State of the project

[stereobooster]

The goal is to expand the tooling with all the bells and whistles that penthouse and critical etc. has. Including NPM packaging, split between lib and cli, unit tests, documentation, maturity.

There is react-snap which is basically doing what you describe. Do not pay attention to the name, it does not depend on React or create-react-app, but it uses create-react-app conventions. It can work with any Single Page Application to pre-render it to HTML. Plus it uses minimalcss to extract critical CSS and injects it directly in the page source and uses LoadCSS to load original CSS later. I feel like our projects can share some functionality and configurations.

There are also prep and react-snapshot, which can prerender, but does not do critical CSS magic.

[stereobooster]

// Note! This opens one URL at a time synchronous
  for (let i = 0; i < urls.length; i++) {
    const url = urls[i]
    // console.log(url, i);
    const page = await browser.newPage()

react-snap uses highland to process urls concurrently.

 queue
    .map(x => _(fetchPage(x)))
    .parallel(options.concurrency)