nenv

Table of Contents

• nenv
  • Install
  • Usage
  • API
    • env([value])
    • env.value
    • env.valid
    • env.defined
    • env.get()
    • env.set(val)
    • env.keys
    • env.map
    • env.jsonify()
    • nenv.defaults
    • nenv.cache
    • nenv.get
    • nenv.set
  • Environments
  • Getter
  • Example
  • Developer
    • Test
    • Readme
  • License

nenv

Utility for mananging node development environments.

Requires node and npm.

Install

npm i nenv --save

Usage

var env = require('nenv')();
if(!env.defined) {
  // do something when no environment was specified
  // maybe: env.set(env.DEVEL) or whichever default you want
}else if(!env.valid) {
  // do something when the specified environment is invalid
}else if(env.test) {
  // do something for test environment
}

API

function nenv([environments, get, set])

• environments: Array or object of custom environments, if not specified the defaults are used.
• get: A custom function for getting the environment value (optional).
• set: A custom function for setting the environment value (optional).

env([value])

Determines if an environment value is valid. Returns false if the supplied value is invalid or the string key for the environment if the value is a known environment alias.

If no value is supplied then env.value is used which allows testing whether the default value is valid by calling with no arguments.

env.value

The value returned from get() when nenv() was called, the initial environment value.

env.valid

Boolean that determines whether env.value is a recognised environment.

env.defined

Determines whether an initial value (env.value) was defined.

env.get()

Get the current value of the environment, the default implementation returns process.env.NODE_ENV.

env.set(val)

Set the current value of the environment, the default implementation returns false if the supplied value is not a known environment alias otherwise a function that may be called to revert to the previous value.

env.keys

Array of environment keys.

env.map

Map of environment keys to arrays of string aliases for the environment.

env.jsonify()

Return an object suitable for passing to JSON.stringify.

nenv.defaults

Default values to use.

['test', 'devel', 'stage', 'production'];

nenv.cache

A cache created the first time nenv() was invoked. Typically you would always want to share the same environment query:

var nenv = require('nenv')
  , env = nenv()
  , newenv = nenv()
  // bypass cache and get a new query function using defaults
  , altenv = nenv(true);
console.log(env === newenv);
console.log(env === altenv);

You can bypass the cached instance by passing arguments to nenv() or alternatively you could delete nenv.cache to force a new query to be created.

nenv.get

Default get function.

nenv.set

Default set function.

Environments

Pass an object or array to define your available environments. Passing an object allows specifying multiple keys as aliases for the environment, useful to alias shortcuts for longer environment identifiers.

var nenv = require('nenv');
console.dir(nenv(['test', 'dev', 'stage']));
console.dir(nenv({production: ['production', 'pro'], dev: 'dev', test: 'test'}));

Getter

Use a fallback value by supplying a get function:

var nenv = require('nenv');
function fallback() {
  return process.env.NODE_ENV || this.PRODUCTION;
}
var env = nenv(fallback);
console.dir(env);

Or apply override logic to prefer another variable:

var nenv = require('nenv');
function override() {
  return process.env.ENV || process.env.NODE_ENV;
}
var env = nenv(override);
console.dir(env);

Example

See defaults.js.

var env = require('./')()
  , str = JSON.stringify(env.jsonify(), undefined, 2);
process.stdout.write(str);

Executed with NODE_ENV=devel, yields:

{
  "TEST": "test",
  "DEVEL": "devel",
  "STAGE": "stage",
  "PRODUCTION": "production",
  "value": "devel",
  "valid": true,
  "defined": true,
  "map": {
    "test": [
      "test"
    ],
    "devel": [
      "devel"
    ],
    "stage": [
      "stage"
    ],
    "production": [
      "production"
    ]
  },
  "keys": [
    "test",
    "devel",
    "stage",
    "production"
  ],
  "test": false,
  "devel": true,
  "stage": false,
  "production": false
}

Developer

Test

Run the test specifications:

npm test

Readme

Generate the project readme file (requires mdp):

npm run readme

License

Everything is MIT. Read the license if you feel inclined.

Generated by mdp(1).