如何模拟useEffect内部的fetch函数？

import React, { useState, useEffect } from 'react';

function MyComponent() {
  const [data, setData] = useState(null);

  useEffect(() => {
    const fetchData = async () => {
      try {
        const response = await fetch('API_URL');
        const result = await response.json();
        setData(result);
      } catch (error) {
        console.error(error);
      }
    };

    fetchData();
  }, []);

  return (
    <div>
      {/* 渲染数据 */}
    </div>
  );
}

npm install -g json-server

{
  "posts": [
    { "id": 1, "title": "Post 1" },
    { "id": 2, "title": "Post 2" },
    { "id": 3, "title": "Post 3" }
  ]
}

json-server --watch db.json --port 3001

import React, { useState, useEffect } from 'react';
import axios from 'axios';

function MyComponent() {
  const [data, setData] = useState([]);

  useEffect(() => {
    const fetchData = async () => {
      try {
        const response = await axios.get('http://localhost:3001/posts');
        setData(response.data);
      } catch (error) {
        console.error(error);
      }
    };

    fetchData();
  }, []);

  return (
    <div>
      {/* 渲染数据 */}
    </div>
  );
}