Xpresser/Env

##### This package can be used in any NodeJs related project.

- Loads your env file.
- Interpolates environment variables.
- Cast strings to boolean.
- Checks for required env variables.
- Validate env variables.

Installation

``shell
npm i @xpresser/env

OR

yarn add @xpresser/env
`

Functions

Two functions are exported by the package.

- LoadEnv - Loads your env file with option for required keys (without validation).
- Env - Loads and validates your environment variables with a simple schema. (Typescript Friendly)

Example File

Using this example local.env file

`dotenv
APP_DOMAIN=localhost
APP_FOLDER="/blog"
APP_PORT=3000
APP_URL="${AppDomain}:${AppPort}${AppFolder}"

CONNECT_TO_API=true
#API_KEY="somekey"
`

$3


The LoadEnv function accepts the path to the env file as first argument and options object as the second argument.
The options object can have the following properties:

| Key | Type | Default | Description |
|---------------|-----------|---------|------------------------------------------------------------------------------------------------------------------------------------------------|
| castBoolean | Boolean | true | if enabled, all string "true" or "false" will be converted to booleans. |
| required | Array | [] | The env loader will check if all the keys defined in this array exists in your specified env file else it stops the process and logs an error. |
| endProcess | Boolean | true | By default process.exit() is called when required keys are missing. to throw Error instead, set this to false. |


`javascript
const {LoadEnv} = require('@xpresser/env');
const env = LoadEnv('path/to/local.env', {
castBoolean: true,
required: ['API_KEY']
});

console.log(env);
`
##### Result:
`sh
The following ENV variables are REQUIRED but not found.
[ 'API_KEY' ]
`
If you uncomment the API_KEY line in your env file, your result will be
`
{
APP_DOMAIN: 'localhost',
APP_FOLDER: '/blog',
APP_PORT: '3000',
APP_URL: 'localhost:3000/blog',
CONNECT_TO_API: true,
API_KEY: 'somekey'
}
`

$3


The Env function accepts the
- path to the env file as first argument,
- schema object as the second argument
- options object as the third argument.

The options object can have the following properties:

| Key | Type | Default | Description |
|---------------|-----------|---------|------------------------------------------------------------------------------------------------------------------------------------------------|
| required | Array | [] | The env loader will check if all the keys defined in this array exists in your specified env file else it stops the process and logs an error. |
| endProcess | Boolean | true | By default process.exit() is called when required keys are missing. to throw Error instead, set this to false. |


Note: The options object does not include the castBoolean property like the LoadEnv function.
This is because the Env schema requires and sets castBoolean to be true


`javascript
const {Env} = require('@xpresser/env');

const env = Env('path/to/local.env', {
APP_DOMAIN: Env.is.string('Localhost'), // can have defaults
APP_FOLDER: Env.is.string(),
APP_PORT: Env.is.number(3000),
APP_URL: Env.is.string(),
CONNECT_TO_API: Env.is.boolean(),
// optional envs
API_KEY: Env.optional.string()
});

// env will be typed and validated.
`

$3


The required array also accepts functions to evaluate conditions.
For example, we want to require API_KEY only when: CONNECT_TO_API===true

`javascript
const {LoadEnv, Env} = require('@xpresser/env');

const required = [
'CONNECT_TO_API',
(envs) => {
if (envs['CONNECT_TO_API'] === true) {
return 'API_KEY';
}
}
]

const env = envLoader('path/to/local.env', {required});
// OR
const env = Env('path/to/local.env', {
// declare env variables schema
}, {required})

console.log(env);
`
This will check if API_KEY exists only if CONNECT_TO_API is true.
You can add as many functions as you want. The loader will run all of them and add returned values to the required` array.

Note: The function can also return an array of strings. the loader will concatenate the strings with the required array.