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alt="envar rainbow logo">

A collection of functions for checking/getting/setting **environment variables** in **`Elixir`**.

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## Why?

We needed a way of checking that environment variables were defined 
and improving the developer experience when they are not.
## What?

**`envar`** is our solution to a very specific problem:
the developer experience when a required environment variable is undefined. 


<br />


## How?

### Installation

Install the package
by adding `envar` to your list of dependencies in your `mix.exs` file:

```elixir
def deps do
  [
    {:envar, "~> 1.0.3"}
  ]
end
```

## Usage

Load an `.env` file 
containing a line-separated list of environment variables 
on your `localhost`:

```elixir
Envar.load(".env")
```

That will locate the `.env` file in your project 
and set each environment variable in it.

<br />


When you need to retrieve a specific environment variable,
use the following:

```elixir
DATABASE_URL = Envar.get("DATABASE_URL")
```

<br />

If you need to check that a variable is set, 
use `is_set?/1`

```elixir
if Envar.is_set?("Heroku") do
  # do stuff on Heroku
end
```

To check if _any_ of the variables in a `List` are set,
invoke `Envar.is_set_any?/1`:

```elixir
if Envar.is_set_any?(["HEROKU", "FLYIO"]) do
  # Do something on non-prod environment
end
```


For more detail, please see docs: 
https://hexdocs.pm/envar/Envar.html#functions

<br />

## Context

We created this module after doing
a search of the `Elixir` (Hex.pm)
ecosystem, <br />
see:
[dwyl/learn-environment-variables/issues/18](https://github.com/dwyl/learn-environment-variables/issues/18)

There are several modules available,
we wanted something very basic/specific to our needs. <br />
We don't expect anyone else to use this;
it's Open Source 
because that's just what we do: <br />
[/manifesto.md#open-source-always](https://github.com/dwyl/start-here/blob/master/manifesto.md#open-source-always)