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# dotenv-flow.rs

A fork of [dotenv-rs](https://github.com/dotenv-rs/dotenv) that adds support for the popular dotenv-flow
loading strategy.


The dotenv-flow strategy works as follows:

- if a DOTENV_ENV environment variable is set, load .env.{DOTENV_ENV}.local (e.g. .env.staging.local)
- load .env.local
- if a DOTENV_ENV environment variable is set, load .env.{DOTENV_ENV} (e.g. .env.staging)
- load .env

Each step will only load variables that are not already present in the environment, so for example variables
in the .env.{DOTENV_ENV}.local file will have the highest priority, followed .env.local and so on.

### Breaking in 0.16.0

- env.{DOTENV_ENV}.local is now loaded before .env.local

## HowTo

### Installation

```sh
cargo add dotenv-flow
```

### Usage

To use this package, add the following line to your main function to load the environment variables from available `.env.*` files:

```rs
fn main() {
  dotenv_flow::dotenv_flow().ok();
}
```


## Tests

To test this project, make sure you pass `--test-threads=1` to `cargo test`, e.g.

```sh
cargo test -- --test-threads=1
```

This is necessary because `cargo test` runs tests in multiple threads by default, but environment variables are process-globals, therefore we need to limit concurrency to avoid race conditions.