fix: avoid using deprecated Nan APIs

Starting with Nan 2.9.x certain Nan::Callback::Call APIs are
deprecated. Instead there are mechanisms in place that allow native
modules to preserve async context across async calls.

packages/grpc-native-core/ext/call.cc

@@ -446,13 +446,18 @@ class ServerCloseResponseOp : public Op {
 };
 
 tag::tag(Callback *callback, OpVec *ops, Call *call, Local<Value> call_value)
-    : callback(callback), ops(ops), call(call) {
+    : callback(callback),
+      async_resource(NULL),
+      ops(ops),
+      call(call) {
   HandleScope scope;
+  async_resource = new Nan::AsyncResource("grpc:tag");  // Needs handle scope.
   call_persist.Reset(call_value);
 }
 
 tag::~tag() {
   delete callback;
+  delete async_resource;
   delete ops;
 }
 
@@ -468,10 +473,10 @@ void CompleteTag(void *tag, const char *error_message) {
       Nan::Set(tag_obj, op_ptr->GetOpType(), op_ptr->GetNodeValue());
     }
     Local<Value> argv[] = {Nan::Null(), tag_obj};
-    callback->Call(2, argv);
+    callback->Call(2, argv, tag_struct->async_resource);
   } else {
     Local<Value> argv[] = {Nan::Error(error_message)};
-    callback->Call(1, argv);
+    callback->Call(1, argv, tag_struct->async_resource);
   }
   bool success = (error_message == NULL);
   bool is_final_op = false;

packages/grpc-native-core/ext/call.h

@@ -103,6 +103,7 @@ struct tag {
       v8::Local<v8::Value> call_value);
   ~tag();
   Nan::Callback *callback;
+  Nan::AsyncResource *async_resource;
   OpVec *ops;
   Call *call;
   Nan::Persistent<v8::Value, Nan::CopyablePersistentTraits<v8::Value>>

packages/grpc-native-core/ext/call_credentials.cc

@@ -233,7 +233,7 @@ NAUV_WORK_CB(SendPluginCallback) {
         // Get Local<Function> from Nan::Callback*
         **plugin_callback};
     Nan::Callback *callback = state->callback;
-    callback->Call(argc, argv);
+    callback->Call(argc, argv, data->async_resource);
     delete data;
   }
 }
@@ -245,11 +245,10 @@ int plugin_get_metadata(
     grpc_metadata creds_md[GRPC_METADATA_CREDENTIALS_PLUGIN_SYNC_MAX],
     size_t *num_creds_md, grpc_status_code *status,
     const char **error_details) {
+  HandleScope scope;
   plugin_state *p_state = reinterpret_cast<plugin_state *>(state);
-  plugin_callback_data *data = new plugin_callback_data;
-  data->service_url = context.service_url;
-  data->cb = cb;
-  data->user_data = user_data;
+  plugin_callback_data *data =
+      new plugin_callback_data(context.service_url, cb, user_data);
 
   uv_mutex_lock(&p_state->plugin_mutex);
   p_state->pending_callbacks->push(data);

packages/grpc-native-core/ext/call_credentials.h

@@ -62,9 +62,24 @@ class CallCredentials : public Nan::ObjectWrap {
 /* Auth metadata plugin functionality */
 
 typedef struct plugin_callback_data {
+  plugin_callback_data(const char *service_url_,
+                       grpc_credentials_plugin_metadata_cb cb_,
+                       void *user_data_)
+      : service_url(service_url_),
+        cb(cb_),
+        user_data(user_data_),
+        async_resource(NULL) {
+    Nan::HandleScope scope;
+    async_resource = new Nan::AsyncResource("grpc:plugin_callback_data");
+  }
+  ~plugin_callback_data() {
+    delete async_resource;
+  }
+
   const char *service_url;
   grpc_credentials_plugin_metadata_cb cb;
   void *user_data;
+  Nan::AsyncResource *async_resource;
 } plugin_callback_data;
 
 typedef struct plugin_state {

packages/grpc-native-core/ext/node_grpc.cc

@@ -57,6 +57,7 @@ typedef struct log_args {
 
 typedef struct logger_state {
   Nan::Callback *callback;
+  Nan::AsyncResource *async_resource;
   std::queue<log_args *> *pending_args;
   uv_mutex_t mutex;
   uv_async_t async;
@@ -202,7 +203,7 @@ NAUV_WORK_CB(LogMessagesCallback) {
             .ToLocalChecked();
     const int argc = 5;
     Local<Value> argv[argc] = {file, line, severity, message, timestamp};
-    grpc_logger_state.callback->Call(argc, argv);
+    grpc_logger_state.callback->Call(argc, argv, grpc_logger_state.async_resource);
     delete[] arg->core_args.message;
     delete arg;
   }
@@ -252,6 +253,7 @@ NAN_METHOD(SetDefaultLoggerCallback) {
     grpc_logger_state.logger_set = true;
   }
   grpc_logger_state.callback = new Nan::Callback(info[0].As<v8::Function>());
+  grpc_logger_state.async_resource = new Nan::AsyncResource("grpc:logger");
 }
 
 NAN_METHOD(SetLogVerbosity) {

packages/grpc-native-core/package.json

@@ -29,7 +29,7 @@
   ],
   "dependencies": {
     "lodash": "^4.15.0",
-    "nan": "^2.0.0",
+    "nan": "^2.10.0",
     "node-pre-gyp": "0.7.0",
     "protobufjs": "^5.0.0"
   },