Add support for re-subscribing to the same subject with different message fetching parameters.

static/test.js

@@ -275,7 +275,7 @@ test('getMessages/subscribe', function() {
 });
 
 asyncTest('subscribe barrier', function() {
-  expect(2);
+  expect(3);
 
   var subject = randstring();
   var message = randstring();
@@ -287,6 +287,7 @@ asyncTest('subscribe barrier', function() {
       // We are validating that the message event generated by the subscribe
       // call has already been processed by the time this promise fires
       equal(cosmo.getMessages(subject).length, 1, 'one message');
+      equal(cosmo.getMessages(subject)[0]['subject']['name'], subject, 'subject matches');
       equal(cosmo.getMessages(subject)[0]['message'], message, 'message matches');
       cosmo.shutdown();
       start();
@@ -294,6 +295,28 @@ asyncTest('subscribe barrier', function() {
   });
 });
 
+asyncTest('resubscribe', function() {
+  expect(4);
+
+  var subject = randstring();
+  var message = randstring();
+
+  var cosmo = new Cosmopolite({}, null, randstring());
+
+  cosmo.sendMessage(subject, message).then(function() {
+    cosmo.subscribe(subject).then(function() {
+      equal(cosmo.getMessages(subject).length, 0, 'zero messages');
+      cosmo.subscribe(subject, -1).then(function() {
+        equal(cosmo.getMessages(subject).length, 1, 'one message');
+        equal(cosmo.getMessages(subject)[0]['subject']['name'], subject, 'subject matches');
+        equal(cosmo.getMessages(subject)[0]['message'], message, 'message matches');
+        cosmo.shutdown();
+        start();
+      });
+    });
+  });
+});
+
 
 module('dev_appserver only');