@applicaster/zapp-react-native-ui-components/Components/Viewport/ViewportEvents/__tests__/viewportEvents.test.js

Applicaster Zapp React Native ui components for the Quick Brick App

import * as React from "react";
import { renderHook } from "@testing-library/react-hooks";
import {
  ViewportEvents,
  useViewportEventsContext,
  ViewportEventContext,
} from "../index";

const event = {
  foo: "bar",
};

const viewportEventsManager = new ViewportEvents(true);

describe("ViewportEvents", () => {
  describe("viewportEventsManager", () => {
    const listener = jest.fn();

    beforeEach(() => {
      listener.mockClear();
      viewportEventsManager.removeListener(listener);
    });

    it("is initialized properly", () => {
      expect(viewportEventsManager).toHaveProperty("listeners", []);
      expect(viewportEventsManager).toHaveProperty("lastEvent", null);
      expect(viewportEventsManager).toHaveProperty("firesLastEventOnAdd", true);
    });

    it("allows to add event listeners", () => {
      viewportEventsManager.addListener(listener);
      expect(viewportEventsManager).toHaveProperty("listeners", [listener]);
    });

    it("allows to remove event listeners", () => {
      viewportEventsManager.addListener(listener);
      viewportEventsManager.removeListener(listener);
      expect(viewportEventsManager).toHaveProperty("listeners", []);
    });

    it("calls the listeners when notifying with an event", () => {
      viewportEventsManager.addListener(listener);
      viewportEventsManager.notify(event);
      expect(listener).toHaveBeenCalledWith(event);
    });

    it("it calls the listener with the last recorded event when adding a new lister", () => {
      const listener2 = jest.fn();
      const lastEvent = { lastEvent: true };
      viewportEventsManager.notify(lastEvent);
      viewportEventsManager.addListener(listener2);
      expect(listener2).toHaveBeenCalledWith(lastEvent);
    });
  });
});

describe("useViewportEventsContext", () => {
  it("returns the context", () => {
    // eslint-disable-next-line react/prop-types
    const wrapper = ({ children }) => (
      <ViewportEventContext.Provider value={viewportEventsManager}>
        {children}
      </ViewportEventContext.Provider>
    );

    const { result } = renderHook(() => useViewportEventsContext(), {
      wrapper,
    });

    expect(result).toHaveProperty("current", viewportEventsManager);
  });
});