Example is a modified test from Morgan Roderick's PubSubJS. "test should call subscriber": function () { var spy = sinon.spy(); PubSub.subscribe("message", spy); PubSub.publishSync("message", undefined); assertTrue(spy.called); } Example is a modified test from Morgan Roderick's PubSubJS. "test should call all subscribers when exceptions": function () { var spy = sinon.spy(); var stub = sinon.stub