Generate files only when necessary

[eric-burel]

Hi, Some frameworks like Next.js are expected to have weird conventions. In Next (v12.3 at the time of writing), ".env", ".env.development", ".env.production" and ".env.test" are tracked files, and ".env.local" are untracked* files.

Currently, "modenv" will generate ".env.production" and ".env.example" if they do not exists, but these files do not make sense in Next.js (and maybe other frameworks).

So what I propose:

• if the project has a .gitignore that matches at least one ".env" rule, we consider tracking to be set, do not touch it => already done
• if the project has a ".env" file, we consider files to be set, do not generate anything => this is more framework agnostic, as we suppose that if there is already a .env, it means that .env files already has been set.

Specific scenario: In Next.js for instance, ".env"/".env.local" are equivalent to ".env.example"/".env" in other projects. In Remix, the initalization is handled by a custom script specific to each stack, so we don't need modenv eitther. Normal scenario: It will still work for other projects where there is no ".env" set as a default or just a ".env.example" the normal workflow happens, generating ".env", ".env.example" and ".env.production"

A small thing that bugged me: the code is different for generating ".env" or ".env.production" based on ".env.example", why? It seems the logic is the same but you use 2 different way, the ".env.production" code is terser.

Another Rust related thing: do you use &str or &'static str for global string values?

[kurtbuilds]

This sounds pretty reasonable to me.

It's a &'static str, but it's fine to elide the 'static.

The idea for the differing behavior between populating .env versus .env.production is that in my usage, I'll sometimes keep .env.example populated with default values, e.g. PORT=5000 HOST=0.0.0.0, but I don't necessarily want those to populate by default into .env.production.

[kurtbuilds]

Once this runs, I'm happy to merge in and cut a release.

[kurtbuilds]

Published as 0.9.0!