Example of using chromedp to prerender a create-react-app frontend using fake SSR via chrome headless

ssr_test.go

package main

import (
	"context"
	"io/ioutil"
	"log"
	"strings"
	"testing"

	"github.com/chromedp/cdproto/dom"
	"github.com/chromedp/chromedp"
)

func TestSSRofCRA(t *testing.T) {

	// create context, this would come from client if using HTTP
	ctx, cancel := chromedp.NewContext(context.Background())
	defer cancel()

	// create-react-app uses port 3000 by default
	var res string
	err := chromedp.Run(ctx, scrapIt("http://localhost:3000/", &res))
	if err != nil {
		t.Fatal(err)
	}

	ioutil.WriteFile("rendered.html", []byte(res), 0664)

	log.Println(strings.TrimSpace(res))
}

func scrapIt(url string, str *string) chromedp.Tasks {
	return chromedp.Tasks{
		chromedp.Navigate(url),
		chromedp.ActionFunc(func(ctx context.Context) error {
			node, err := dom.GetDocument().Do(ctx)
			if err != nil {
				return err
			}
			*str, err = dom.GetOuterHTML().WithNodeID(node.NodeID).Do(ctx)
			return err
		}),
	}
}

// Alternative, less-stable fetch using chrome directly
// out, err := exec.Command("sh", "-c", "/root/tools/chromium-latest-linux/latest/chrome --headless --no-sandbox --dump-dom "+url).Output()
// if err != nil {
// 	log.Fatal(err)
// }
// fmt.Printf("%s\n", out)

• https://www.reddit.com/r/golang/comments/bvnzd3/how_do_you_guys_handle_javascript_frontends/

• https://www.reddit.com/r/reactjs/comments/bvnkp8/react_framework_for_both_web_and_mobile_with/

• Google Search and JavaScript Sites (Google I/O'19): https://www.youtube.com/watch?v=Ey0N1Ry0BPM

• https://hackernoon.com/whats-new-with-server-side-rendering-in-react-16-9b0d78585d67