From b180f18b7eaabe066c79b1b60043e3b593a25adb Mon Sep 17 00:00:00 2001
From: Samuel Attard <sattard@atlassian.com>
Date: Wed, 28 Mar 2018 11:32:10 +1100
Subject: [PATCH] Add mate::Promise

---
 native_mate/dictionary.cc |  2 +-
 native_mate/promise.cc    | 45 +++++++++++++++++++++++++++++++
 native_mate/promise.h     | 57 +++++++++++++++++++++++++++++++++++++++
 native_mate_files.gypi    |  2 ++
 4 files changed, 105 insertions(+), 1 deletion(-)
 create mode 100644 native_mate/promise.cc
 create mode 100644 native_mate/promise.h

diff --git a/native_mate/dictionary.cc b/native_mate/dictionary.cc
index b63acaf5b77..3caff114597 100644
--- a/native_mate/dictionary.cc
+++ b/native_mate/dictionary.cc
@@ -20,7 +20,7 @@ Dictionary::~Dictionary() {
 }
 
 Dictionary Dictionary::CreateEmpty(v8::Isolate* isolate) {
-  return Dictionary(isolate, v8::Object::New(isolate));;
+  return Dictionary(isolate, v8::Object::New(isolate));
 }
 
 v8::Local<v8::Object> Dictionary::GetHandle() const {
diff --git a/native_mate/promise.cc b/native_mate/promise.cc
new file mode 100644
index 00000000000..81b79441e72
--- /dev/null
+++ b/native_mate/promise.cc
@@ -0,0 +1,45 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "native_mate/promise.h"
+
+namespace mate {
+
+Promise::Promise()
+    : isolate_(NULL) {
+}
+
+Promise::Promise(v8::Isolate* isolate)
+    : isolate_(isolate) {
+  resolver_ = v8::Promise::Resolver::New(isolate);
+}
+
+Promise::~Promise() {
+}
+
+Promise Promise::Create(v8::Isolate* isolate) {
+  return Promise(isolate);
+}
+
+Promise Promise::Create() {
+  return Promise::Create(v8::Isolate::GetCurrent());
+}
+
+void Promise::RejectWithErrorMessage(const std::string& string) {
+  v8::Local<v8::String> error_message =
+      v8::String::NewFromUtf8(isolate(), string.c_str());
+  v8::Local<v8::Value> error = v8::Exception::Error(error_message);
+  resolver_->Reject(mate::ConvertToV8(isolate(), error));
+}
+
+v8::Local<v8::Object> Promise::GetHandle() const {
+  return resolver_->GetPromise();
+}
+
+v8::Local<v8::Value> Converter<Promise>::ToV8(v8::Isolate* isolate,
+                                                  Promise val) {
+  return val.GetHandle();
+}
+
+}  // namespace mate
diff --git a/native_mate/promise.h b/native_mate/promise.h
new file mode 100644
index 00000000000..225ac6d048f
--- /dev/null
+++ b/native_mate/promise.h
@@ -0,0 +1,57 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef NATIVE_MATE_PROMISE_H_
+#define NATIVE_MATE_PROMISE_H_
+
+#include "native_mate/converter.h"
+
+namespace mate {
+
+class Promise {
+ public:
+  Promise();
+  Promise(v8::Isolate* isolate);
+  virtual ~Promise();
+
+  static Promise Create(v8::Isolate* isolate);
+  static Promise Create();
+
+  v8::Isolate* isolate() const { return isolate_; }
+
+  virtual v8::Local<v8::Object> GetHandle() const;
+
+  template<typename T>
+  void Resolve(T* value) {
+    resolver_->Resolve(mate::ConvertToV8(isolate(), value));
+  }
+
+  template<typename T>
+  void Reject(T* value) {
+    resolver_->Reject(mate::ConvertToV8(isolate(), value));
+  }
+
+  void RejectWithErrorMessage(const std::string& error);
+
+ protected:
+  v8::Isolate* isolate_;
+
+ private:
+  v8::Local<v8::Promise::Resolver> resolver_;
+};
+
+template<>
+struct Converter<Promise> {
+  static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
+                                    Promise val);
+  // TODO(MarshallOfSound): Implement FromV8 to allow promise chaining
+  //                        in native land
+  // static bool FromV8(v8::Isolate* isolate,
+  //                    v8::Local<v8::Value> val,
+  //                    Promise* out);
+};
+
+}  // namespace mate
+
+#endif  // NATIVE_MATE_PROMISE_H_
diff --git a/native_mate_files.gypi b/native_mate_files.gypi
index 867ec7999c8..bf10470d02a 100644
--- a/native_mate_files.gypi
+++ b/native_mate_files.gypi
@@ -22,6 +22,8 @@
       'native_mate/wrappable.cc',
       'native_mate/wrappable.h',
       'native_mate/wrappable_base.h',
+      'native_mate/promise.h',
+      'native_mate/promise.cc',
     ],
   },
 }