Add tests to verify Model.exists() is working

test/remote-models.test.js

@@ -200,6 +200,29 @@ describe('Remote model tests', function() {
       });
   });
 
+  describe('Model.exists(id, callback)', function() {
+    it('should return true when the model with the given id exists',
+      function(done) {
+        ServerModel.create({first: 'max'}, function(err, user) {
+          if (err) return done(err);
+          ClientModel.exists(user.id, function(err, exist) {
+            if (err) return done(err);
+            assert.equal(exist, true);
+            done();
+          });
+        });
+      });
+
+    it('should return false when there is no model with the given id',
+      function(done) {
+        ClientModel.exists('user-id-does-not-exist', function(err, exist) {
+          if (err) return done(err);
+          assert.equal(exist, false);
+          done();
+        });
+      });
+  });
+
   describe('Model.findById(id, callback)', function() {
     it('should return null when an instance does not exist',
       function(done) {