Add bulk subscribe support.

static/cosmopolite.js

@@ -254,15 +254,28 @@ Cosmopolite.prototype.shutdown = function() {
  *
  * Start receiving messages sent to this subject via the onMessage callback.
  *
- * @param {Cosmopolite.typeSubjectLoose} subject
+ * @param {Cosmopolite.typeSubjectLoose|Array.<Cosmopolite.typeSubjectLoose>}
+ *     subjects
  * @param {?number=} opt_messages Number of recent messages to request;
  *     0 for none, -1 for all
  * @param {?number=} opt_lastID ID of last message received; fetch messages
  *     since
- * @return {Promise}
+ * @return {Promise|Array.<Promise>}
  */
-Cosmopolite.prototype.subscribe = function(subject, opt_messages, opt_lastID) {
+Cosmopolite.prototype.subscribe = function(subjects, opt_messages, opt_lastID) {
-  return this.newPromise_(function(resolve, reject) {
+  var single = false;
+
+  if (!(subjects instanceof Array)) {
+    single = true;
+    subjects = [subjects];
+  }
+
+  var ret = [];
+  var rpcs = [];
+  for (var i = 0; i < subjects.length; i++) {
+    var subject = subjects[i];
+
+    ret.push(this.newPromise_(function(resolve, reject) {
       /** @type {Cosmopolite.typeSubject} */
       var canonicalSubject = this.canonicalSubject_(subject);
       /** @type {string} */
@@ -286,7 +299,7 @@ Cosmopolite.prototype.subscribe = function(subject, opt_messages, opt_lastID) {
         args['last_id'] = opt_lastID;
       }
 
-    this.sendRPC_('subscribe', args, function(response) {
+      var onSuccess = function(response) {
         /** @type {string} */
         var result = response['result'];
         if (result == 'ok') {
@@ -303,8 +316,22 @@ Cosmopolite.prototype.subscribe = function(subject, opt_messages, opt_lastID) {
           delete this.subscriptions_[subjectString];
           reject(new Error(result));
         }
+      };
+      rpcs.push({
+        'command': 'subscribe',
+        'arguments': args,
+        'onSuccess': onSuccess
       });
-  }.bind(this));
+    }.bind(this)));
+  }
+
+  this.sendRPCs_(rpcs);
+
+  if (single) {
+    return ret[0];
+  } else {
+    return ret;
+  }
 };
 
 

static/test.js

@@ -138,6 +138,30 @@ asyncTest('Message round trip without channel', function() {
   cosmo.subscribe(subject, -1);
 });
 
+asyncTest('Bulk subscribe', function() {
+  expect(2);
+
+  var subject1 = randstring();
+  var subject2 = randstring();
+  var message = randstring();
+
+  var messages = 0;
+
+  var callbacks = {
+    'onMessage': function(e) {
+      equal(e['message'], message, 'message matches');
+      if (++messages == 2) {
+        cosmo.shutdown();
+        start();
+      }
+    }
+  };
+
+  var cosmo = new Cosmopolite(callbacks, null, randstring());
+  cosmo.sendMessage(subject1, message);
+  cosmo.sendMessage(subject2, message);
+  cosmo.subscribe([subject1, subject2], -1);
+});
 
 asyncTest('Complex object', function() {
   expect(2);