Why did vite select import.meta.env for providing environment variables?

[woohm402]

Hi!

First, thank you for maintaining such a fancy tool. I'm happy using vite and my developing experience got much better with vite.

This discussion is not about troubleshooting or feature request. I am just curious about:

Why did vite select import.meta.env for providing environment variables?

After some researches, I thought these could be the reason:

• import.meta is included in ECMA2021 spec, while process.env is not. import.meta is more "official" one.
• import.meta can be used in browser-side while process object cannot. So there are some technical issues, because vite uses browser-supported native ESModule.
• Because process.env is legacy (?)

However, there are some downsides also:

• process.env is heavily used in frontend ecosystem. Many third-party libraries & existing projects would be break if vite does not support process.env. Of course, we can use process.env in vite using plugins like vite-plugin-environment. Anyway there is a big difference between "supported officially" and "supported by third-party plugin".
• import.meta is an official one, but import.meta.env is not an official one. As I know, vite is the only one that uses import.meta for providing env variables. So it didn't have to be import.meta, many other solutions would have existed. (ex. globalThis?) If some other thing becomes an "official & trending" thing for env in future, vite ecosystem developers will have to migrate their codebase.
• Vite already supports runtime code replacement for process.env.NODE_ENV (source code here). So with similar thing, it would not be technically hard to support both process.env and import.meta.env, or only process.env.

So returning to my first question: why did vite select import.meta.env for environment over process.env? What was your basis of judgement? Why it had to be import.meta.env over other existing solutions?

Thank you for reading my long question! 😄

[Enormus]

Great question! And it still hasn't been answered after two years? Fascinating (in the Spock way).