util: determine object types in C++

Determine object types of regular expressions, Dates, Maps, and
Sets in the C++ layer instead of depending on toString()
behavior in JavaScript.

PR-URL: https://github.com/nodejs/node/pull/4100
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Michaël Zasso <mic.besace@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

lib/util.js

@@ -6,7 +6,6 @@ const internalUtil = require('internal/util');
 const binding = process.binding('util');
 
 const isError = internalUtil.isError;
-const objectToString = internalUtil.objectToString;
 
 var Debug;
 
@@ -312,7 +311,7 @@ function formatValue(ctx, value, recurseTimes) {
     braces = ['[', ']'];
     empty = value.length === 0;
     formatter = formatArray;
-  } else if (objectToString(value) === '[object Set]') {
+  } else if (binding.isSet(value)) {
     braces = ['{', '}'];
     // With `showHidden`, `length` will display as a hidden property for
     // arrays. For consistency's sake, do the same for `size`, even though this
@@ -321,7 +320,7 @@ function formatValue(ctx, value, recurseTimes) {
       keys.unshift('size');
     empty = value.size === 0;
     formatter = formatSet;
-  } else if (objectToString(value) === '[object Map]') {
+  } else if (binding.isMap(value)) {
     braces = ['{', '}'];
     // Ditto.
     if (ctx.showHidden)
@@ -719,7 +718,7 @@ function isUndefined(arg) {
 exports.isUndefined = isUndefined;
 
 function isRegExp(re) {
-  return objectToString(re) === '[object RegExp]';
+  return binding.isRegExp(re);
 }
 exports.isRegExp = isRegExp;
 
@@ -729,7 +728,7 @@ function isObject(arg) {
 exports.isObject = isObject;
 
 function isDate(d) {
-  return objectToString(d) === '[object Date]';
+  return binding.isDate(d);
 }
 exports.isDate = isDate;
 

src/node_util.cc

@@ -13,12 +13,37 @@ using v8::Object;
 using v8::String;
 using v8::Value;
 
+
+static void IsRegExp(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsRegExp());
+}
+
+
+static void IsDate(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsDate());
+}
+
+
+static void IsMap(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsMap());
+}
+
+
 static void IsMapIterator(const FunctionCallbackInfo<Value>& args) {
   CHECK_EQ(1, args.Length());
   args.GetReturnValue().Set(args[0]->IsMapIterator());
 }
 
 
+static void IsSet(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsSet());
+}
+
+
 static void IsSetIterator(const FunctionCallbackInfo<Value>& args) {
   CHECK_EQ(1, args.Length());
   args.GetReturnValue().Set(args[0]->IsSetIterator());
@@ -68,7 +93,11 @@ void Initialize(Local<Object> target,
                 Local<Value> unused,
                 Local<Context> context) {
   Environment* env = Environment::GetCurrent(context);
+  env->SetMethod(target, "isRegExp", IsRegExp);
+  env->SetMethod(target, "isDate", IsDate);
+  env->SetMethod(target, "isMap", IsMap);
   env->SetMethod(target, "isMapIterator", IsMapIterator);
+  env->SetMethod(target, "isSet", IsSet);
   env->SetMethod(target, "isSetIterator", IsSetIterator);
   env->SetMethod(target, "isPromise", IsPromise);
   env->SetMethod(target, "isTypedArray", IsTypedArray);