react-use/tests/createGlobalState.test.ts

import { act, renderHook } from "@testing-library/react-hooks";
import createGlobalState from "../src/createGlobalState";

describe("useGlobalState", () => {
  it("should be defined", () => {
    expect(createGlobalState).toBeDefined();
  });

  it("both components should be updated", () => {
    const useGlobalValue = createGlobalState(0);
    const { result: result1 } = renderHook(() => useGlobalValue());
    const { result: result2 } = renderHook(() => useGlobalValue());
    expect(result1.current[0] === 0);
    expect(result2.current[0] === 0);
    act(() => {
      result1.current[1](1);
    });
    expect(result1.current[0] === 1);
    expect(result2.current[0] === 1);
  });
});