nan: add support for JSON::Parse & Stringify (#651)

* nan: add support for JSON::Parse & Stringify Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: entry points need a Nan::HandleScope Add a Nan::HandleScope to each static entry point. The private singleton class constructor does not need a Nan::HandleScope, because it can only be called from one of the static entry points. Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: ditch the singleton and remove all persistence Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: we *always* need a HandleScope Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: use Nan::To<v8::String> rather than ->ToString() Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: use Nan::Get rather than v8::Object::Get Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: use Nan::To<v8::Object> rather than ->ToObject() Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: proper HandleScope placement for Parse() Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * doc/json.md: Nan::To<v8::Object> returns a MaybeLocal<v8::Object> Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: dont call ToLocalChecked on an empty MaybeLocal Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: replace v8::MaybeLocal with Nan::MaybeLocal Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: check MaybeLocal returned by Nan::To<v8::Object> Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * remove rvagg from notifications * nan_json.h: replace v8::MaybeLocal with Nan::MaybeLocal Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * convert Nan::JSON to an RAII class Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: all entry points need a Nan::EscapableHandleScope Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: v8::JSON::Parse() that takes no context returns v8::Local<v8::Value> Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: check !Nan::Callback.IsEmpty() before calling it Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * Revert "remove rvagg from notifications" This reverts commit 00a98ec. * nan_json.h: rename for consistency: jsonObject->json_object, jsonString->json_string Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-parse.cpp: fix memory leak Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: rename m_cb_parse->parse_cb_ & m_cb_stringify->stringify_cb_ Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: remove unnecessary destructor Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: identify the #endif's Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: rename parseMethod->parse_method & stringifyMethod->stringify_method Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: use Local<Value>.As<Function> rather than Local<Function>::Cast Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: convert camelCase locals to snake_case Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: remove parens from precompiler directives Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: check NODE_MODULE_VERSION rather than NODE_MAJOR_VERSION & NODE_MINOR_VERSION Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * doc/json.md: check MaybeLocal before extraction Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * doc/json.md: clean up 'Use JSON.Api(arg) to ...' short description Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * doc/json.md: Nan::JSON.[Api] instead of Nan::JSON::[Api] Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-parse.cpp: check MaybeLocal before proceeding Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-stringify.cpp: improve argument checks Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/strings.cpp: check MaybeLocal before proceeding Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-*.cpp: return Nan::Undefined() in the MaybeLocal.IsEmpty() case Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/js/json-parse-test.js: add more test cases Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/js/json-stringify-test.js: add more test cases Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/js/json-parse-test.js: add spaces near square brackets in arrays Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-stringify.cpp: check gap argument before extraction Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-stringify.cpp: replace v8::MaybeLocal with Nan::MaybeLocal Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: JSON constructor needs a Nan::HandleScope Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-*.cpp: prefer the fast primitive setters where available replace ReturnValue::Set(Nan::Undefined()) with ReturnValue::SetUndefined() Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: add assertions to constructor sanity checks Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: convert remaining sanity checks to assertions Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * test/cpp/json-*.cpp: no need to set return value to Undefined as it is the default Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com> * nan_json.h: remove superfluous newlines after assert Signed-off-by: Michael Ira Krufky <mkrufky@gmail.com>
nodejs · Apr 4, 2017 · b533226 · b533226
1 parent 5b7083b
commit b533226
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Showing 12 changed files with 479 additions and 3 deletions.
diff --git a/Makefile b/Makefile
@@ -23,6 +23,7 @@ LINT_SOURCES = \
 	nan_converters_pre_43_inl.h \
 	nan_implementation_12_inl.h \
 	nan_implementation_pre_12_inl.h \
+	nan_json.h \
 	nan_maybe_43_inl.h \
 	nan_maybe_pre_43_inl.h \
 	nan_new.h \
@@ -46,6 +47,8 @@ LINT_SOURCES = \
 	test/cpp/indexedinterceptors.cpp \
 	test/cpp/converters.cpp \
 	test/cpp/isolatedata.cpp \
+	test/cpp/json-parse.cpp \
+	test/cpp/json-stringify.cpp \
 	test/cpp/makecallback.cpp \
 	test/cpp/morenews.cpp \
 	test/cpp/multifile1.cpp \
@@ -90,14 +93,14 @@ forcetest:
 docs: README.md doc/.build.sh doc/asyncworker.md doc/buffers.md doc/callback.md \
 		doc/converters.md doc/errors.md doc/maybe_types.md doc/methods.md doc/new.md \
 		doc/node_misc.md doc/persistent.md doc/scopes.md doc/script.md doc/string_bytes.md \
-		doc/v8_internals.md doc/v8_misc.md
+		doc/v8_internals.md doc/json.md doc/v8_misc.md
 	doc/.build.sh
 
 
 $(ADDONS): nan.h nan_new.h nan_implementation_pre_12_inl.h nan_implementation_12_inl.h \
 		nan_callbacks.h nan_callbacks_12_inl.h nan_callbacks_pre_12_inl.h \
 		nan_converters.h nan_converters_43_inl.h nan_converters_pre_43_inl.h \
-		nan_maybe_43_inl.h nan_maybe_pre_43_inl.h \
+		nan_json.h nan_maybe_43_inl.h nan_maybe_pre_43_inl.h \
 		nan_persistent_12_inl.h nan_persistent_pre_12_inl.h nan_private.h \
 		nan_weak.h nan_string_bytes.h test/binding.gyp $(SOURCES)
 	cd test/ && ../node_modules/.bin/node-gyp rebuild
diff --git a/README.md b/README.md
@@ -210,6 +210,15 @@ NAN provides a `v8::Script` helpers as the API has changed over the supported ve
  - <a href="doc/script.md#api_nan_run_script"><b><code>Nan::RunScript()</code></b></a>
 
 
+### JSON
+
+The _JSON_ object provides the c++ versions of the methods offered by the `JSON` object in javascript. V8 exposes these methods via the `v8::JSON` object.
+
+ - <a href="doc/json.md#api_nan_json_parse"><b><code>Nan::JSON.Parse</code></b></a>
+ - <a href="doc/json.md#api_nan_json_stringify"><b><code>Nan::JSON.Stringify</code></b></a>
+
+Refer to the V8 JSON object in the [V8 documentation](https://v8docs.nodesource.com/node-7.4/da/d6f/classv8_1_1_j_s_o_n.html) for more information about these methods and their arguments.
+
 ### Errors
 
 NAN includes helpers for creating, throwing and catching Errors as much of this functionality varies across the supported versions of V8 and must be abstracted.

diff --git a/doc/.build.sh b/doc/.build.sh
@@ -8,6 +8,7 @@ files="              \
   converters.md      \
   maybe_types.md     \
   script.md          \
+  json.md            \
   errors.md          \
   buffers.md         \
   callback.md        \

diff --git a/doc/json.md b/doc/json.md
@@ -0,0 +1,62 @@
+## JSON
+
+The _JSON_ object provides the c++ versions of the methods offered by the `JSON` object in javascript. V8 exposes these methods via the `v8::JSON` object.
+
+ - <a href="#api_nan_json_parse"><b><code>Nan::JSON.Parse</code></b></a>
+ - <a href="#api_nan_json_stringify"><b><code>Nan::JSON.Stringify</code></b></a>
+
+Refer to the V8 JSON object in the [V8 documentation](https://v8docs.nodesource.com/node-7.4/da/d6f/classv8_1_1_j_s_o_n.html) for more information about these methods and their arguments.
+
+<a name="api_nan_json_parse"></a>
+
+### Nan::JSON.Parse
+
+A simple wrapper around [`v8::JSON::Parse`](https://v8docs.nodesource.com/node-7.4/da/d6f/classv8_1_1_j_s_o_n.html#a936310d2540fb630ed37d3ee3ffe4504).
+
+Definition:
+
+```c++
+Nan::MaybeLocal<v8::Value> Nan::JSON::Parse(v8::Local<v8::String> json_string);
+```
+
+Use `JSON.Parse(json_string)` to parse a string into a `v8::Value`.
+
+Example:
+
+```c++
+v8::Local<v8::String> json_string = Nan::New("{ \"JSON\": \"object\" }").ToLocalChecked();
+
+Nan::JSON NanJSON;
+Nan::MaybeLocal<v8::Value> result = NanJSON.Parse(json_string);
+if (!result.IsEmpty()) {
+  v8::Local<v8::Value> val = result.ToLocalChecked();
+}
+```
+
+<a name="api_nan_json_stringify"></a>
+
+### Nan::JSON.Stringify
+
+A simple wrapper around [`v8::JSON::Stringify`](https://v8docs.nodesource.com/node-7.4/da/d6f/classv8_1_1_j_s_o_n.html#a44b255c3531489ce43f6110209138860).
+
+Definition:
+
+```c++
+Nan::MaybeLocal<v8::String> Nan::JSON::Stringify(v8::Local<v8::Object> json_object, v8::Local<v8::String> gap = v8::Local<v8::String>());
+```
+
+Use `JSON.Stringify(value)` to stringify a `v8::Object`.
+
+Example:
+
+```c++
+// using `v8::Local<v8::Value> val` from the `JSON::Parse` example
+v8::Local<v8::Object> obj = Nan::To<v8::Object>(val).ToLocalChecked();
+
+Nan::JSON NanJSON;
+Nan::MaybeLocal<v8::String> result = NanJSON.Stringify(obj);
+if (!result.IsEmpty()) {
+  v8::Local<v8::String> stringified = result.ToLocalChecked();
+}
+```
+
diff --git a/nan.h b/nan.h
@@ -2310,6 +2310,10 @@ MakeMaybe(MaybeMaybe<T> v) {
 
 #include "nan_typedarray_contents.h"  // NOLINT(build/include)
 
+//=== JSON =====================================================================
+
+#include "nan_json.h"  // NOLINT(build/include)
+
 }  // end of namespace Nan
 
 #endif  // NAN_H_
diff --git a/nan_json.h b/nan_json.h
@@ -0,0 +1,155 @@
+/*********************************************************************
+ * NAN - Native Abstractions for Node.js
+ *
+ * Copyright (c) 2017 NAN contributors
+ *
+ * MIT License <https://github.com/nodejs/nan/blob/master/LICENSE.md>
+ ********************************************************************/
+
+#ifndef NAN_JSON_H_
+#define NAN_JSON_H_
+
+#if NODE_MODULE_VERSION < NODE_0_12_MODULE_VERSION
+#define NAN_JSON_H_NEED_PARSE 1
+#else
+#define NAN_JSON_H_NEED_PARSE 0
+#endif  // NODE_MODULE_VERSION < NODE_0_12_MODULE_VERSION
+
+#if NODE_MODULE_VERSION > NODE_6_0_MODULE_VERSION
+#define NAN_JSON_H_NEED_STRINGIFY 0
+#else
+#define NAN_JSON_H_NEED_STRINGIFY 1
+#endif  // NODE_MODULE_VERSION > NODE_6_0_MODULE_VERSION
+
+class JSON {
+ public:
+  JSON() {
+#if NAN_JSON_H_NEED_PARSE + NAN_JSON_H_NEED_STRINGIFY
+    Nan::HandleScope scope;
+
+    Nan::MaybeLocal<v8::Value> maybe_global_json = Nan::Get(
+      Nan::GetCurrentContext()->Global(),
+      Nan::New("JSON").ToLocalChecked()
+    );
+
+    assert(!maybe_global_json.IsEmpty() && "global JSON is empty");
+    v8::Local<v8::Value> val_global_json = maybe_global_json.ToLocalChecked();
+
+    assert(val_global_json->IsObject() && "global JSON is not an object");
+    Nan::MaybeLocal<v8::Object> maybe_obj_global_json =
+      Nan::To<v8::Object>(val_global_json);
+
+    assert(!maybe_obj_global_json.IsEmpty() && "global JSON object is empty");
+    v8::Local<v8::Object> global_json = maybe_obj_global_json.ToLocalChecked();
+
+#if NAN_JSON_H_NEED_PARSE
+    Nan::MaybeLocal<v8::Value> maybe_parse_method = Nan::Get(
+      global_json, Nan::New("parse").ToLocalChecked()
+    );
+
+    assert(!maybe_parse_method.IsEmpty() && "JSON.parse is empty");
+    v8::Local<v8::Value> parse_method = maybe_parse_method.ToLocalChecked();
+
+    assert(parse_method->IsFunction() && "JSON.parse is not a function");
+    parse_cb_.Reset(parse_method.As<v8::Function>());
+#endif  // NAN_JSON_H_NEED_PARSE
+
+#if NAN_JSON_H_NEED_STRINGIFY
+    Nan::MaybeLocal<v8::Value> maybe_stringify_method = Nan::Get(
+      global_json, Nan::New("stringify").ToLocalChecked()
+    );
+
+    assert(!maybe_stringify_method.IsEmpty() && "JSON.stringify is empty");
+    v8::Local<v8::Value> stringify_method =
+      maybe_stringify_method.ToLocalChecked();
+
+    assert(
+      stringify_method->IsFunction() && "JSON.stringify is not a function"
+    );
+    stringify_cb_.Reset(stringify_method.As<v8::Function>());
+#endif  // NAN_JSON_H_NEED_STRINGIFY
+#endif  // NAN_JSON_H_NEED_PARSE + NAN_JSON_H_NEED_STRINGIFY
+  }
+
+  inline
+  Nan::MaybeLocal<v8::Value> Parse(v8::Local<v8::String> json_string) {
+    Nan::EscapableHandleScope scope;
+#if NAN_JSON_H_NEED_PARSE
+    return scope.Escape(parse(json_string));
+#else
+#if NODE_MODULE_VERSION > NODE_6_0_MODULE_VERSION
+    Nan::MaybeLocal<v8::Value> result =
+      v8::JSON::Parse(Nan::GetCurrentContext(), json_string);
+
+    if (result.IsEmpty()) return v8::Local<v8::Value>();
+    return scope.Escape(result.ToLocalChecked());
+#else
+    return scope.Escape(v8::JSON::Parse(json_string));
+#endif  // NODE_MODULE_VERSION > NODE_6_0_MODULE_VERSION
+#endif  // NAN_JSON_H_NEED_PARSE
+  }
+
+  inline
+  Nan::MaybeLocal<v8::String> Stringify(v8::Local<v8::Object> json_object) {
+    Nan::EscapableHandleScope scope;
+    Nan::MaybeLocal<v8::String> result =
+#if NAN_JSON_H_NEED_STRINGIFY
+      Nan::To<v8::String>(stringify(json_object));
+#else
+      v8::JSON::Stringify(Nan::GetCurrentContext(), json_object);
+#endif  // NAN_JSON_H_NEED_STRINGIFY
+    if (result.IsEmpty()) return v8::Local<v8::String>();
+    return scope.Escape(result.ToLocalChecked());
+  }
+
+  inline
+  Nan::MaybeLocal<v8::String> Stringify(v8::Local<v8::Object> json_object,
+    v8::Local<v8::String> gap) {
+    Nan::EscapableHandleScope scope;
+    Nan::MaybeLocal<v8::String> result =
+#if NAN_JSON_H_NEED_STRINGIFY
+      Nan::To<v8::String>(stringify(json_object, gap));
+#else
+      v8::JSON::Stringify(Nan::GetCurrentContext(), json_object, gap);
+#endif  // NAN_JSON_H_NEED_STRINGIFY
+    if (result.IsEmpty()) return v8::Local<v8::String>();
+    return scope.Escape(result.ToLocalChecked());
+  }
+
+ private:
+  NAN_DISALLOW_ASSIGN_COPY_MOVE(JSON)
+#if NAN_JSON_H_NEED_PARSE
+  Nan::Callback parse_cb_;
+#endif  // NAN_JSON_H_NEED_PARSE
+#if NAN_JSON_H_NEED_STRINGIFY
+  Nan::Callback stringify_cb_;
+#endif  // NAN_JSON_H_NEED_STRINGIFY
+
+#if NAN_JSON_H_NEED_PARSE
+  inline v8::Local<v8::Value> parse(v8::Local<v8::Value> arg) {
+    assert(!parse_cb_.IsEmpty() && "parse_cb_ is empty");
+    return parse_cb_.Call(1, &arg);
+  }
+#endif  // NAN_JSON_H_NEED_PARSE
+
+#if NAN_JSON_H_NEED_STRINGIFY
+  inline v8::Local<v8::Value> stringify(v8::Local<v8::Value> arg) {
+    assert(!stringify_cb_.IsEmpty() && "stringify_cb_ is empty");
+    return stringify_cb_.Call(1, &arg);
+  }
+
+  inline v8::Local<v8::Value> stringify(v8::Local<v8::Value> arg,
+    v8::Local<v8::String> gap) {
+    assert(!stringify_cb_.IsEmpty() && "stringify_cb_ is empty");
+
+    v8::Local<v8::Value> argv[] = {
+      arg,
+      Nan::Null(),
+      gap
+    };
+    return stringify_cb_.Call(3, argv);
+  }
+#endif  // NAN_JSON_H_NEED_STRINGIFY
+};
+
+#endif  // NAN_JSON_H_
diff --git a/package.json b/package.json
@@ -19,7 +19,8 @@
     "Nathan Rajlich <nathan@tootallnate.net> (https://github.com/TooTallNate)",
     "Brett Lawson <brett19@gmail.com> (https://github.com/brett19)",
     "Ben Noordhuis <info@bnoordhuis.nl> (https://github.com/bnoordhuis)",
-    "David Siegel <david@artcom.de> (https://github.com/agnat)"
+    "David Siegel <david@artcom.de> (https://github.com/agnat)",
+    "Michael Ira Krufky <mkrufky@gmail.com> (https://github.com/mkrufky)"
   ],
   "devDependencies": {
     "bindings": "~1.2.1",

diff --git a/test/binding.gyp b/test/binding.gyp
@@ -156,4 +156,12 @@
         "target_name" : "private"
       , "sources"     : [ "cpp/private.cpp" ]
     }
+    , {
+        "target_name" : "parse"
+      , "sources"     : [ "cpp/json-parse.cpp" ]
+    }
+    , {
+        "target_name" : "stringify"
+      , "sources"     : [ "cpp/json-stringify.cpp" ]
+    }
 ]}
diff --git a/test/cpp/json-parse.cpp b/test/cpp/json-parse.cpp
@@ -0,0 +1,34 @@
+/*********************************************************************
+ * NAN - Native Abstractions for Node.js
+ *
+ * Copyright (c) 2017 NAN contributors
+ *
+ * MIT License <https://github.com/nodejs/nan/blob/master/LICENSE.md>
+ ********************************************************************/
+
+#include <nan.h>
+
+NAN_METHOD(Parse) {
+  Nan::JSON NanJSON;
+
+  Nan::MaybeLocal<v8::String> inp = Nan::To<v8::String>(info[0]);
+
+  if (!inp.IsEmpty()) {
+    Nan::MaybeLocal<v8::Value> result = NanJSON.Parse(
+      inp.ToLocalChecked()
+    );
+
+    if (!result.IsEmpty()) {
+      info.GetReturnValue().Set(result.ToLocalChecked());
+    }
+  }
+}
+
+NAN_MODULE_INIT(Init) {
+  Nan::Set(target
+    , Nan::New<v8::String>("parse").ToLocalChecked()
+    , Nan::New<v8::FunctionTemplate>(Parse)->GetFunction()
+  );
+}
+
+NODE_MODULE(parse, Init)