potenv

A Rust implementation of the POSIX-compliant dotenv file format specification.

Usage

Load environment variables from a .env file in the current working directory:

potenv::load([".env"]).expect("Failed to load .env file.");

For convenience, an iterator over the loaded variables is returned:

let vars = potenv::load([".env"]).unwrap();for(name, value)in vars {assert_eq!(value, std::env::var(name).unwrap());}

If you just want to evaluate the dotenv files without loading them into the environment, use the following:

use potenv::Potenv;let vars = Potenv::default().evaluate([".env"]).unwrap();

By default, environment variables take precedence over variables defined in a dotenv file.

When this is not the desired behaviour, you can use the following:

use potenv::Potenv;let vars = Potenv::default().override_env(true).load([".env"]).unwrap();

If you don't want to read from and/or write to the process environment, you can implement the [env::EnvProvider] trait.

For example, this is how to frobnicate all variables:

use potenv::{Potenv, env::EnvProvider};pubstructFrobnicator;implEnvProviderforFrobnicator{fnvar(&self,name:&str) -> Option<String>{Some("frobnicated".into())}fnset_var(&mutself,name:&str,value:&str){}}let vars = Potenv::new(Frobnicator,false).evaluate([".env"]).unwrap();for(name, value)in vars {assert_eq!("frobnicated", value);}

If you just want to mock the environment in unit-tests, the [env::EnvProvider] trait is implemented for HashMap<String, String>:

use std::collections::HashMap;use potenv::Potenv;letmut mock = HashMap::new();
mock.insert("name".into(),"value".into());let vars = Potenv::new(mock,false).evaluate([".env"]).unwrap();