Customizing env variable prefix - SNOWPACK_PUBLIC_

[madhavarshney]

Would it make sense to allow customization of the env variable prefix SNOWPACK_PUBLIC_? I'm looking to use it in cases where there is an existing codebase where I'd like to use snowpack for development but not necessarily change all the existing references to env.XYZ_*.

Additionally, more control over which env variables are included in the build could also be useful. Maybe a function that takes in all env variables and returns the ones that should be included in the build?

Just a proposal. Thanks!

[FredKSchott]

Thanks for the proposal! Definitely interested to hear if others would like this

[mikestopcontinues]

I particularly like the function config. Leave the default (var) => var.startsWith('SNOWPACK_PUBLIC_'), but let the dev override it.