server-render.js
const ejs = require("ejs")
module.exports = async(ctx, renderer, template) => {
  ctx.headers["Content-Type"] = "text/html"
  const context = { url: ctx.path }
  console.log(ctx.path)
  console.log("renderer", renderer);
  try {
    const appString = await renderer.renderToString(context)
    console.log("appString", appString);
    const {
      title
    } = context.meta.inject()
    const html = ejs.render(template, {
      appString,
      title: title.text(),
      style: context.renderStyles(),
      scripts: context.renderScripts()
    })
    ctx.body = html
  } catch (err) {
    console.log("appString", "errr");
    console.log("render error", err)
    throw err
  }
}
ssr.js
const Router=require("koa-router")
const path=require("path")
const fs=require("fs")
const VueServerRender=require("vue-server-renderer")
const serverRender=require("./server-render")
const clientManifest=require("../../public/vue-ssr-client-manifest.json")
const renderer= VueServerRender.createBundleRenderer(
  path.join(__dirname,"../../server-build/vue-ssr-server-bundle.json"),
  {
    inject:false,
    clientManifest
  }
)
console.log("renderer",renderer)
const template=fs.readFileSync(
  path.join(__dirname,"../server.template.ejs"),
  "utf-8"
)
const pageRouter=new Router()
pageRouter.get("*",async (ctx)=>{
  await serverRender(ctx,renderer,template)
})
module.exports=pageRouter
error message
 
 
 A  renderer.renderToString (context)  error was reported by printing 
put the code in githunb
https://github.com/fridaydream/vue-ssr-example.git
 after executing the commands  npm run build  and  npm start , I reported an error 
