import PubSub from "../../js/lib/pub_sub"; describe("PubSub", () => { test("subscribed callback is called on the specified topic", () => { const pubsub = new PubSub(); const callback1 = jest.fn(); const callback2 = jest.fn(); pubsub.subscribe("topic1", callback1); pubsub.subscribe("topic2", callback2); pubsub.broadcast("topic1", { data: 1 }); expect(callback1).toHaveBeenCalledWith({ data: 1 }); expect(callback2).not.toHaveBeenCalled(); }); test("unsubscribed callback is not called on the specified topic", () => { const pubsub = new PubSub(); const callback1 = jest.fn(); pubsub.subscribe("topic1", callback1); pubsub.unsubscribe("topic1", callback1); pubsub.broadcast("topic1", {}); expect(callback1).not.toHaveBeenCalled(); }); });