使用useEffect()钩子测试Jest中的函数

import { render, act } from '@testing-library/react';
import { useEffect } from 'react';

// 模拟要测试的函数
const fetchData = async () => {
  // 执行异步操作
};

// 在测试中使用useEffect()钩子
const TestComponent = () => {
  useEffect(() => {
    fetchData();
  }, []);

  return <div>Test Component</div>;
};

// 使用Jest进行测试
describe('TestComponent', () => {
  it('should call fetchData on mount', async () => {
    const fetchDataSpy = jest.spyOn(global, 'fetchData');
    fetchDataSpy.mockImplementation(() => Promise.resolve());

    await act(async () => {
      render(<TestComponent />);
    });

    expect(fetchDataSpy).toHaveBeenCalled();

    fetchDataSpy.mockRestore();
  });
});