vite-handle.js

const fs = require('fs')
const path = require('path')
const isTest = process.env.NODE_ENV === 'test' || !!process.env.VITE_TEST_BUILD

function queryStringToObject (query) {
    const result = query.match(/\?(.*)/)
    if (!result) return {}
    return Object.fromEntries(new URLSearchParams(result[1]))
}

async function createViteHandle ({ root = process.cwd(), dev = true, index, dist }) {
    let vite = null
    let staticServe = null
    const indexHTML = fs.readFileSync(index, 'utf-8')

    if (dev) {
        vite = await require('vite').createServer({
            root,
            logLevel: isTest ? 'error' : 'info',
            server: {
                middlewareMode: true
            }
        })
    } else {
        staticServe = require('serve-static')(path.resolve(dist, 'client'), {
            index: false
        })
    }

    return async (req, res) => {
        if (dev) {
            vite.middlewares(req, res, () => {
                handleRender(req, res, {
                    template: indexHTML,
                    dev,
                    vite
                })
            })
        } else {
            staticServe(req, res, () => {
                handleRender(req, res, {
                    template: indexHTML,
                    dev,
                    vite,
                    dist
                })
            })
        }
    }
}

async function handleRender (req, res, { template, dev, vite, dist }) {
    try {
        const url = req.url

        let render
        if (dev) {
            // always read fresh template in dev
            template = await vite.transformIndexHtml(url, template)
            render = (await vite.ssrLoadModule('/src/entry-server.jsx')).render
        } else {
            render = require(path.resolve(dist, 'server/entry-server.js')).render
        }

        const context = {
            isSSR: true,
            query: req.query || queryStringToObject(req.url),
            url: req.originalUrl,
            req
        }

        const { appHtml, propsData, redirect } = await render(url, context)

        if (redirect) {
            res.statusCode = 302
            res.setHeader('Location', redirect)
            res.end(`Location:${redirect}`)
            return
        }

        const ssrDataText = JSON.stringify(propsData)
            .replace(/\//g, '\\/')

        const html = template
            .replace('<!--init-props-->', `<script id="ssr-data" type="text/json">${ssrDataText}</script>`)
            .replace(`<!--app-html-->`, appHtml)

        res.statusCode = 200
        res.setHeader('Content-Type', 'text/html; utf-8')
        res.end(html)
    } catch (err) {
        dev && vite.ssrFixStacktrace(err)
        console.error(err)
        res.statusCode = 500
        res.end('Server Error')
    }
}

module.exports = createViteHandle