server.js

const fs = require('fs')
const path = require('path')
const LRU = require('lru-cache')
const express = require('express')
const favicon = require('serve-favicon')
const compression = require('compression')
const microcache = require('route-cache')
const resolve = (file) => path.resolve(__dirname, file)
const { createBundleRenderer } = require('vue-server-renderer')

const isProd = process.env.NODE_ENV === 'production'
const useMicroCache = process.env.MICRO_CACHE !== 'false'
const serverInfo =
	`express/${require('express/package.json').version}` +
	`vue-server-renderer/${require('vue-server-renderer/package.json').version}`

const app = express()

function createRenderer(bundle, options) {
	return createBundleRenderer(
		bundle,
		Object.assign(options, {
			cache: LRU({
				max: 1000,
				maxAge: 1000 * 60 * 15,
			}),
			basedir: resolve('./dist'),
			runInNewContext: false,
		})
	)
}

let renderer
let readyPromise
const templatePath = resolve('./src/index.template.html')

if (isProd) {
	const template = fs.readFileSync(templatePath, 'utf-8')
	const bundle = require('./dist/vue-ssr-server-bundle.json')

	const clientManifest = require('./dist/vue-ssr-client-manifest.json')

	renderer = createRenderer(bundle, {
		template,
		clientManifest,
	})
} else {
	readyPromise = require('./build/setup-dev-server')(
		app,
		templatePath,
		(bundle, options) => {
			renderer = createRenderer(bundle, options)
		}
	)
}

const serve=(path,cache)=>express.static(resolve(path),{
    maxAge:cache&&isProd ? 1000*60*60*24*30:0
})

app.use(compression({threshold:0}))
app.use(favicon('./public/logo-48.png'))
app.use('/dist',serve('./dist',true))
app.use('/public',serve('./public',true))
app.use('/manifest.json',serve('./manifest.json',true))
app.use('/service-worker.js',serve('./dist/service-worker.js'))

app.use(microcache.cacheSeconds(1,req=>useMicroCache && req.originalUrl))

function render(req,res){
    const s=Date.now()

    res.setHeader('Content-Type','text/html')
    res.setHeader('Server',serverInfo)

    const handleError=err=>{
        if(err.url){
            res.redirect(err.url)
        }else if(err.code===404){
            res.status(404).send('404|Page Not Found')
        }else{
            res.status(500).send('500|Internal Server Error')
            console.error(`error during render :${req.url}`)
            console.log(err.stack)
        }
    }

    const context={
        title:'Vue HN 2.0',
        url:req.url
    }
    renderer.renderToString(context,(err,html)=>{
        if(err){
            return handleError(err)
        }
        res.send(html)
        if(!isProd){
            console.log(`whole request: ${Date.now()-s} ms`)
        }

    })
}

app.get('*',isProd ? render:(req,res)=>{
    readyPromise.then(()=>render(req,res))
})

const port=process.env.PORT || 8080
app.listen(port,()=>{
    console.log(`server started at localhost:${port}`)
})