[SSR] Development server that includes SSR. (Roadblocked 🛑)

[arpowers]

Is your feature request related to a problem? Please describe.

I am attempting to create a server-side rendered development server using Vite. Most everything is working except for one challenging issue.

When rendering HTML on the server, we need to use files generated by ssrBuild however this build takes around 20 seconds in my case and it prevents "live" development since each change would require a full run of ssrBuild (plus server restart)

Describe the solution you'd like
It should be possible to run ssrBuild with an incremental "watch" that regenerates the needed modules into the server "dist" folder. At least there should be a way to make this pluggable.

Describe alternatives you've considered
I looked at available way to create an ssrBuild that updates based on changes.

Additional context

SSR is a super important feature for enterprise applications and even applications like blogs, forums, etc... NOT for performance reasons, but rendered source and meta handling is very important for syndication and SEO.

In development, we need to validate hydration and insure proper fetching of data needed for rendering; therefore, using client side only in dev is a less than idea option (ultimately unworkable for big-boy apps)

@yyx990803 please give me some feedback, i know you're busy.

[underfin]

Please track here #972