This is only in the same experimental exports as `resume`. Useful with
Postpone/Halt.
We already have `prerender()` to create a partial tree with postponed
state. We also have `resume()` to dynamically resume such a tree.
This lets you do a new prerender by resuming an already existing
postponed state. Basically creating a chain of preludes. The next
prelude would include the scripts to patch up the document.
This mostly just works since both prerender and resume are already
implemented using the same code so we just enable both at the root. I'm
sure we'll find some edge cases since this wasn't considered when it was
first written but so far I've only found an unrelated existing bug with
`keyPath` fixed here.
This disables symbol renaming in production builds. The original
variable and function names are preserved. All other forms of
compression applied by Closure (dead code elimination, inlining, etc)
are unchanged — the final program is identical to what we were producing
before, just in a more readable form.
The motivation is to make it easier to debug React issues that only
occur in production — the same reason we decided to start shipping
sourcemaps in #28827 and #28827.
However, because most apps run their own minification step on their npm
dependencies, it's not necessary for us to minify the symbols before
publishing — it'll be handled the app, if desired.
This is the same strategy Meta has used to ship React for years. The
React build itself has unminified symbols, but they get minified as part
of Meta's regular build pipeline.
Even if an app does not minify their npm dependencies, gzip covers most
of the cost of symbol renaming anyway.
This saves us from having to ship sourcemaps, which means even apps that
don't have sourcemaps configured will be able to debug the React build
as easily as they would any other npm dependency.
This joins the static (prerender) builds with the server builds but
doesn't change the public entry points.
The idea of two separate bundles is that we'd have a specialized build
for Fizz just for the prerender that could do a lot more. However, in
practice the code is implemented with a dynamic check so it's in both.
It's also not a lot of code.
At the same time if you do have a set up that includes both the
prerender and the render in the same build output, this just doubles the
server bundle size for no reason.
So we might as well merge them into one build. However, I don't expose
the `prerender` from `/server`. Instead it's just exposed from the
public `/static` entry point. This leaves us with the option to go back
to separate builds later if it diverges more in the future.
