Add GCM sender

GCM.js

@@ -0,0 +1,80 @@
+var Parse = require('parse/node').Parse;
+var gcm = require('node-gcm');
+var randomstring = require('randomstring');
+
+var GCMTimeToLiveMax = 4 * 7 * 24 * 60 * 60; // GCM allows a max of 4 weeks
+var GCMRegistrationTokensMax = 1000;
+
+function GCM(apiKey) {
+  this.sender = new gcm.Sender(apiKey);
+}
+
+/**
+ * Send gcm request.
+ * @param {Object} data The data we need to send, the format is the same with api request body
+ * @param {Array} registrationTokens A array of registration tokens
+ * @returns {Object} A promise which is resolve after we get results from gcm
+ */
+GCM.prototype.send = function (data, registrationTokens) {
+  if (registrationTokens.length >= GCMRegistrationTokensMax) {
+    throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
+                          'Too many registration tokens for a GCM request.');
+  }
+  var pushId = randomstring.generate({
+    length: 10,
+    charset: 'alphanumeric'
+  });
+  var timeStamp = Date.now();
+  var expirationTime;
+  if (data['expiration_time']) {
+    expirationTime = data['expiration_time'];
+  }
+  // Generate gcm payload
+  var gcmPayload = generateGCMPayload(data.data, pushId, timeStamp, expirationTime);
+  // Make and send gcm request
+  var message = new gcm.Message(gcmPayload);
+  var promise = new Parse.Promise();
+  this.sender.send(message, { registrationTokens: registrationTokens }, 5, function (error, response) {
+    // TODO: Use the response from gcm to generate and save push report
+    // TODO: If gcm return some deviceTokens are invalid, set tombstone for the installation
+    promise.resolve();
+  });
+  return promise;
+}
+
+/**
+ * Generate the gcm payload from the data we get from api request.
+ * @param {Object} data The data field under api request body
+ * @param {String} pushId A random string
+ * @param {Number} timeStamp A number whose format is the Unix Epoch
+ * @param {Number|undefined} expirationTime A number whose format is the Unix Epoch or undefined
+ * @returns {Object} A promise which is resolved after we get results from gcm
+ */
+var generateGCMPayload = function(data, pushId, timeStamp, expirationTime) {
+  var payloadData =  {
+    'time': timeStamp,
+    'push_id': pushId,
+    'data': JSON.stringify(data)
+  }
+  var payload = {
+    priority: 'high',
+    data: payloadData
+  };
+  if (expirationTime) {
+   // The timeStamp and expiration is in milliseconds but gcm requires second
+    var timeToLive = Math.floor((expirationTime - timeStamp) / 1000);
+    if (timeToLive < 0) {
+      timeToLive = 0;
+    }
+    if (timeToLive >= GCMTimeToLiveMax) {
+      timeToLive = GCMTimeToLiveMax;
+    }
+    payload.timeToLive = timeToLive;
+  }
+  return payload;
+}
+
+if (typeof process !== 'undefined' && process.env.NODE_ENV === 'test') {
+  GCM.generateGCMPayload = generateGCMPayload;
+}
+module.exports = GCM;

package.json

@@ -19,6 +19,8 @@
     "mongodb": "~2.1.0",
     "multer": "^1.1.0",
     "parse": "^1.7.0",
+    "randomstring": "^1.1.3",
+    "node-gcm": "^0.14.0",
     "request": "^2.65.0"
   },
   "devDependencies": {

spec/GCM.spec.js

@@ -0,0 +1,133 @@
+var GCM = require('../GCM');
+
+describe('GCM', () => {
+  it('can generate GCM Payload without expiration time', (done) => {
+    //Mock request data
+    var data = {
+      'alert': 'alert'
+    };
+    var pushId = 1;
+    var timeStamp = 1454538822113;
+
+    var payload = GCM.generateGCMPayload(data, pushId, timeStamp);
+
+    expect(payload.priority).toEqual('high');
+    expect(payload.timeToLive).toEqual(undefined);
+    var dataFromPayload = payload.data;
+    expect(dataFromPayload.time).toEqual(timeStamp);
+    expect(dataFromPayload['push_id']).toEqual(pushId);
+    var dataFromUser = JSON.parse(dataFromPayload.data);
+    expect(dataFromUser).toEqual(data);
+    done();
+  });
+
+  it('can generate GCM Payload with valid expiration time', (done) => {
+    //Mock request data
+    var data = {
+      'alert': 'alert'
+    };
+    var pushId = 1;
+    var timeStamp = 1454538822113;
+    var expirationTime = 1454538922113
+
+    var payload = GCM.generateGCMPayload(data, pushId, timeStamp, expirationTime);
+
+    expect(payload.priority).toEqual('high');
+    expect(payload.timeToLive).toEqual(Math.floor((expirationTime - timeStamp) / 1000));
+    var dataFromPayload = payload.data;
+    expect(dataFromPayload.time).toEqual(timeStamp);
+    expect(dataFromPayload['push_id']).toEqual(pushId);
+    var dataFromUser = JSON.parse(dataFromPayload.data);
+    expect(dataFromUser).toEqual(data);
+    done();
+  });
+
+  it('can generate GCM Payload with too early expiration time', (done) => {
+    //Mock request data
+    var data = {
+      'alert': 'alert'
+    };
+    var pushId = 1;
+    var timeStamp = 1454538822113;
+    var expirationTime = 1454538822112;
+
+    var payload = GCM.generateGCMPayload(data, pushId, timeStamp, expirationTime);
+
+    expect(payload.priority).toEqual('high');
+    expect(payload.timeToLive).toEqual(0);
+    var dataFromPayload = payload.data;
+    expect(dataFromPayload.time).toEqual(timeStamp);
+    expect(dataFromPayload['push_id']).toEqual(pushId);
+    var dataFromUser = JSON.parse(dataFromPayload.data);
+    expect(dataFromUser).toEqual(data);
+    done();
+  });
+
+  it('can generate GCM Payload with too late expiration time', (done) => {
+    //Mock request data
+    var data = {
+      'alert': 'alert'
+    };
+    var pushId = 1;
+    var timeStamp = 1454538822113;
+    var expirationTime = 2454538822113;
+
+    var payload = GCM.generateGCMPayload(data, pushId, timeStamp, expirationTime);
+
+    expect(payload.priority).toEqual('high');
+    // Four week in second
+    expect(payload.timeToLive).toEqual(4 * 7 * 24 * 60 * 60);
+    var dataFromPayload = payload.data;
+    expect(dataFromPayload.time).toEqual(timeStamp);
+    expect(dataFromPayload['push_id']).toEqual(pushId);
+    var dataFromUser = JSON.parse(dataFromPayload.data);
+    expect(dataFromUser).toEqual(data);
+    done();
+  });
+
+  it('can send GCM request', (done) => {
+    var gcm = new GCM('apiKey');
+    // Mock gcm sender
+    var sender = {
+      send: jasmine.createSpy('send')
+    };
+    gcm.sender = sender;
+    // Mock data
+    var expirationTime = 2454538822113;
+    var data = {
+      'expiration_time': expirationTime,
+      'data': {
+        'alert': 'alert'
+      }
+    }
+    // Mock registrationTokens
+    var registrationTokens = ['token'];
+
+    var promise = gcm.send(data, registrationTokens);
+    expect(sender.send).toHaveBeenCalled();
+    var args = sender.send.calls.first().args;
+    // It is too hard to verify message of gcm library, we just verify tokens and retry times
+    expect(args[1].registrationTokens).toEqual(registrationTokens);
+    expect(args[2]).toEqual(5);
+    done();
+  });
+
+  it('can throw on sending when we have too many registration tokens', (done) => {
+    var gcm = new GCM('apiKey');
+    // Mock gcm sender
+    var sender = {
+      send: jasmine.createSpy('send')
+    };
+    gcm.sender = sender;
+    // Mock registrationTokens
+    var registrationTokens = [];
+    for (var i = 0; i <= 2000; i++) {
+      registrationTokens.push(i.toString());
+    }
+
+    expect(function() {
+      gcm.send({}, registrationTokens);
+    }).toThrow();
+    done();
+  });
+});