Add Date::New overload for a std::chrono::system_clock::time_point

napi-inl.h

@@ -20,6 +20,9 @@
 #endif  // NAPI_HAS_THREADS
 #include <type_traits>
 #include <utility>
+#if __cplusplus >= 201103L
+#include <chrono>
+#endif
 
 #if defined(__clang__) || defined(__GNUC__)
 #define NAPI_NO_SANITIZE_VPTR __attribute__((no_sanitize("vptr")))
@@ -1199,6 +1202,15 @@ inline Date Date::New(napi_env env, double val) {
   return Date(env, value);
 }
 
+#if __cplusplus >= 201103L
+inline Date Date::New(napi_env env, std::chrono::system_clock::time_point tp) {
+  using namespace std::chrono;
+  auto ms = static_cast<double>(
+      duration_cast<milliseconds>(tp.time_since_epoch()).count());
+  return Date::New(env, ms);
+}
+#endif
+
 inline void Date::CheckCast(napi_env env, napi_value value) {
   NAPI_CHECK(value != nullptr, "Date::CheckCast", "empty value");
 

napi.h

@@ -19,6 +19,9 @@
 #endif  // NAPI_HAS_THREADS
 #include <string>
 #include <vector>
+#if __cplusplus >= 201103L
+#include <chrono>
+#endif
 
 // VS2015 RTM has bugs with constexpr, so require min of VS2015 Update 3 (known
 // good version)
@@ -685,6 +688,12 @@ class Date : public Value {
                   double value   ///< Number value
   );
 
+  /// Creates a new Date value from a std::chrono::system_clock::time_point.
+  static Date New(
+      napi_env env,                             ///< Node-API environment
+      std::chrono::system_clock::time_point tp  ///< Time point value
+  );
+
   static void CheckCast(napi_env env, napi_value value);
 
   Date();  ///< Creates a new _empty_ Date instance.

test/date.cc

@@ -1,3 +1,7 @@
+#if __cplusplus >= 201103L
+#include <chrono>
+#endif
+
 #include "napi.h"
 
 using namespace Napi;
@@ -11,6 +15,13 @@ Value CreateDate(const CallbackInfo& info) {
   return Date::New(info.Env(), input);
 }
 
+#if __cplusplus >= 201103L
+Value CreateDateFromTimePoint(const CallbackInfo& info) {
+  auto input = std::chrono::system_clock::time_point{};
+  return Date::New(info.Env(), input);
+}
+#endif
+
 Value IsDate(const CallbackInfo& info) {
   Date input = info[0].As<Date>();
 
@@ -35,6 +46,7 @@ Value OperatorValue(const CallbackInfo& info) {
 Object InitDate(Env env) {
   Object exports = Object::New(env);
   exports["CreateDate"] = Function::New(env, CreateDate);
+  exports["CreateDateFromTimePoint"] = Function::New(env, CreateDate);
   exports["IsDate"] = Function::New(env, IsDate);
   exports["ValueOf"] = Function::New(env, ValueOf);
   exports["OperatorValue"] = Function::New(env, OperatorValue);

test/date.js

@@ -12,6 +12,7 @@ function test (binding) {
     OperatorValue
   } = binding.date;
   assert.deepStrictEqual(CreateDate(0), new Date(0));
+  assert.deepStrictEqual(CreateDateFromTimePoint(), new Date(0));
   assert.strictEqual(IsDate(new Date(0)), true);
   assert.strictEqual(ValueOf(new Date(42)), 42);
   assert.strictEqual(OperatorValue(new Date(42)), true);