详解React ISR如何实现Demo

import fs from 'fs/promises';
import { renderToString } from 'react-dom/server';
import React from 'react';
import Post from './ui/Post';
import List from './ui/List';
async function build(type: 'list'): Promise<void>;
async function build(type: 'post', name: string): Promise<void>;
async function build(type: 'list' | 'post', name?: string) {
    if (type === 'list') {
        const posts = await fs.readdir('posts');
        await fs.writeFile(
            'dist/index.html',
            `<div id="root">${renderToString(
                <List
                    list={posts.map(post => {
                        delete require.cache['posts/' + post];
                        return { ...require('./posts/' + post), key: post.replace('.json', '') };
                    })}
                />
            )}</div>`
        );
    } else {
        delete require.cache['posts/' + name];
        const postInfo = require('./posts/' + name);
        const fileName = `dist/posts/${name}.html`;
        await fs.writeFile(fileName, `<div id="root">${renderToString(<Post data={postInfo} />)}</div>`);
    }
}
export default build;

import fs from 'fs';
import build from './build-util';
// make sure the dir exists
if (!fs.existsSync('dist')) {
    fs.mkdirSync('dist');
}
if (!fs.existsSync('dist/posts')) {
    fs.mkdirSync('dist/posts');
}
// get all the files in posts
const posts = fs.readdirSync('posts');
(async () => {
    for await (const post of posts) {
        await build('post', post.replace('.json', ''));
    }
    await build('list');
})();

import express from 'express';
import path from 'path';
import fs from 'fs';
import build from '../build-util';
const app = express();
const expiresTime = 1000 * 60 * 10;
app.use(function (req, res, next) {
    setTimeout(() => {
        const filename = req.path.indexOf('.html') >= 0 ? req.path : req.path + 'index.html';
        // get the file's create timestamps
        fs.stat(path.join('./dist', filename), function (err, stats) {
            if (err) {
                console.error(err);
                return;
            }
            if (Date.now() - +stats.mtime > expiresTime) {
                console.log(filename, 'files expired, rebuilding...');
                if (filename === '/index.html') {
                    build('list');
                } else {
                    build('post', path.basename(filename).replace('.html', ''));
                }
            }
        });
    });
    next();
});
app.use(express.static('dist'));
app.listen(4000, () => {
    console.log('Listening on port 4000');
});