1)^sign_bit * (words[0] * (2^64)^0 + words[1] * (2^64)^1 + ...)
+  static BigInt New(napi_env env,          ///< Node-API environment
+                    int sign_bit,          ///< Sign bit. 1 if negative.
+                    size_t word_count,     ///< Number of words in array
+                    const uint64_t* words  ///< Array of words
+  );
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  BigInt();  ///< Creates a new _empty_ BigInt instance.
+  BigInt(napi_env env,
+         napi_value value);  ///< Wraps a Node-API value primitive.
+
+  int64_t Int64Value(bool* lossless)
+      const;  ///< Converts a BigInt value to a 64-bit signed integer value.
+  uint64_t Uint64Value(bool* lossless)
+      const;  ///< Converts a BigInt value to a 64-bit unsigned integer value.
+
+  size_t WordCount() const;  ///< The number of 64-bit words needed to store
+                             ///< the result of ToWords().
+
+  /// Writes the contents of this BigInt to a specified memory location.
+  /// `sign_bit` must be provided and will be set to 1 if this BigInt is
+  /// negative.
+  /// `*word_count` has to be initialized to the length of the `words` array.
+  /// Upon return, it will be set to the actual number of words that would
+  /// be needed to store this BigInt (i.e. the return value of `WordCount()`).
+  void ToWords(int* sign_bit, size_t* word_count, uint64_t* words);
+};
+#endif  // NAPI_VERSION > 5
+
+#if (NAPI_VERSION > 4)
+/// A JavaScript date value.
+class Date : public Value {
+ public:
+  /// Creates a new Date value from a double primitive.
+  static Date New(napi_env env,  ///< Node-API environment
+                  double value   ///< Number value
+  );
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Date();  ///< Creates a new _empty_ Date instance.
+  Date(napi_env env, napi_value value);  ///< Wraps a Node-API value primitive.
+  operator double() const;  ///< Converts a Date value to double primitive
+
+  double ValueOf() const;  ///< Converts a Date value to a double primitive.
+};
+#endif
+
+/// A JavaScript string or symbol value (that can be used as a property name).
+class Name : public Value {
+ public:
+  static void CheckCast(napi_env env, napi_value value);
+
+  Name();  ///< Creates a new _empty_ Name instance.
+  Name(napi_env env,
+       napi_value value);  ///< Wraps a Node-API value primitive.
+};
+
+/// A JavaScript string value.
+class String : public Name {
+ public:
+  /// Creates a new String value from a UTF-8 encoded C++ string.
+  static String New(napi_env env,             ///< Node-API environment
+                    const std::string& value  ///< UTF-8 encoded C++ string
+  );
+
+  /// Creates a new String value from a UTF-16 encoded C++ string.
+  static String New(napi_env env,                ///< Node-API environment
+                    const std::u16string& value  ///< UTF-16 encoded C++ string
+  );
+
+  /// Creates a new String value from a UTF-8 encoded C string.
+  static String New(
+      napi_env env,      ///< Node-API environment
+      const char* value  ///< UTF-8 encoded null-terminated C string
+  );
+
+  /// Creates a new String value from a UTF-16 encoded C string.
+  static String New(
+      napi_env env,          ///< Node-API environment
+      const char16_t* value  ///< UTF-16 encoded null-terminated C string
+  );
+
+  /// Creates a new String value from a UTF-8 encoded C string with specified
+  /// length.
+  static String New(napi_env env,       ///< Node-API environment
+                    const char* value,  ///< UTF-8 encoded C string (not
+                                        ///< necessarily null-terminated)
+                    size_t length       ///< length of the string in bytes
+  );
+
+  /// Creates a new String value from a UTF-16 encoded C string with specified
+  /// length.
+  static String New(
+      napi_env env,           ///< Node-API environment
+      const char16_t* value,  ///< UTF-16 encoded C string (not necessarily
+                              ///< null-terminated)
+      size_t length           ///< Length of the string in 2-byte code units
+  );
+
+  /// Creates a new String based on the original object's type.
+  ///
+  /// `value` may be any of:
+  /// - const char* (encoded using UTF-8, null-terminated)
+  /// - const char16_t* (encoded using UTF-16-LE, null-terminated)
+  /// - std::string (encoded using UTF-8)
+  /// - std::u16string
+  template <typename T>
+  static String From(napi_env env, const T& value);
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  String();  ///< Creates a new _empty_ String instance.
+  String(napi_env env,
+         napi_value value);  ///< Wraps a Node-API value primitive.
+
+  operator std::string()
+      const;  ///< Converts a String value to a UTF-8 encoded C++ string.
+  operator std::u16string()
+      const;  ///< Converts a String value to a UTF-16 encoded C++ string.
+  std::string Utf8Value()
+      const;  ///< Converts a String value to a UTF-8 encoded C++ string.
+  std::u16string Utf16Value()
+      const;  ///< Converts a String value to a UTF-16 encoded C++ string.
+};
+
+/// A JavaScript symbol value.
+class Symbol : public Name {
+ public:
+  /// Creates a new Symbol value with an optional description.
+  static Symbol New(
+      napi_env env,  ///< Node-API environment
+      const char* description =
+          nullptr  ///< Optional UTF-8 encoded null-terminated C string
+                   ///  describing the symbol
+  );
+
+  /// Creates a new Symbol value with a description.
+  static Symbol New(
+      napi_env env,  ///< Node-API environment
+      const std::string&
+          description  ///< UTF-8 encoded C++ string describing the symbol
+  );
+
+  /// Creates a new Symbol value with a description.
+  static Symbol New(napi_env env,       ///< Node-API environment
+                    String description  ///< String value describing the symbol
+  );
+
+  /// Creates a new Symbol value with a description.
+  static Symbol New(
+      napi_env env,           ///< Node-API environment
+      napi_value description  ///< String value describing the symbol
+  );
+
+  /// Get a public Symbol (e.g. Symbol.iterator).
+  static MaybeOrValue<Symbol> WellKnown(napi_env, const std::string& name);
+
+  // Create a symbol in the global registry, UTF-8 Encoded cpp string
+  static MaybeOrValue<Symbol> For(napi_env env, const std::string& description);
+
+  // Create a symbol in the global registry, C style string (null terminated)
+  static MaybeOrValue<Symbol> For(napi_env env, const char* description);
+
+  // Create a symbol in the global registry, String value describing the symbol
+  static MaybeOrValue<Symbol> For(napi_env env, String description);
+
+  // Create a symbol in the global registry, napi_value describing the symbol
+  static MaybeOrValue<Symbol> For(napi_env env, napi_value description);
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Symbol();  ///< Creates a new _empty_ Symbol instance.
+  Symbol(napi_env env,
+         napi_value value);  ///< Wraps a Node-API value primitive.
+};
+
+class TypeTaggable : public Value {
+ public:
+#if NAPI_VERSION >= 8
+  void TypeTag(const napi_type_tag* type_tag) const;
+  bool CheckTypeTag(const napi_type_tag* type_tag) const;
+#endif  // NAPI_VERSION >= 8
+ protected:
+  TypeTaggable();
+  TypeTaggable(napi_env env, napi_value value);
+};
+
+/// A JavaScript object value.
+class Object : public TypeTaggable {
+ public:
+  /// Enables property and element assignments using indexing syntax.
+  ///
+  /// This is a convenient helper to get and set object properties. As
+  /// getting and setting object properties may throw with JavaScript
+  /// exceptions, it is notable that these operations may fail.
+  /// When NODE_ADDON_API_ENABLE_MAYBE is defined, the process will abort
+  /// on JavaScript exceptions.
+  ///
+  /// Example:
+  ///
+  ///     Napi::Value propertyValue = object1['A'];
+  ///     object2['A'] = propertyValue;
+  ///     Napi::Value elementValue = array[0];
+  ///     array[1] = elementValue;
+  template <typename Key>
+  class PropertyLValue {
+   public:
+    /// Converts an L-value to a value.
+    operator Value() const;
+
+    /// Assigns a value to the property. The type of value can be
+    /// anything supported by `Object::Set`.
+    template <typename ValueType>
+    PropertyLValue& operator=(ValueType value);
+
+   private:
+    PropertyLValue() = delete;
+    PropertyLValue(Object object, Key key);
+    napi_env _env;
+    napi_value _object;
+    Key _key;
+
+    friend class Napi::Object;
+  };
+
+  /// Creates a new Object value.
+  static Object New(napi_env env  ///< Node-API environment
+  );
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Object();  ///< Creates a new _empty_ Object instance.
+  Object(napi_env env,
+         napi_value value);  ///< Wraps a Node-API value primitive.
+
+  /// Gets or sets a named property.
+  PropertyLValue<std::string> operator[](
+      const char* utf8name  ///< UTF-8 encoded null-terminated property name
+  );
+
+  /// Gets or sets a named property.
+  PropertyLValue<std::string> operator[](
+      const std::string& utf8name  ///< UTF-8 encoded property name
+  );
+
+  /// Gets or sets an indexed property or array element.
+  PropertyLValue<uint32_t> operator[](
+      uint32_t index  /// Property / element index
+  );
+
+  /// Gets or sets an indexed property or array element.
+  PropertyLValue<Value> operator[](Value index  /// Property / element index
+  ) const;
+
+  /// Gets a named property.
+  MaybeOrValue<Value> operator[](
+      const char* utf8name  ///< UTF-8 encoded null-terminated property name
+  ) const;
+
+  /// Gets a named property.
+  MaybeOrValue<Value> operator[](
+      const std::string& utf8name  ///< UTF-8 encoded property name
+  ) const;
+
+  /// Gets an indexed property or array element.
+  MaybeOrValue<Value> operator[](uint32_t index  ///< Property / element index
+  ) const;
+
+  /// Checks whether a property is present.
+  MaybeOrValue<bool> Has(napi_value key  ///< Property key primitive
+  ) const;
+
+  /// Checks whether a property is present.
+  MaybeOrValue<bool> Has(Value key  ///< Property key
+  ) const;
+
+  /// Checks whether a named property is present.
+  MaybeOrValue<bool> Has(
+      const char* utf8name  ///< UTF-8 encoded null-terminated property name
+  ) const;
+
+  /// Checks whether a named property is present.
+  MaybeOrValue<bool> Has(
+      const std::string& utf8name  ///< UTF-8 encoded property name
+  ) const;
+
+  /// Checks whether a own property is present.
+  MaybeOrValue<bool> HasOwnProperty(napi_value key  ///< Property key primitive
+  ) const;
+
+  /// Checks whether a own property is present.
+  MaybeOrValue<bool> HasOwnProperty(Value key  ///< Property key
+  ) const;
+
+  /// Checks whether a own property is present.
+  MaybeOrValue<bool> HasOwnProperty(
+      const char* utf8name  ///< UTF-8 encoded null-terminated property name
+  ) const;
+
+  /// Checks whether a own property is present.
+  MaybeOrValue<bool> HasOwnProperty(
+      const std::string& utf8name  ///< UTF-8 encoded property name
+  ) const;
+
+  /// Gets a property.
+  MaybeOrValue<Value> Get(napi_value key  ///< Property key primitive
+  ) const;
+
+  /// Gets a property.
+  MaybeOrValue<Value> Get(Value key  ///< Property key
+  ) const;
+
+  /// Gets a named property.
+  MaybeOrValue<Value> Get(
+      const char* utf8name  ///< UTF-8 encoded null-terminated property name
+  ) const;
+
+  /// Gets a named property.
+  MaybeOrValue<Value> Get(
+      const std::string& utf8name  ///< UTF-8 encoded property name
+  ) const;
+
+  /// Sets a property.
+  template <typename ValueType>
+  MaybeOrValue<bool> Set(napi_value key,         ///< Property key primitive
+                         const ValueType& value  ///< Property value primitive
+  ) const;
+
+  /// Sets a property.
+  template <typename ValueType>
+  MaybeOrValue<bool> Set(Value key,              ///< Property key
+                         const ValueType& value  ///< Property value
+  ) const;
+
+  /// Sets a named property.
+  template <typename ValueType>
+  MaybeOrValue<bool> Set(
+      const char* utf8name,  ///< UTF-8 encoded null-terminated property name
+      const ValueType& value) const;
+
+  /// Sets a named property.
+  template <typename ValueType>
+  MaybeOrValue<bool> Set(
+      const std::string& utf8name,  ///< UTF-8 encoded property name
+      const ValueType& value        ///< Property value primitive
+  ) const;
+
+  /// Delete property.
+  MaybeOrValue<bool> Delete(napi_value key  ///< Property key primitive
+  ) const;
+
+  /// Delete property.
+  MaybeOrValue<bool> Delete(Value key  ///< Property key
+  ) const;
+
+  /// Delete property.
+  MaybeOrValue<bool> Delete(
+      const char* utf8name  ///< UTF-8 encoded null-terminated property name
+  ) const;
+
+  /// Delete property.
+  MaybeOrValue<bool> Delete(
+      const std::string& utf8name  ///< UTF-8 encoded property name
+  ) const;
+
+  /// Checks whether an indexed property is present.
+  MaybeOrValue<bool> Has(uint32_t index  ///< Property / element index
+  ) const;
+
+  /// Gets an indexed property or array element.
+  MaybeOrValue<Value> Get(uint32_t index  ///< Property / element index
+  ) const;
+
+  /// Sets an indexed property or array element.
+  template <typename ValueType>
+  MaybeOrValue<bool> Set(uint32_t index,         ///< Property / element index
+                         const ValueType& value  ///< Property value primitive
+  ) const;
+
+  /// Deletes an indexed property or array element.
+  MaybeOrValue<bool> Delete(uint32_t index  ///< Property / element index
+  ) const;
+
+  /// This operation can fail in case of Proxy.[[OwnPropertyKeys]] and
+  /// Proxy.[[GetOwnProperty]] calling into JavaScript. See:
+  /// -
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-ownpropertykeys
+  /// -
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-getownproperty-p
+  MaybeOrValue<Array> GetPropertyNames() const;  ///< Get all property names
+
+  /// Defines a property on the object.
+  ///
+  /// This operation can fail in case of Proxy.[[DefineOwnProperty]] calling
+  /// into JavaScript. See
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc
+  MaybeOrValue<bool> DefineProperty(
+      const PropertyDescriptor&
+          property  ///< Descriptor for the property to be defined
+  ) const;
+
+  /// Defines properties on the object.
+  ///
+  /// This operation can fail in case of Proxy.[[DefineOwnProperty]] calling
+  /// into JavaScript. See
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc
+  MaybeOrValue<bool> DefineProperties(
+      const std::initializer_list<PropertyDescriptor>& properties
+      ///< List of descriptors for the properties to be defined
+  ) const;
+
+  /// Defines properties on the object.
+  ///
+  /// This operation can fail in case of Proxy.[[DefineOwnProperty]] calling
+  /// into JavaScript. See
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-defineownproperty-p-desc
+  MaybeOrValue<bool> DefineProperties(
+      const std::vector<PropertyDescriptor>& properties
+      ///< Vector of descriptors for the properties to be defined
+  ) const;
+
+  /// Checks if an object is an instance created by a constructor function.
+  ///
+  /// This is equivalent to the JavaScript `instanceof` operator.
+  ///
+  /// This operation can fail in case of Proxy.[[GetPrototypeOf]] calling into
+  /// JavaScript.
+  /// See
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-getprototypeof
+  MaybeOrValue<bool> InstanceOf(
+      const Function& constructor  ///< Constructor function
+  ) const;
+
+  template <typename Finalizer, typename T>
+  inline void AddFinalizer(Finalizer finalizeCallback, T* data) const;
+
+  template <typename Finalizer, typename T, typename Hint>
+  inline void AddFinalizer(Finalizer finalizeCallback,
+                           T* data,
+                           Hint* finalizeHint) const;
+
+#ifdef NAPI_CPP_EXCEPTIONS
+  class const_iterator;
+
+  inline const_iterator begin() const;
+
+  inline const_iterator end() const;
+
+  class iterator;
+
+  inline iterator begin();
+
+  inline iterator end();
+#endif  // NAPI_CPP_EXCEPTIONS
+
+#if NAPI_VERSION >= 8
+  /// This operation can fail in case of Proxy.[[GetPrototypeOf]] calling into
+  /// JavaScript.
+  /// See
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-getprototypeof
+  MaybeOrValue<bool> Freeze() const;
+  /// This operation can fail in case of Proxy.[[GetPrototypeOf]] calling into
+  /// JavaScript.
+  /// See
+  /// https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-getprototypeof
+  MaybeOrValue<bool> Seal() const;
+#endif  // NAPI_VERSION >= 8
+};
+
+template <typename T>
+class External : public TypeTaggable {
+ public:
+  static External New(napi_env env, T* data);
+
+  // Finalizer must implement `void operator()(Env env, T* data)`.
+  template <typename Finalizer>
+  static External New(napi_env env, T* data, Finalizer finalizeCallback);
+  // Finalizer must implement `void operator()(Env env, T* data, Hint* hint)`.
+  template <typename Finalizer, typename Hint>
+  static External New(napi_env env,
+                      T* data,
+                      Finalizer finalizeCallback,
+                      Hint* finalizeHint);
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  External();
+  External(napi_env env, napi_value value);
+
+  T* Data() const;
+};
+
+class Array : public Object {
+ public:
+  static Array New(napi_env env);
+  static Array New(napi_env env, size_t length);
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Array();
+  Array(napi_env env, napi_value value);
+
+  uint32_t Length() const;
+};
+
+#ifdef NAPI_CPP_EXCEPTIONS
+class Object::const_iterator {
+ private:
+  enum class Type { BEGIN, END };
+
+  inline const_iterator(const Object* object, const Type type);
+
+ public:
+  inline const_iterator& operator++();
+
+  inline bool operator==(const const_iterator& other) const;
+
+  inline bool operator!=(const const_iterator& other) const;
+
+  inline const std::pair<Value, Object::PropertyLValue<Value>> operator*()
+      const;
+
+ private:
+  const Napi::Object* _object;
+  Array _keys;
+  uint32_t _index;
+
+  friend class Object;
+};
+
+class Object::iterator {
+ private:
+  enum class Type { BEGIN, END };
+
+  inline iterator(Object* object, const Type type);
+
+ public:
+  inline iterator& operator++();
+
+  inline bool operator==(const iterator& other) const;
+
+  inline bool operator!=(const iterator& other) const;
+
+  inline std::pair<Value, Object::PropertyLValue<Value>> operator*();
+
+ private:
+  Napi::Object* _object;
+  Array _keys;
+  uint32_t _index;
+
+  friend class Object;
+};
+#endif  // NAPI_CPP_EXCEPTIONS
+
+/// A JavaScript array buffer value.
+class ArrayBuffer : public Object {
+ public:
+  /// Creates a new ArrayBuffer instance over a new automatically-allocated
+  /// buffer.
+  static ArrayBuffer New(
+      napi_env env,      ///< Node-API environment
+      size_t byteLength  ///< Length of the buffer to be allocated, in bytes
+  );
+
+#ifndef NODE_API_NO_EXTERNAL_BUFFERS_ALLOWED
+  /// Creates a new ArrayBuffer instance, using an external buffer with
+  /// specified byte length.
+  static ArrayBuffer New(
+      napi_env env,        ///< Node-API environment
+      void* externalData,  ///< Pointer to the external buffer to be used by
+                           ///< the array
+      size_t byteLength    ///< Length of the external buffer to be used by the
+                           ///< array, in bytes
+  );
+
+  /// Creates a new ArrayBuffer instance, using an external buffer with
+  /// specified byte length.
+  template <typename Finalizer>
+  static ArrayBuffer New(
+      napi_env env,        ///< Node-API environment
+      void* externalData,  ///< Pointer to the external buffer to be used by
+                           ///< the array
+      size_t byteLength,   ///< Length of the external buffer to be used by the
+                           ///< array,
+                           ///  in bytes
+      Finalizer finalizeCallback  ///< Function to be called when the array
+                                  ///< buffer is destroyed;
+                                  ///  must implement `void operator()(Env env,
+                                  ///  void* externalData)`
+  );
+
+  /// Creates a new ArrayBuffer instance, using an external buffer with
+  /// specified byte length.
+  template <typename Finalizer, typename Hint>
+  static ArrayBuffer New(
+      napi_env env,        ///< Node-API environment
+      void* externalData,  ///< Pointer to the external buffer to be used by
+                           ///< the array
+      size_t byteLength,   ///< Length of the external buffer to be used by the
+                           ///< array,
+                           ///  in bytes
+      Finalizer finalizeCallback,  ///< Function to be called when the array
+                                   ///< buffer is destroyed;
+                                   ///  must implement `void operator()(Env
+                                   ///  env, void* externalData, Hint* hint)`
+      Hint* finalizeHint  ///< Hint (second parameter) to be passed to the
+                          ///< finalize callback
+  );
+#endif  // NODE_API_NO_EXTERNAL_BUFFERS_ALLOWED
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  ArrayBuffer();  ///< Creates a new _empty_ ArrayBuffer instance.
+  ArrayBuffer(napi_env env,
+              napi_value value);  ///< Wraps a Node-API value primitive.
+
+  void* Data();         ///< Gets a pointer to the data buffer.
+  size_t ByteLength();  ///< Gets the length of the array buffer in bytes.
+
+#if NAPI_VERSION >= 7
+  bool IsDetached() const;
+  void Detach();
+#endif  // NAPI_VERSION >= 7
+};
+
+/// A JavaScript typed-array value with unknown array type.
+///
+/// For type-specific operations, cast to a `TypedArrayOf<T>` instance using the
+/// `As()` method:
+///
+///     Napi::TypedArray array = ...
+///     if (t.TypedArrayType() == napi_int32_array) {
+///         Napi::Int32Array int32Array = t.As<Napi::Int32Array>();
+///     }
+class TypedArray : public Object {
+ public:
+  static void CheckCast(napi_env env, napi_value value);
+
+  TypedArray();  ///< Creates a new _empty_ TypedArray instance.
+  TypedArray(napi_env env,
+             napi_value value);  ///< Wraps a Node-API value primitive.
+
+  napi_typedarray_type TypedArrayType()
+      const;  ///< Gets the type of this typed-array.
+  Napi::ArrayBuffer ArrayBuffer() const;  ///< Gets the backing array buffer.
+
+  uint8_t ElementSize()
+      const;  ///< Gets the size in bytes of one element in the array.
+  size_t ElementLength() const;  ///< Gets the number of elements in the array.
+  size_t ByteOffset()
+      const;  ///< Gets the offset into the buffer where the array starts.
+  size_t ByteLength() const;  ///< Gets the length of the array in bytes.
+
+ protected:
+  /// !cond INTERNAL
+  napi_typedarray_type _type;
+  size_t _length;
+
+  TypedArray(napi_env env,
+             napi_value value,
+             napi_typedarray_type type,
+             size_t length);
+
+  template <typename T>
+  static
+#if defined(NAPI_HAS_CONSTEXPR)
+      constexpr
+#endif
+      napi_typedarray_type
+      TypedArrayTypeForPrimitiveType() {
+    return std::is_same<T, int8_t>::value     ? napi_int8_array
+           : std::is_same<T, uint8_t>::value  ? napi_uint8_array
+           : std::is_same<T, int16_t>::value  ? napi_int16_array
+           : std::is_same<T, uint16_t>::value ? napi_uint16_array
+           : std::is_same<T, int32_t>::value  ? napi_int32_array
+           : std::is_same<T, uint32_t>::value ? napi_uint32_array
+           : std::is_same<T, float>::value    ? napi_float32_array
+           : std::is_same<T, double>::value   ? napi_float64_array
+#if NAPI_VERSION > 5
+           : std::is_same<T, int64_t>::value  ? napi_bigint64_array
+           : std::is_same<T, uint64_t>::value ? napi_biguint64_array
+#endif  // NAPI_VERSION > 5
+                                              : napi_int8_array;
+  }
+  /// !endcond
+};
+
+/// A JavaScript typed-array value with known array type.
+///
+/// Note while it is possible to create and access Uint8 "clamped" arrays using
+/// this class, the _clamping_ behavior is only applied in JavaScript.
+template <typename T>
+class TypedArrayOf : public TypedArray {
+ public:
+  /// Creates a new TypedArray instance over a new automatically-allocated array
+  /// buffer.
+  ///
+  /// The array type parameter can normally be omitted (because it is inferred
+  /// from the template parameter T), except when creating a "clamped" array:
+  ///
+  ///     Uint8Array::New(env, length, napi_uint8_clamped_array)
+  static TypedArrayOf New(
+      napi_env env,          ///< Node-API environment
+      size_t elementLength,  ///< Length of the created array, as a number of
+                             ///< elements
+#if defined(NAPI_HAS_CONSTEXPR)
+      napi_typedarray_type type =
+          TypedArray::TypedArrayTypeForPrimitiveType<T>()
+#else
+        napi_typedarray_type type
+#endif
+      ///< Type of array, if different from the default array type for the
+      ///< template parameter T.
+  );
+
+  /// Creates a new TypedArray instance over a provided array buffer.
+  ///
+  /// The array type parameter can normally be omitted (because it is inferred
+  /// from the template parameter T), except when creating a "clamped" array:
+  ///
+  ///     Uint8Array::New(env, length, buffer, 0, napi_uint8_clamped_array)
+  static TypedArrayOf New(
+      napi_env env,          ///< Node-API environment
+      size_t elementLength,  ///< Length of the created array, as a number of
+                             ///< elements
+      Napi::ArrayBuffer arrayBuffer,  ///< Backing array buffer instance to use
+      size_t bufferOffset,  ///< Offset into the array buffer where the
+                            ///< typed-array starts
+#if defined(NAPI_HAS_CONSTEXPR)
+      napi_typedarray_type type =
+          TypedArray::TypedArrayTypeForPrimitiveType<T>()
+#else
+        napi_typedarray_type type
+#endif
+      ///< Type of array, if different from the default array type for the
+      ///< template parameter T.
+  );
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  TypedArrayOf();  ///< Creates a new _empty_ TypedArrayOf instance.
+  TypedArrayOf(napi_env env,
+               napi_value value);  ///< Wraps a Node-API value primitive.
+
+  T& operator[](size_t index);  ///< Gets or sets an element in the array.
+  const T& operator[](size_t index) const;  ///< Gets an element in the array.
+
+  /// Gets a pointer to the array's backing buffer.
+  ///
+  /// This is not necessarily the same as the `ArrayBuffer::Data()` pointer,
+  /// because the typed-array may have a non-zero `ByteOffset()` into the
+  /// `ArrayBuffer`.
+  T* Data();
+
+  /// Gets a pointer to the array's backing buffer.
+  ///
+  /// This is not necessarily the same as the `ArrayBuffer::Data()` pointer,
+  /// because the typed-array may have a non-zero `ByteOffset()` into the
+  /// `ArrayBuffer`.
+  const T* Data() const;
+
+ private:
+  T* _data;
+
+  TypedArrayOf(napi_env env,
+               napi_value value,
+               napi_typedarray_type type,
+               size_t length,
+               T* data);
+};
+
+/// The DataView provides a low-level interface for reading/writing multiple
+/// number types in an ArrayBuffer irrespective of the platform's endianness.
+class DataView : public Object {
+ public:
+  static DataView New(napi_env env, Napi::ArrayBuffer arrayBuffer);
+  static DataView New(napi_env env,
+                      Napi::ArrayBuffer arrayBuffer,
+                      size_t byteOffset);
+  static DataView New(napi_env env,
+                      Napi::ArrayBuffer arrayBuffer,
+                      size_t byteOffset,
+                      size_t byteLength);
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  DataView();  ///< Creates a new _empty_ DataView instance.
+  DataView(napi_env env,
+           napi_value value);  ///< Wraps a Node-API value primitive.
+
+  Napi::ArrayBuffer ArrayBuffer() const;  ///< Gets the backing array buffer.
+  size_t ByteOffset()
+      const;  ///< Gets the offset into the buffer where the array starts.
+  size_t ByteLength() const;  ///< Gets the length of the array in bytes.
+
+  void* Data() const;
+
+  float GetFloat32(size_t byteOffset) const;
+  double GetFloat64(size_t byteOffset) const;
+  int8_t GetInt8(size_t byteOffset) const;
+  int16_t GetInt16(size_t byteOffset) const;
+  int32_t GetInt32(size_t byteOffset) const;
+  uint8_t GetUint8(size_t byteOffset) const;
+  uint16_t GetUint16(size_t byteOffset) const;
+  uint32_t GetUint32(size_t byteOffset) const;
+
+  void SetFloat32(size_t byteOffset, float value) const;
+  void SetFloat64(size_t byteOffset, double value) const;
+  void SetInt8(size_t byteOffset, int8_t value) const;
+  void SetInt16(size_t byteOffset, int16_t value) const;
+  void SetInt32(size_t byteOffset, int32_t value) const;
+  void SetUint8(size_t byteOffset, uint8_t value) const;
+  void SetUint16(size_t byteOffset, uint16_t value) const;
+  void SetUint32(size_t byteOffset, uint32_t value) const;
+
+ private:
+  template <typename T>
+  T ReadData(size_t byteOffset) const;
+
+  template <typename T>
+  void WriteData(size_t byteOffset, T value) const;
+
+  void* _data;
+  size_t _length;
+};
+
+class Function : public Object {
+ public:
+  using VoidCallback = void (*)(const CallbackInfo& info);
+  using Callback = Value (*)(const CallbackInfo& info);
+
+  template <VoidCallback cb>
+  static Function New(napi_env env,
+                      const char* utf8name = nullptr,
+                      void* data = nullptr);
+
+  template <Callback cb>
+  static Function New(napi_env env,
+                      const char* utf8name = nullptr,
+                      void* data = nullptr);
+
+  template <VoidCallback cb>
+  static Function New(napi_env env,
+                      const std::string& utf8name,
+                      void* data = nullptr);
+
+  template <Callback cb>
+  static Function New(napi_env env,
+                      const std::string& utf8name,
+                      void* data = nullptr);
+
+  /// Callable must implement operator() accepting a const CallbackInfo&
+  /// and return either void or Value.
+  template <typename Callable>
+  static Function New(napi_env env,
+                      Callable cb,
+                      const char* utf8name = nullptr,
+                      void* data = nullptr);
+  /// Callable must implement operator() accepting a const CallbackInfo&
+  /// and return either void or Value.
+  template <typename Callable>
+  static Function New(napi_env env,
+                      Callable cb,
+                      const std::string& utf8name,
+                      void* data = nullptr);
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Function();
+  Function(napi_env env, napi_value value);
+
+  MaybeOrValue<Value> operator()(
+      const std::initializer_list<napi_value>& args) const;
+
+  MaybeOrValue<Value> Call(const std::initializer_list<napi_value>& args) const;
+  MaybeOrValue<Value> Call(const std::vector<napi_value>& args) const;
+  MaybeOrValue<Value> Call(const std::vector<Value>& args) const;
+  MaybeOrValue<Value> Call(size_t argc, const napi_value* args) const;
+  MaybeOrValue<Value> Call(napi_value recv,
+                           const std::initializer_list<napi_value>& args) const;
+  MaybeOrValue<Value> Call(napi_value recv,
+                           const std::vector<napi_value>& args) const;
+  MaybeOrValue<Value> Call(napi_value recv,
+                           const std::vector<Value>& args) const;
+  MaybeOrValue<Value> Call(napi_value recv,
+                           size_t argc,
+                           const napi_value* args) const;
+
+  MaybeOrValue<Value> MakeCallback(
+      napi_value recv,
+      const std::initializer_list<napi_value>& args,
+      napi_async_context context = nullptr) const;
+  MaybeOrValue<Value> MakeCallback(napi_value recv,
+                                   const std::vector<napi_value>& args,
+                                   napi_async_context context = nullptr) const;
+  MaybeOrValue<Value> MakeCallback(napi_value recv,
+                                   size_t argc,
+                                   const napi_value* args,
+                                   napi_async_context context = nullptr) const;
+
+  MaybeOrValue<Object> New(const std::initializer_list<napi_value>& args) const;
+  MaybeOrValue<Object> New(const std::vector<napi_value>& args) const;
+  MaybeOrValue<Object> New(size_t argc, const napi_value* args) const;
+};
+
+class Promise : public Object {
+ public:
+  class Deferred {
+   public:
+    static Deferred New(napi_env env);
+    Deferred(napi_env env);
+
+    Napi::Promise Promise() const;
+    Napi::Env Env() const;
+
+    void Resolve(napi_value value) const;
+    void Reject(napi_value value) const;
+
+   private:
+    napi_env _env;
+    napi_deferred _deferred;
+    napi_value _promise;
+  };
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Promise(napi_env env, napi_value value);
+};
+
+template <typename T>
+class Buffer : public Uint8Array {
+ public:
+  static Buffer<T> New(napi_env env, size_t length);
+#ifndef NODE_API_NO_EXTERNAL_BUFFERS_ALLOWED
+  static Buffer<T> New(napi_env env, T* data, size_t length);
+
+  // Finalizer must implement `void operator()(Env env, T* data)`.
+  template <typename Finalizer>
+  static Buffer<T> New(napi_env env,
+                       T* data,
+                       size_t length,
+                       Finalizer finalizeCallback);
+  // Finalizer must implement `void operator()(Env env, T* data, Hint* hint)`.
+  template <typename Finalizer, typename Hint>
+  static Buffer<T> New(napi_env env,
+                       T* data,
+                       size_t length,
+                       Finalizer finalizeCallback,
+                       Hint* finalizeHint);
+#endif  // NODE_API_NO_EXTERNAL_BUFFERS_ALLOWED
+
+  static Buffer<T> NewOrCopy(napi_env env, T* data, size_t length);
+  // Finalizer must implement `void operator()(Env env, T* data)`.
+  template <typename Finalizer>
+  static Buffer<T> NewOrCopy(napi_env env,
+                             T* data,
+                             size_t length,
+                             Finalizer finalizeCallback);
+  // Finalizer must implement `void operator()(Env env, T* data, Hint* hint)`.
+  template <typename Finalizer, typename Hint>
+  static Buffer<T> NewOrCopy(napi_env env,
+                             T* data,
+                             size_t length,
+                             Finalizer finalizeCallback,
+                             Hint* finalizeHint);
+
+  static Buffer<T> Copy(napi_env env, const T* data, size_t length);
+
+  static void CheckCast(napi_env env, napi_value value);
+
+  Buffer();
+  Buffer(napi_env env, napi_value value);
+  size_t Length() const;
+  T* Data() const;
+
+ private:
+};
+
+/// Holds a counted reference to a value; initially a weak reference unless
+/// otherwise specified, may be changed to/from a strong reference by adjusting
+/// the refcount.
+///
+/// The referenced value is not immediately destroyed when the reference count
+/// is zero; it is merely then eligible for garbage-collection if there are no
+/// other references to the value.
+template <typename T>
+class Reference {
+ public:
+  static Reference<T> New(const T& value, uint32_t initialRefcount = 0);
+
+  Reference();
+  Reference(napi_env env, napi_ref ref);
+  ~Reference();
+
+  // A reference can be moved but cannot be copied.
+  Reference(Reference<T>&& other);
+  Reference<T>& operator=(Reference<T>&& other);
+  NAPI_DISALLOW_ASSIGN(Reference<T>)
+
+  operator napi_ref() const;
+  bool operator==(const Reference<T>& other) const;
+  bool operator!=(const Reference<T>& other) const;
+
+  Napi::Env Env() const;
+  bool IsEmpty() const;
+
+  // Note when getting the value of a Reference it is usually correct to do so
+  // within a HandleScope so that the value handle gets cleaned up efficiently.
+  T Value() const;
+
+  uint32_t Ref() const;
+  uint32_t Unref() const;
+  void Reset();
+  void Reset(const T& value, uint32_t refcount = 0);
+
+  // Call this on a reference that is declared as static data, to prevent its
+  // destructor from running at program shutdown time, which would attempt to
+  // reset the reference when the environment is no longer valid. Avoid using
+  // this if at all possible. If you do need to use static data, MAKE SURE to
+  // warn your users that your addon is NOT threadsafe.
+  void SuppressDestruct();
+
+ protected:
+  Reference(const Reference<T>&);
+
+  /// !cond INTERNAL
+  napi_env _env;
+  napi_ref _ref;
+  /// !endcond
+
+ private:
+  bool _suppressDestruct;
+};
+
+class ObjectReference : public Reference<Object> {
+ public:
+  ObjectReference();
+  ObjectReference(napi_env env, napi_ref ref);
+
+  // A reference can be moved but cannot be copied.
+  ObjectReference(Reference<Object>&& other);
+  ObjectReference& operator=(Reference<Object>&& other);
+  ObjectReference(ObjectReference&& other);
+  ObjectReference& operator=(ObjectReference&& other);
+  NAPI_DISALLOW_ASSIGN(ObjectReference)
+
+  MaybeOrValue<Napi::Value> Get(const char* utf8name) const;
+  MaybeOrValue<Napi::Value> Get(const std::string& utf8name) const;
+  MaybeOrValue<bool> Set(const char* utf8name, napi_value value) const;
+  MaybeOrValue<bool> Set(const char* utf8name, Napi::Value value) const;
+  MaybeOrValue<bool> Set(const char* utf8name, const char* utf8value) const;
+  MaybeOrValue<bool> Set(const char* utf8name, bool boolValue) const;
+  MaybeOrValue<bool> Set(const char* utf8name, double numberValue) const;
+  MaybeOrValue<bool> Set(const std::string& utf8name, napi_value value) const;
+  MaybeOrValue<bool> Set(const std::string& utf8name, Napi::Value value) const;
+  MaybeOrValue<bool> Set(const std::string& utf8name,
+                         std::string& utf8value) const;
+  MaybeOrValue<bool> Set(const std::string& utf8name, bool boolValue) const;
+  MaybeOrValue<bool> Set(const std::string& utf8name, double numberValue) const;
+
+  MaybeOrValue<Napi::Value> Get(uint32_t index) const;
+  MaybeOrValue<bool> Set(uint32_t index, const napi_value value) const;
+  MaybeOrValue<bool> Set(uint32_t index, const Napi::Value value) const;
+  MaybeOrValue<bool> Set(uint32_t index, const char* utf8value) const;
+  MaybeOrValue<bool> Set(uint32_t index, const std::string& utf8value) const;
+  MaybeOrValue<bool> Set(uint32_t index, bool boolValue) const;
+  MaybeOrValue<bool> Set(uint32_t index, double numberValue) const;
+
+ protected:
+  ObjectReference(const ObjectReference&);
+};
+
+class FunctionReference : public Reference<Function> {
+ public:
+  FunctionReference();
+  FunctionReference(napi_env env, napi_ref ref);
+
+  // A reference can be moved but cannot be copied.
+  FunctionReference(Reference<Function>&& other);
+  FunctionReference& operator=(Reference<Function>&& other);
+  FunctionReference(FunctionReference&& other);
+  FunctionReference& operator=(FunctionReference&& other);
+  NAPI_DISALLOW_ASSIGN_COPY(FunctionReference)
+
+  MaybeOrValue<Napi::Value> operator()(
+      const std::initializer_list<napi_value>& args) const;
+
+  MaybeOrValue<Napi::Value> Call(
+      const std::initializer_list<napi_value>& args) const;
+  MaybeOrValue<Napi::Value> Call(const std::vector<napi_value>& args) const;
+  MaybeOrValue<Napi::Value> Call(
+      napi_value recv, const std::initializer_list<napi_value>& args) const;
+  MaybeOrValue<Napi::Value> Call(napi_value recv,
+                                 const std::vector<napi_value>& args) const;
+  MaybeOrValue<Napi::Value> Call(napi_value recv,
+                                 size_t argc,
+                                 const napi_value* args) const;
+
+  MaybeOrValue<Napi::Value> MakeCallback(
+      napi_value recv,
+      const std::initializer_list<napi_value>& args,
+      napi_async_context context = nullptr) const;
+  MaybeOrValue<Napi::Value> MakeCallback(
+      napi_value recv,
+      const std::vector<napi_value>& args,
+      napi_async_context context = nullptr) const;
+  MaybeOrValue<Napi::Value> MakeCallback(
+      napi_value recv,
+      size_t argc,
+      const napi_value* args,
+      napi_async_context context = nullptr) const;
+
+  MaybeOrValue<Object> New(const std::initializer_list<napi_value>& args) const;
+  MaybeOrValue<Object> New(const std::vector<napi_value>& args) const;
+};
+
+// Shortcuts to creating a new reference with inferred type and refcount = 0.
+template <typename T>
+Reference<T> Weak(T value);
+ObjectReference Weak(Object value);
+FunctionReference Weak(Function value);
+
+// Shortcuts to creating a new reference with inferred type and refcount = 1.
+template <typename T>
+Reference<T> Persistent(T value);
+ObjectReference Persistent(Object value);
+FunctionReference Persistent(Function value);
+
+/// A persistent reference to a JavaScript error object. Use of this class
+/// depends somewhat on whether C++ exceptions are enabled at compile time.
+///
+/// ### Handling Errors With C++ Exceptions
+///
+/// If C++ exceptions are enabled, then the `Error` class extends
+/// `std::exception` and enables integrated error-handling for C++ exceptions
+/// and JavaScript exceptions.
+///
+/// If a Node-API call fails without executing any JavaScript code (for
+/// example due to an invalid argument), then the Node-API wrapper
+/// automatically converts and throws the error as a C++ exception of type
+/// `Napi::Error`. Or if a JavaScript function called by C++ code via Node-API
+/// throws a JavaScript exception, then the Node-API wrapper automatically
+/// converts and throws it as a C++ exception of type `Napi::Error`.
+///
+/// If a C++ exception of type `Napi::Error` escapes from a Node-API C++
+/// callback, then the Node-API wrapper automatically converts and throws it
+/// as a JavaScript exception. Therefore, catching a C++ exception of type
+/// `Napi::Error` prevents a JavaScript exception from being thrown.
+///
+/// #### Example 1A - Throwing a C++ exception:
+///
+///     Napi::Env env = ...
+///     throw Napi::Error::New(env, "Example exception");
+///
+/// Following C++ statements will not be executed. The exception will bubble
+/// up as a C++ exception of type `Napi::Error`, until it is either caught
+/// while still in C++, or else automatically propataged as a JavaScript
+/// exception when the callback returns to JavaScript.
+///
+/// #### Example 2A - Propagating a Node-API C++ exception:
+///
+///     Napi::Function jsFunctionThatThrows = someObj.As<Napi::Function>();
+///     Napi::Value result = jsFunctionThatThrows({ arg1, arg2 });
+///
+/// Following C++ statements will not be executed. The exception will bubble
+/// up as a C++ exception of type `Napi::Error`, until it is either caught
+/// while still in C++, or else automatically propagated as a JavaScript
+/// exception when the callback returns to JavaScript.
+///
+/// #### Example 3A - Handling a Node-API C++ exception:
+///
+///     Napi::Function jsFunctionThatThrows = someObj.As<Napi::Function>();
+///     Napi::Value result;
+///     try {
+///        result = jsFunctionThatThrows({ arg1, arg2 });
+///     } catch (const Napi::Error& e) {
+///       cerr << "Caught JavaScript exception: " + e.what();
+///     }
+///
+/// Since the exception was caught here, it will not be propagated as a
+/// JavaScript exception.
+///
+/// ### Handling Errors Without C++ Exceptions
+///
+/// If C++ exceptions are disabled (by defining `NAPI_DISABLE_CPP_EXCEPTIONS`)
+/// then this class does not extend `std::exception`, and APIs in the `Napi`
+/// namespace do not throw C++ exceptions when they fail. Instead, they raise
+/// _pending_ JavaScript exceptions and return _empty_ `Value`s. Calling code
+/// should check `Value::IsEmpty()` before attempting to use a returned value,
+/// and may use methods on the `Env` class to check for, get, and clear a
+/// pending JavaScript exception. If the pending exception is not cleared, it
+/// will be thrown when the native callback returns to JavaScript.
+///
+/// #### Example 1B - Throwing a JS exception
+///
+///     Napi::Env env = ...
+///     Napi::Error::New(env, "Example
+///     exception").ThrowAsJavaScriptException(); return;
+///
+/// After throwing a JS exception, the code should generally return
+/// immediately from the native callback, after performing any necessary
+/// cleanup.
+///
+/// #### Example 2B - Propagating a Node-API JS exception:
+///
+///     Napi::Function jsFunctionThatThrows = someObj.As<Napi::Function>();
+///     Napi::Value result = jsFunctionThatThrows({ arg1, arg2 });
+///     if (result.IsEmpty()) return;
+///
+/// An empty value result from a Node-API call indicates an error occurred,
+/// and a JavaScript exception is pending. To let the exception propagate, the
+/// code should generally return immediately from the native callback, after
+/// performing any necessary cleanup.
+///
+/// #### Example 3B - Handling a Node-API JS exception:
+///
+///     Napi::Function jsFunctionThatThrows = someObj.As<Napi::Function>();
+///     Napi::Value result = jsFunctionThatThrows({ arg1, arg2 });
+///     if (result.IsEmpty()) {
+///       Napi::Error e = env.GetAndClearPendingException();
+///       cerr << "Caught JavaScript exception: " + e.Message();
+///     }
+///
+/// Since the exception was cleared here, it will not be propagated as a
+/// JavaScript exception after the native callback returns.
+class Error : public ObjectReference
+#ifdef NAPI_CPP_EXCEPTIONS
+    ,
+              public std::exception
+#endif  // NAPI_CPP_EXCEPTIONS
+{
+ public:
+  static Error New(napi_env env);
+  static Error New(napi_env env, const char* message);
+  static Error New(napi_env env, const std::string& message);
+
+  static NAPI_NO_RETURN void Fatal(const char* location, const char* message);
+
+  Error();
+  Error(napi_env env, napi_value value);
+
+  // An error can be moved or copied.
+  Error(Error&& other);
+  Error& operator=(Error&& other);
+  Error(const Error&);
+  Error& operator=(const Error&);
+
+  const std::string& Message() const NAPI_NOEXCEPT;
+  void ThrowAsJavaScriptException() const;
+
+  Object Value() const;
+
+#ifdef NAPI_CPP_EXCEPTIONS
+  const char* what() const NAPI_NOEXCEPT override;
+#endif  // NAPI_CPP_EXCEPTIONS
+
+ protected:
+  /// !cond INTERNAL
+  using create_error_fn = napi_status (*)(napi_env envb,
+                                          napi_value code,
+                                          napi_value msg,
+                                          napi_value* result);
+
+  template <typename TError>
+  static TError New(napi_env env,
+                    const char* message,
+                    size_t length,
+                    create_error_fn create_error);
+  /// !endcond
+
+ private:
+  static inline const char* ERROR_WRAP_VALUE() NAPI_NOEXCEPT;
+  mutable std::string _message;
+};
+
+class TypeError : public Error {
+ public:
+  static TypeError New(napi_env env, const char* message);
+  static TypeError New(napi_env env, const std::string& message);
+
+  TypeError();
+  TypeError(napi_env env, napi_value value);
+};
+
+class RangeError : public Error {
+ public:
+  static RangeError New(napi_env env, const char* message);
+  static RangeError New(napi_env env, const std::string& message);
+
+  RangeError();
+  RangeError(napi_env env, napi_value value);
+};
+
+#if NAPI_VERSION > 8
+class SyntaxError : public Error {
+ public:
+  static SyntaxError New(napi_env env, const char* message);
+  static SyntaxError New(napi_env env, const std::string& message);
+
+  SyntaxError();
+  SyntaxError(napi_env env, napi_value value);
+};
+#endif  // NAPI_VERSION > 8
+
+class CallbackInfo {
+ public:
+  CallbackInfo(napi_env env, napi_callback_info info);
+  ~CallbackInfo();
+
+  // Disallow copying to prevent multiple free of _dynamicArgs
+  NAPI_DISALLOW_ASSIGN_COPY(CallbackInfo)
+
+  Napi::Env Env() const;
+  Value NewTarget() const;
+  bool IsConstructCall() const;
+  size_t Length() const;
+  const Value operator[](size_t index) const;
+  Value This() const;
+  void* Data() const;
+  void SetData(void* data);
+  explicit operator napi_callback_info() const;
+
+ private:
+  const size_t _staticArgCount = 6;
+  napi_env _env;
+  napi_callback_info _info;
+  napi_value _this;
+  size_t _argc;
+  napi_value* _argv;
+  napi_value _staticArgs[6];
+  napi_value* _dynamicArgs;
+  void* _data;
+};
+
+class PropertyDescriptor {
+ public:
+  using GetterCallback = Napi::Value (*)(const Napi::CallbackInfo& info);
+  using SetterCallback = void (*)(const Napi::CallbackInfo& info);
+
+#ifndef NODE_ADDON_API_DISABLE_DEPRECATED
+  template <typename Getter>
+  static PropertyDescriptor Accessor(
+      const char* utf8name,
+      Getter getter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter>
+  static PropertyDescriptor Accessor(
+      const std::string& utf8name,
+      Getter getter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter>
+  static PropertyDescriptor Accessor(
+      napi_value name,
+      Getter getter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter>
+  static PropertyDescriptor Accessor(
+      Name name,
+      Getter getter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter, typename Setter>
+  static PropertyDescriptor Accessor(
+      const char* utf8name,
+      Getter getter,
+      Setter setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter, typename Setter>
+  static PropertyDescriptor Accessor(
+      const std::string& utf8name,
+      Getter getter,
+      Setter setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter, typename Setter>
+  static PropertyDescriptor Accessor(
+      napi_value name,
+      Getter getter,
+      Setter setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter, typename Setter>
+  static PropertyDescriptor Accessor(
+      Name name,
+      Getter getter,
+      Setter setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Callable>
+  static PropertyDescriptor Function(
+      const char* utf8name,
+      Callable cb,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Callable>
+  static PropertyDescriptor Function(
+      const std::string& utf8name,
+      Callable cb,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Callable>
+  static PropertyDescriptor Function(
+      napi_value name,
+      Callable cb,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Callable>
+  static PropertyDescriptor Function(
+      Name name,
+      Callable cb,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+#endif  // !NODE_ADDON_API_DISABLE_DEPRECATED
+
+  template <GetterCallback Getter>
+  static PropertyDescriptor Accessor(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+
+  template <GetterCallback Getter>
+  static PropertyDescriptor Accessor(
+      const std::string& utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+
+  template <GetterCallback Getter>
+  static PropertyDescriptor Accessor(
+      Name name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+
+  template <GetterCallback Getter, SetterCallback Setter>
+  static PropertyDescriptor Accessor(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+
+  template <GetterCallback Getter, SetterCallback Setter>
+  static PropertyDescriptor Accessor(
+      const std::string& utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+
+  template <GetterCallback Getter, SetterCallback Setter>
+  static PropertyDescriptor Accessor(
+      Name name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+
+  template <typename Getter>
+  static PropertyDescriptor Accessor(
+      Napi::Env env,
+      Napi::Object object,
+      const char* utf8name,
+      Getter getter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter>
+  static PropertyDescriptor Accessor(
+      Napi::Env env,
+      Napi::Object object,
+      const std::string& utf8name,
+      Getter getter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter>
+  static PropertyDescriptor Accessor(
+      Napi::Env env,
+      Napi::Object object,
+      Name name,
+      Getter getter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter, typename Setter>
+  static PropertyDescriptor Accessor(
+      Napi::Env env,
+      Napi::Object object,
+      const char* utf8name,
+      Getter getter,
+      Setter setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter, typename Setter>
+  static PropertyDescriptor Accessor(
+      Napi::Env env,
+      Napi::Object object,
+      const std::string& utf8name,
+      Getter getter,
+      Setter setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Getter, typename Setter>
+  static PropertyDescriptor Accessor(
+      Napi::Env env,
+      Napi::Object object,
+      Name name,
+      Getter getter,
+      Setter setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Callable>
+  static PropertyDescriptor Function(
+      Napi::Env env,
+      Napi::Object object,
+      const char* utf8name,
+      Callable cb,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Callable>
+  static PropertyDescriptor Function(
+      Napi::Env env,
+      Napi::Object object,
+      const std::string& utf8name,
+      Callable cb,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <typename Callable>
+  static PropertyDescriptor Function(
+      Napi::Env env,
+      Napi::Object object,
+      Name name,
+      Callable cb,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor Value(
+      const char* utf8name,
+      napi_value value,
+      napi_property_attributes attributes = napi_default);
+  static PropertyDescriptor Value(
+      const std::string& utf8name,
+      napi_value value,
+      napi_property_attributes attributes = napi_default);
+  static PropertyDescriptor Value(
+      napi_value name,
+      napi_value value,
+      napi_property_attributes attributes = napi_default);
+  static PropertyDescriptor Value(
+      Name name,
+      Napi::Value value,
+      napi_property_attributes attributes = napi_default);
+
+  PropertyDescriptor(napi_property_descriptor desc);
+
+  operator napi_property_descriptor&();
+  operator const napi_property_descriptor&() const;
+
+ private:
+  napi_property_descriptor _desc;
+};
+
+/// Property descriptor for use with `ObjectWrap::DefineClass()`.
+///
+/// This is different from the standalone `PropertyDescriptor` because it is
+/// specific to each `ObjectWrap<T>` subclass. This prevents using descriptors
+/// from a different class when defining a new class (preventing the callbacks
+/// from having incorrect `this` pointers).
+template <typename T>
+class ClassPropertyDescriptor {
+ public:
+  ClassPropertyDescriptor(napi_property_descriptor desc) : _desc(desc) {}
+
+  operator napi_property_descriptor&() { return _desc; }
+  operator const napi_property_descriptor&() const { return _desc; }
+
+ private:
+  napi_property_descriptor _desc;
+};
+
+template <typename T, typename TCallback>
+struct MethodCallbackData {
+  TCallback callback;
+  void* data;
+};
+
+template <typename T, typename TGetterCallback, typename TSetterCallback>
+struct AccessorCallbackData {
+  TGetterCallback getterCallback;
+  TSetterCallback setterCallback;
+  void* data;
+};
+
+template <typename T>
+class InstanceWrap {
+ public:
+  using InstanceVoidMethodCallback = void (T::*)(const CallbackInfo& info);
+  using InstanceMethodCallback = Napi::Value (T::*)(const CallbackInfo& info);
+  using InstanceGetterCallback = Napi::Value (T::*)(const CallbackInfo& info);
+  using InstanceSetterCallback = void (T::*)(const CallbackInfo& info,
+                                             const Napi::Value& value);
+
+  using PropertyDescriptor = ClassPropertyDescriptor<T>;
+
+  static PropertyDescriptor InstanceMethod(
+      const char* utf8name,
+      InstanceVoidMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor InstanceMethod(
+      const char* utf8name,
+      InstanceMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor InstanceMethod(
+      Symbol name,
+      InstanceVoidMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor InstanceMethod(
+      Symbol name,
+      InstanceMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <InstanceVoidMethodCallback method>
+  static PropertyDescriptor InstanceMethod(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <InstanceMethodCallback method>
+  static PropertyDescriptor InstanceMethod(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <InstanceVoidMethodCallback method>
+  static PropertyDescriptor InstanceMethod(
+      Symbol name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <InstanceMethodCallback method>
+  static PropertyDescriptor InstanceMethod(
+      Symbol name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor InstanceAccessor(
+      const char* utf8name,
+      InstanceGetterCallback getter,
+      InstanceSetterCallback setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor InstanceAccessor(
+      Symbol name,
+      InstanceGetterCallback getter,
+      InstanceSetterCallback setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <InstanceGetterCallback getter,
+            InstanceSetterCallback setter = nullptr>
+  static PropertyDescriptor InstanceAccessor(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <InstanceGetterCallback getter,
+            InstanceSetterCallback setter = nullptr>
+  static PropertyDescriptor InstanceAccessor(
+      Symbol name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor InstanceValue(
+      const char* utf8name,
+      Napi::Value value,
+      napi_property_attributes attributes = napi_default);
+  static PropertyDescriptor InstanceValue(
+      Symbol name,
+      Napi::Value value,
+      napi_property_attributes attributes = napi_default);
+
+ protected:
+  static void AttachPropData(napi_env env,
+                             napi_value value,
+                             const napi_property_descriptor* prop);
+
+ private:
+  using This = InstanceWrap<T>;
+
+  using InstanceVoidMethodCallbackData =
+      MethodCallbackData<T, InstanceVoidMethodCallback>;
+  using InstanceMethodCallbackData =
+      MethodCallbackData<T, InstanceMethodCallback>;
+  using InstanceAccessorCallbackData =
+      AccessorCallbackData<T, InstanceGetterCallback, InstanceSetterCallback>;
+
+  static napi_value InstanceVoidMethodCallbackWrapper(napi_env env,
+                                                      napi_callback_info info);
+  static napi_value InstanceMethodCallbackWrapper(napi_env env,
+                                                  napi_callback_info info);
+  static napi_value InstanceGetterCallbackWrapper(napi_env env,
+                                                  napi_callback_info info);
+  static napi_value InstanceSetterCallbackWrapper(napi_env env,
+                                                  napi_callback_info info);
+
+  template <InstanceSetterCallback method>
+  static napi_value WrappedMethod(napi_env env,
+                                  napi_callback_info info) NAPI_NOEXCEPT;
+
+  template <InstanceSetterCallback setter>
+  struct SetterTag {};
+
+  template <InstanceSetterCallback setter>
+  static napi_callback WrapSetter(SetterTag<setter>) NAPI_NOEXCEPT {
+    return &This::WrappedMethod<setter>;
+  }
+  static napi_callback WrapSetter(SetterTag<nullptr>) NAPI_NOEXCEPT {
+    return nullptr;
+  }
+};
+
+/// Base class to be extended by C++ classes exposed to JavaScript; each C++
+/// class instance gets "wrapped" by a JavaScript object that is managed by this
+/// class.
+///
+/// At initialization time, the `DefineClass()` method must be used to
+/// hook up the accessor and method callbacks. It takes a list of
+/// property descriptors, which can be constructed via the various
+/// static methods on the base class.
+///
+/// #### Example:
+///
+///     class Example: public Napi::ObjectWrap<Example> {
+///       public:
+///         static void Initialize(Napi::Env& env, Napi::Object& target) {
+///           Napi::Function constructor = DefineClass(env, "Example", {
+///             InstanceAccessor<&Example::GetSomething,
+///             &Example::SetSomething>("value"),
+///             InstanceMethod<&Example::DoSomething>("doSomething"),
+///           });
+///           target.Set("Example", constructor);
+///         }
+///
+///         Example(const Napi::CallbackInfo& info); // Constructor
+///         Napi::Value GetSomething(const Napi::CallbackInfo& info);
+///         void SetSomething(const Napi::CallbackInfo& info, const Napi::Value&
+///         value); Napi::Value DoSomething(const Napi::CallbackInfo& info);
+///     }
+template <typename T>
+class ObjectWrap : public InstanceWrap<T>, public Reference<Object> {
+ public:
+  ObjectWrap(const CallbackInfo& callbackInfo);
+  virtual ~ObjectWrap();
+
+  static T* Unwrap(Object wrapper);
+
+  // Methods exposed to JavaScript must conform to one of these callback
+  // signatures.
+  using StaticVoidMethodCallback = void (*)(const CallbackInfo& info);
+  using StaticMethodCallback = Napi::Value (*)(const CallbackInfo& info);
+  using StaticGetterCallback = Napi::Value (*)(const CallbackInfo& info);
+  using StaticSetterCallback = void (*)(const CallbackInfo& info,
+                                        const Napi::Value& value);
+
+  using PropertyDescriptor = ClassPropertyDescriptor<T>;
+
+  static Function DefineClass(
+      Napi::Env env,
+      const char* utf8name,
+      const std::initializer_list<PropertyDescriptor>& properties,
+      void* data = nullptr);
+  static Function DefineClass(Napi::Env env,
+                              const char* utf8name,
+                              const std::vector<PropertyDescriptor>& properties,
+                              void* data = nullptr);
+  static PropertyDescriptor StaticMethod(
+      const char* utf8name,
+      StaticVoidMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor StaticMethod(
+      const char* utf8name,
+      StaticMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor StaticMethod(
+      Symbol name,
+      StaticVoidMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor StaticMethod(
+      Symbol name,
+      StaticMethodCallback method,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <StaticVoidMethodCallback method>
+  static PropertyDescriptor StaticMethod(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <StaticVoidMethodCallback method>
+  static PropertyDescriptor StaticMethod(
+      Symbol name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <StaticMethodCallback method>
+  static PropertyDescriptor StaticMethod(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <StaticMethodCallback method>
+  static PropertyDescriptor StaticMethod(
+      Symbol name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor StaticAccessor(
+      const char* utf8name,
+      StaticGetterCallback getter,
+      StaticSetterCallback setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor StaticAccessor(
+      Symbol name,
+      StaticGetterCallback getter,
+      StaticSetterCallback setter,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <StaticGetterCallback getter, StaticSetterCallback setter = nullptr>
+  static PropertyDescriptor StaticAccessor(
+      const char* utf8name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  template <StaticGetterCallback getter, StaticSetterCallback setter = nullptr>
+  static PropertyDescriptor StaticAccessor(
+      Symbol name,
+      napi_property_attributes attributes = napi_default,
+      void* data = nullptr);
+  static PropertyDescriptor StaticValue(
+      const char* utf8name,
+      Napi::Value value,
+      napi_property_attributes attributes = napi_default);
+  static PropertyDescriptor StaticValue(
+      Symbol name,
+      Napi::Value value,
+      napi_property_attributes attributes = napi_default);
+  static Napi::Value OnCalledAsFunction(const Napi::CallbackInfo& callbackInfo);
+  virtual void Finalize(Napi::Env env);
+
+ private:
+  using This = ObjectWrap<T>;
+
+  static napi_value ConstructorCallbackWrapper(napi_env env,
+                                               napi_callback_info info);
+  static napi_value StaticVoidMethodCallbackWrapper(napi_env env,
+                                                    napi_callback_info info);
+  static napi_value StaticMethodCallbackWrapper(napi_env env,
+                                                napi_callback_info info);
+  static napi_value StaticGetterCallbackWrapper(napi_env env,
+                                                napi_callback_info info);
+  static napi_value StaticSetterCallbackWrapper(napi_env env,
+                                                napi_callback_info info);
+  static void FinalizeCallback(napi_env env, void* data, void* hint);
+  static Function DefineClass(Napi::Env env,
+                              const char* utf8name,
+                              const size_t props_count,
+                              const napi_property_descriptor* props,
+                              void* data = nullptr);
+
+  using StaticVoidMethodCallbackData =
+      MethodCallbackData<T, StaticVoidMethodCallback>;
+  using StaticMethodCallbackData = MethodCallbackData<T, StaticMethodCallback>;
+
+  using StaticAccessorCallbackData =
+      AccessorCallbackData<T, StaticGetterCallback, StaticSetterCallback>;
+
+  template <StaticSetterCallback method>
+  static napi_value WrappedMethod(napi_env env,
+                                  napi_callback_info info) NAPI_NOEXCEPT;
+
+  template <StaticSetterCallback setter>
+  struct StaticSetterTag {};
+
+  template <StaticSetterCallback setter>
+  static napi_callback WrapStaticSetter(StaticSetterTag<setter>) NAPI_NOEXCEPT {
+    return &This::WrappedMethod<setter>;
+  }
+  static napi_callback WrapStaticSetter(StaticSetterTag<nullptr>)
+      NAPI_NOEXCEPT {
+    return nullptr;
+  }
+
+  bool _construction_failed = true;
+};
+
+class HandleScope {
+ public:
+  HandleScope(napi_env env, napi_handle_scope scope);
+  explicit HandleScope(Napi::Env env);
+  ~HandleScope();
+
+  // Disallow copying to prevent double close of napi_handle_scope
+  NAPI_DISALLOW_ASSIGN_COPY(HandleScope)
+
+  operator napi_handle_scope() const;
+
+  Napi::Env Env() const;
+
+ private:
+  napi_env _env;
+  napi_handle_scope _scope;
+};
+
+class EscapableHandleScope {
+ public:
+  EscapableHandleScope(napi_env env, napi_escapable_handle_scope scope);
+  explicit EscapableHandleScope(Napi::Env env);
+  ~EscapableHandleScope();
+
+  // Disallow copying to prevent double close of napi_escapable_handle_scope
+  NAPI_DISALLOW_ASSIGN_COPY(EscapableHandleScope)
+
+  operator napi_escapable_handle_scope() const;
+
+  Napi::Env Env() const;
+  Value Escape(napi_value escapee);
+
+ private:
+  napi_env _env;
+  napi_escapable_handle_scope _scope;
+};
+
+#if (NAPI_VERSION > 2)
+class CallbackScope {
+ public:
+  CallbackScope(napi_env env, napi_callback_scope scope);
+  CallbackScope(napi_env env, napi_async_context context);
+  virtual ~CallbackScope();
+
+  // Disallow copying to prevent double close of napi_callback_scope
+  NAPI_DISALLOW_ASSIGN_COPY(CallbackScope)
+
+  operator napi_callback_scope() const;
+
+  Napi::Env Env() const;
+
+ private:
+  napi_env _env;
+  napi_callback_scope _scope;
+};
+#endif
+
+class AsyncContext {
+ public:
+  explicit AsyncContext(napi_env env, const char* resource_name);
+  explicit AsyncContext(napi_env env,
+                        const char* resource_name,
+                        const Object& resource);
+  virtual ~AsyncContext();
+
+  AsyncContext(AsyncContext&& other);
+  AsyncContext& operator=(AsyncContext&& other);
+  NAPI_DISALLOW_ASSIGN_COPY(AsyncContext)
+
+  operator napi_async_context() const;
+
+  Napi::Env Env() const;
+
+ private:
+  napi_env _env;
+  napi_async_context _context;
+};
+
+#if NAPI_HAS_THREADS
+class AsyncWorker {
+ public:
+  virtual ~AsyncWorker();
+
+  NAPI_DISALLOW_ASSIGN_COPY(AsyncWorker)
+
+  operator napi_async_work() const;
+
+  Napi::Env Env() const;
+
+  void Queue();
+  void Cancel();
+  void SuppressDestruct();
+
+  ObjectReference& Receiver();
+  FunctionReference& Callback();
+
+  virtual void OnExecute(Napi::Env env);
+  virtual void OnWorkComplete(Napi::Env env, napi_status status);
+
+ protected:
+  explicit AsyncWorker(const Function& callback);
+  explicit AsyncWorker(const Function& callback, const char* resource_name);
+  explicit AsyncWorker(const Function& callback,
+                       const char* resource_name,
+                       const Object& resource);
+  explicit AsyncWorker(const Object& receiver, const Function& callback);
+  explicit AsyncWorker(const Object& receiver,
+                       const Function& callback,
+                       const char* resource_name);
+  explicit AsyncWorker(const Object& receiver,
+                       const Function& callback,
+                       const char* resource_name,
+                       const Object& resource);
+
+  explicit AsyncWorker(Napi::Env env);
+  explicit AsyncWorker(Napi::Env env, const char* resource_name);
+  explicit AsyncWorker(Napi::Env env,
+                       const char* resource_name,
+                       const Object& resource);
+
+  virtual void Execute() = 0;
+  virtual void OnOK();
+  virtual void OnError(const Error& e);
+  virtual void Destroy();
+  virtual std::vector<napi_value> GetResult(Napi::Env env);
+
+  void SetError(const std::string& error);
+
+ private:
+  static inline void OnAsyncWorkExecute(napi_env env, void* asyncworker);
+  static inline void OnAsyncWorkComplete(napi_env env,
+                                         napi_status status,
+                                         void* asyncworker);
+
+  napi_env _env;
+  napi_async_work _work;
+  ObjectReference _receiver;
+  FunctionReference _callback;
+  std::string _error;
+  bool _suppress_destruct;
+};
+#endif  // NAPI_HAS_THREADS
+
+#if (NAPI_VERSION > 3 && NAPI_HAS_THREADS)
+class ThreadSafeFunction {
+ public:
+  // This API may only be called from the main thread.
+  template <typename ResourceString>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString, typename ContextType>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                ContextType* context);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString, typename Finalizer>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                Finalizer finalizeCallback);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString,
+            typename Finalizer,
+            typename FinalizerDataType>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                Finalizer finalizeCallback,
+                                FinalizerDataType* data);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString, typename ContextType, typename Finalizer>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                ContextType* context,
+                                Finalizer finalizeCallback);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString,
+            typename ContextType,
+            typename Finalizer,
+            typename FinalizerDataType>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                ContextType* context,
+                                Finalizer finalizeCallback,
+                                FinalizerDataType* data);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                const Object& resource,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString, typename ContextType>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                const Object& resource,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                ContextType* context);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString, typename Finalizer>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                const Object& resource,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                Finalizer finalizeCallback);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString,
+            typename Finalizer,
+            typename FinalizerDataType>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                const Object& resource,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                Finalizer finalizeCallback,
+                                FinalizerDataType* data);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString, typename ContextType, typename Finalizer>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                const Object& resource,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                ContextType* context,
+                                Finalizer finalizeCallback);
+
+  // This API may only be called from the main thread.
+  template <typename ResourceString,
+            typename ContextType,
+            typename Finalizer,
+            typename FinalizerDataType>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                const Object& resource,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                ContextType* context,
+                                Finalizer finalizeCallback,
+                                FinalizerDataType* data);
+
+  ThreadSafeFunction();
+  ThreadSafeFunction(napi_threadsafe_function tsFunctionValue);
+
+  operator napi_threadsafe_function() const;
+
+  // This API may be called from any thread.
+  napi_status BlockingCall() const;
+
+  // This API may be called from any thread.
+  template <typename Callback>
+  napi_status BlockingCall(Callback callback) const;
+
+  // This API may be called from any thread.
+  template <typename DataType, typename Callback>
+  napi_status BlockingCall(DataType* data, Callback callback) const;
+
+  // This API may be called from any thread.
+  napi_status NonBlockingCall() const;
+
+  // This API may be called from any thread.
+  template <typename Callback>
+  napi_status NonBlockingCall(Callback callback) const;
+
+  // This API may be called from any thread.
+  template <typename DataType, typename Callback>
+  napi_status NonBlockingCall(DataType* data, Callback callback) const;
+
+  // This API may only be called from the main thread.
+  void Ref(napi_env env) const;
+
+  // This API may only be called from the main thread.
+  void Unref(napi_env env) const;
+
+  // This API may be called from any thread.
+  napi_status Acquire() const;
+
+  // This API may be called from any thread.
+  napi_status Release() const;
+
+  // This API may be called from any thread.
+  napi_status Abort() const;
+
+  struct ConvertibleContext {
+    template <class T>
+    operator T*() {
+      return static_cast<T*>(context);
+    }
+    void* context;
+  };
+
+  // This API may be called from any thread.
+  ConvertibleContext GetContext() const;
+
+ private:
+  using CallbackWrapper = std::function<void(Napi::Env, Napi::Function)>;
+
+  template <typename ResourceString,
+            typename ContextType,
+            typename Finalizer,
+            typename FinalizerDataType>
+  static ThreadSafeFunction New(napi_env env,
+                                const Function& callback,
+                                const Object& resource,
+                                ResourceString resourceName,
+                                size_t maxQueueSize,
+                                size_t initialThreadCount,
+                                ContextType* context,
+                                Finalizer finalizeCallback,
+                                FinalizerDataType* data,
+                                napi_finalize wrapper);
+
+  napi_status CallInternal(CallbackWrapper* callbackWrapper,
+                           napi_threadsafe_function_call_mode mode) const;
+
+  static void CallJS(napi_env env,
+                     napi_value jsCallback,
+                     void* context,
+                     void* data);
+
+  napi_threadsafe_function _tsfn;
+};
+
+// A TypedThreadSafeFunction by default has no context (nullptr) and can
+// accept any type (void) to its CallJs.
+template <typename ContextType = std::nullptr_t,
+          typename DataType = void,
+          void (*CallJs)(Napi::Env, Napi::Function, ContextType*, DataType*) =
+              nullptr>
+class TypedThreadSafeFunction {
+ public:
+  // This API may only be called from the main thread.
+  // Helper function that returns nullptr if running Node-API 5+, otherwise a
+  // non-empty, no-op Function. This provides the ability to specify at
+  // compile-time a callback parameter to `New` that safely does no action
+  // when targeting _any_ Node-API version.
+#if NAPI_VERSION > 4
+  static std::nullptr_t EmptyFunctionFactory(Napi::Env env);
+#else
+  static Napi::Function EmptyFunctionFactory(Napi::Env env);
+#endif
+  static Napi::Function FunctionOrEmpty(Napi::Env env,
+                                        Napi::Function& callback);
+
+#if NAPI_VERSION > 4
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [missing] Resource [missing] Finalizer [missing]
+  template <typename ResourceString>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context = nullptr);
+
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [missing] Resource [passed] Finalizer [missing]
+  template <typename ResourceString>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      const Object& resource,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context = nullptr);
+
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [missing] Resource [missing] Finalizer [passed]
+  template <typename ResourceString,
+            typename Finalizer,
+            typename FinalizerDataType = void>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context,
+      Finalizer finalizeCallback,
+      FinalizerDataType* data = nullptr);
+
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [missing] Resource [passed] Finalizer [passed]
+  template <typename ResourceString,
+            typename Finalizer,
+            typename FinalizerDataType = void>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      const Object& resource,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context,
+      Finalizer finalizeCallback,
+      FinalizerDataType* data = nullptr);
+#endif
+
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [passed] Resource [missing] Finalizer [missing]
+  template <typename ResourceString>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      const Function& callback,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context = nullptr);
+
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [passed] Resource [passed] Finalizer [missing]
+  template <typename ResourceString>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      const Function& callback,
+      const Object& resource,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context = nullptr);
+
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [passed] Resource [missing] Finalizer [passed]
+  template <typename ResourceString,
+            typename Finalizer,
+            typename FinalizerDataType = void>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      const Function& callback,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context,
+      Finalizer finalizeCallback,
+      FinalizerDataType* data = nullptr);
+
+  // This API may only be called from the main thread.
+  // Creates a new threadsafe function with:
+  //   Callback [passed] Resource [passed] Finalizer [passed]
+  template <typename CallbackType,
+            typename ResourceString,
+            typename Finalizer,
+            typename FinalizerDataType>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      CallbackType callback,
+      const Object& resource,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context,
+      Finalizer finalizeCallback,
+      FinalizerDataType* data = nullptr);
+
+  TypedThreadSafeFunction();
+  TypedThreadSafeFunction(napi_threadsafe_function tsFunctionValue);
+
+  operator napi_threadsafe_function() const;
+
+  // This API may be called from any thread.
+  napi_status BlockingCall(DataType* data = nullptr) const;
+
+  // This API may be called from any thread.
+  napi_status NonBlockingCall(DataType* data = nullptr) const;
+
+  // This API may only be called from the main thread.
+  void Ref(napi_env env) const;
+
+  // This API may only be called from the main thread.
+  void Unref(napi_env env) const;
+
+  // This API may be called from any thread.
+  napi_status Acquire() const;
+
+  // This API may be called from any thread.
+  napi_status Release() const;
+
+  // This API may be called from any thread.
+  napi_status Abort() const;
+
+  // This API may be called from any thread.
+  ContextType* GetContext() const;
+
+ private:
+  template <typename ResourceString,
+            typename Finalizer,
+            typename FinalizerDataType>
+  static TypedThreadSafeFunction<ContextType, DataType, CallJs> New(
+      napi_env env,
+      const Function& callback,
+      const Object& resource,
+      ResourceString resourceName,
+      size_t maxQueueSize,
+      size_t initialThreadCount,
+      ContextType* context,
+      Finalizer finalizeCallback,
+      FinalizerDataType* data,
+      napi_finalize wrapper);
+
+  static void CallJsInternal(napi_env env,
+                             napi_value jsCallback,
+                             void* context,
+                             void* data);
+
+ protected:
+  napi_threadsafe_function _tsfn;
+};
+template <typename DataType>
+class AsyncProgressWorkerBase : public AsyncWorker {
+ public:
+  virtual void OnWorkProgress(DataType* data) = 0;
+  class ThreadSafeData {
+   public:
+    ThreadSafeData(AsyncProgressWorkerBase* asyncprogressworker, DataType* data)
+        : _asyncprogressworker(asyncprogressworker), _data(data) {}
+
+    AsyncProgressWorkerBase* asyncprogressworker() {
+      return _asyncprogressworker;
+    };
+    DataType* data() { return _data; };
+
+   private:
+    AsyncProgressWorkerBase* _asyncprogressworker;
+    DataType* _data;
+  };
+  void OnWorkComplete(Napi::Env env, napi_status status) override;
+
+ protected:
+  explicit AsyncProgressWorkerBase(const Object& receiver,
+                                   const Function& callback,
+                                   const char* resource_name,
+                                   const Object& resource,
+                                   size_t queue_size = 1);
+  virtual ~AsyncProgressWorkerBase();
+
+// Optional callback of Napi::ThreadSafeFunction only available after
+// NAPI_VERSION 4. Refs: https://github.com/nodejs/node/pull/27791
+#if NAPI_VERSION > 4
+  explicit AsyncProgressWorkerBase(Napi::Env env,
+                                   const char* resource_name,
+                                   const Object& resource,
+                                   size_t queue_size = 1);
+#endif
+
+  static inline void OnAsyncWorkProgress(Napi::Env env,
+                                         Napi::Function jsCallback,
+                                         void* data);
+
+  napi_status NonBlockingCall(DataType* data);
+
+ private:
+  ThreadSafeFunction _tsfn;
+  bool _work_completed = false;
+  napi_status _complete_status;
+  static inline void OnThreadSafeFunctionFinalize(
+      Napi::Env env, void* data, AsyncProgressWorkerBase* context);
+};
+
+template <class T>
+class AsyncProgressWorker : public AsyncProgressWorkerBase<void> {
+ public:
+  virtual ~AsyncProgressWorker();
+
+  class ExecutionProgress {
+    friend class AsyncProgressWorker;
+
+   public:
+    void Signal() const;
+    void Send(const T* data, size_t count) const;
+
+   private:
+    explicit ExecutionProgress(AsyncProgressWorker* worker) : _worker(worker) {}
+    AsyncProgressWorker* const _worker;
+  };
+
+  void OnWorkProgress(void*) override;
+
+ protected:
+  explicit AsyncProgressWorker(const Function& callback);
+  explicit AsyncProgressWorker(const Function& callback,
+                               const char* resource_name);
+  explicit AsyncProgressWorker(const Function& callback,
+                               const char* resource_name,
+                               const Object& resource);
+  explicit AsyncProgressWorker(const Object& receiver,
+                               const Function& callback);
+  explicit AsyncProgressWorker(const Object& receiver,
+                               const Function& callback,
+                               const char* resource_name);
+  explicit AsyncProgressWorker(const Object& receiver,
+                               const Function& callback,
+                               const char* resource_name,
+                               const Object& resource);
+
+// Optional callback of Napi::ThreadSafeFunction only available after
+// NAPI_VERSION 4. Refs: https://github.com/nodejs/node/pull/27791
+#if NAPI_VERSION > 4
+  explicit AsyncProgressWorker(Napi::Env env);
+  explicit AsyncProgressWorker(Napi::Env env, const char* resource_name);
+  explicit AsyncProgressWorker(Napi::Env env,
+                               const char* resource_name,
+                               const Object& resource);
+#endif
+  virtual void Execute(const ExecutionProgress& progress) = 0;
+  virtual void OnProgress(const T* data, size_t count) = 0;
+
+ private:
+  void Execute() override;
+  void Signal();
+  void SendProgress_(const T* data, size_t count);
+
+  std::mutex _mutex;
+  T* _asyncdata;
+  size_t _asyncsize;
+  bool _signaled;
+};
+
+template <class T>
+class AsyncProgressQueueWorker
+    : public AsyncProgressWorkerBase<std::pair<T*, size_t>> {
+ public:
+  virtual ~AsyncProgressQueueWorker(){};
+
+  class ExecutionProgress {
+    friend class AsyncProgressQueueWorker;
+
+   public:
+    void Signal() const;
+    void Send(const T* data, size_t count) const;
+
+   private:
+    explicit ExecutionProgress(AsyncProgressQueueWorker* worker)
+        : _worker(worker) {}
+    AsyncProgressQueueWorker* const _worker;
+  };
+
+  void OnWorkComplete(Napi::Env env, napi_status status) override;
+  void OnWorkProgress(std::pair<T*, size_t>*) override;
+
+ protected:
+  explicit AsyncProgressQueueWorker(const Function& callback);
+  explicit AsyncProgressQueueWorker(const Function& callback,
+                                    const char* resource_name);
+  explicit AsyncProgressQueueWorker(const Function& callback,
+                                    const char* resource_name,
+                                    const Object& resource);
+  explicit AsyncProgressQueueWorker(const Object& receiver,
+                                    const Function& callback);
+  explicit AsyncProgressQueueWorker(const Object& receiver,
+                                    const Function& callback,
+                                    const char* resource_name);
+  explicit AsyncProgressQueueWorker(const Object& receiver,
+                                    const Function& callback,
+                                    const char* resource_name,
+                                    const Object& resource);
+
+// Optional callback of Napi::ThreadSafeFunction only available after
+// NAPI_VERSION 4. Refs: https://github.com/nodejs/node/pull/27791
+#if NAPI_VERSION > 4
+  explicit AsyncProgressQueueWorker(Napi::Env env);
+  explicit AsyncProgressQueueWorker(Napi::Env env, const char* resource_name);
+  explicit AsyncProgressQueueWorker(Napi::Env env,
+                                    const char* resource_name,
+                                    const Object& resource);
+#endif
+  virtual void Execute(const ExecutionProgress& progress) = 0;
+  virtual void OnProgress(const T* data, size_t count) = 0;
+
+ private:
+  void Execute() override;
+  void Signal() const;
+  void SendProgress_(const T* data, size_t count);
+};
+#endif  // NAPI_VERSION > 3 && NAPI_HAS_THREADS
+
+// Memory management.
+class MemoryManagement {
+ public:
+  static int64_t AdjustExternalMemory(Env env, int64_t change_in_bytes);
+};
+
+// Version management
+class VersionManagement {
+ public:
+  static uint32_t GetNapiVersion(Env env);
+  static const napi_node_version* GetNodeVersion(Env env);
+};
+
+#if NAPI_VERSION > 5
+template <typename T>
+class Addon : public InstanceWrap<T> {
+ public:
+  static inline Object Init(Env env, Object exports);
+  static T* Unwrap(Object wrapper);
+
+ protected:
+  using AddonProp = ClassPropertyDescriptor<T>;
+  void DefineAddon(Object exports,
+                   const std::initializer_list<AddonProp>& props);
+  Napi::Object DefineProperties(Object object,
+                                const std::initializer_list<AddonProp>& props);
+
+ private:
+  Object entry_point_;
+};
+#endif  // NAPI_VERSION > 5
+
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+}  // namespace NAPI_CPP_CUSTOM_NAMESPACE
+#endif
+
+}  // namespace Napi
+
+// Inline implementations of all the above class methods are included here.
+#include "napi-inl.h"
+
+#endif  // SRC_NAPI_H_
