[WIP] Initial implemenation of nodejs support

Remaining issues:
* https://github.com/google/protobuf/issues/1591
  There's no way to unmarshal from JSON.

node/bin/greeter_client.js

@@ -0,0 +1,14 @@
+'use strict';
+
+const greeter = require('../src/client');
+
+async function main() {
+  const client = new greeter.GreeterClient('0.0.0.0:5000');
+  try {
+    console.log(await client.greet('a'));
+  } catch (err) {
+    console.error("Failed to call greeter: %s", err);
+  }
+}
+
+main();

node/bin/greeter_server.js

@@ -0,0 +1,16 @@
+'use strict';
+
+const greeter = require('../src/server');
+
+const grpc = require('grpc');
+
+function main() {
+  const server = new grpc.Server();
+  greeter.registerGreeterService(server);
+  server.bind('0.0.0.0:5000', grpc.ServerCredentials.createInsecure());
+
+  console.log(`listening on ${addr}`)
+  server.start();
+}
+
+main();

node/gulpfile.js

@@ -0,0 +1,16 @@
+"use strict";
+
+var gulp = require('gulp');
+var shell = require('gulp-shell');
+
+gulp.task('compile', function(){
+  return gulp.src('../greeter.proto')
+    .pipe(shell([
+      'protoc', '-I..',
+      '--js_out=import_style=commonjs,binary:proto',
+      '--grpc_out=import_style=commonjs,binary:proto',
+      '--plugin=protoc-gen-grpc=`which grpc_node_plugin`',
+      '../greeter.proto',
+    ].join(' ')))
+    .pipe(gulp.dest('proto'));
+})

node/package.json

@@ -5,8 +5,16 @@
   "main": "index.js",
   "repository": "https://github.com/yugui/grpc-custom-serializer",
   "author": "Yuki Yugui Sonoda",
-  "license": "Apache 2.0",
+  "license": "Apache-2.0",
   "dependencies": {
+    "google-protobuf": "^3.5.0",
     "grpc": "^1.9.1"
+  },
+  "devDependencies": {
+    "gulp": "^3.9.1",
+    "gulp-shell": "^0.6.5"
+  },
+  "scripts": {
+    "compile": "gulp compile"
   }
 }

node/proto/.gitignore

@@ -0,0 +1,2 @@
+*
+!/.gitignore

node/src/client.js

@@ -0,0 +1,40 @@
+'use strict';
+
+const messages = require('../proto/greeter_pb');
+const services = require('../proto/greeter_grpc_pb');
+
+const {promisify} = require('util');
+const grpc = require('grpc');
+
+/**
+ * Wrapper of the client stub of Greeter serivce.
+ */
+class GreeterClient {
+  constructor(addr) {
+    this.client = new services.GreeterClient(addr,
+      grpc.credentials.createInsecure());
+  }
+
+  /**
+   * @param {string} name - the name to greet to.
+   * @returns {Promise} Promise object represents the greeting message
+   *   from the server.
+   */
+  greet(name) {
+    const request = new messages.RequestProto();
+    request.setName(name);
+    return new Promise((resolve, reject) => {
+      this.client.greet(request, (err, response) => {
+        if (err) {
+          reject(err);
+          return;
+        }
+        resolve(response.getMessage());
+      });
+    });
+  }
+};
+
+module.exports = {
+  GreeterClient: GreeterClient,
+};

node/src/server.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const messages = require('../proto/greeter_pb');
+const services = require('../proto/greeter_grpc_pb');
+
+/**
+ * An implementation of Greeter service.
+ */
+class GreeterServer {
+  greet(call, callback) {
+    const response = new messages.ResponseProto();
+    response.setMessage(`Hello, ${call.request.getName()}`);
+    callback(null, response);
+  }
+};
+
+/**
+ * Registers an instance of GreeterServer to the given server.
+ * @param {grpc.Server} server - a grpc server.
+ */
+function registerGreeterService(server) {
+  server.addService(services.GreeterService, new GreeterServer());
+}
+
+module.exports = {
+  GreeterServer: GreeterServer,
+  registerGreeterService: registerGreeterService,
+};
+