Thanks! This is indeed something we overlooked. The basic renderer was still a proof of concept which is why we didn't include it in the 2.4 release notes. Glad that this is noticed before we make it public :)

However, if we were to make it truly env-agnostic, the basic renderer should not be even able to access process, which is a Node-specific global (maybe it also exists in Nashorn, but not in every environment). The process.env.BASIC_RENDERER needs to be converted into constants during the compilation phase. I'll take a look at this as part of 2.5 features, but feel free to try addressing that.

There isn't process in nashorn. I'm all for env-agnostic basic renderer.

I'll try switch from process.env.... to constants

FYI env vars to constant replacement can be configured here

@yyx990803
Something like this?
Another question. How to fix flow

src/server/render-context.js:64
 64:     if (__BASIC_RENDERER__ === true) {
             ^^^^^^^^^^^^^^^^^^ identifier `__BASIC_RENDERER__`. Could not resolve name

looking for __WEEX__ I can't find anything about in config files

Thanks for looking into this! Instead of making the whole rendering synchronous, we can just use a platform specific deferring function instead. In c5d0fa0 I've made it preferring process.nextTick -> Promise.then -> setTimeout.

In php-v8js Promise is already supported; in Nashorn, you can polyfill setTimeout using Java timers.

Just for curiosity. Is there anything wrong with synchronous approach?
In my free time I'm working on Vue SSR in pure java (core still use Nashorn) and if there are some issues with synchronous approach it is better to me know this early :)

Vue's SSR is designed to be async first, because there are many operations that may be async during render:

• async components
• external cache calls
• unwinding deep call stacks

Making things sync is just fundamentally against the design.