Feature: required() if process.env.NODE_ENV != 'test'

[gunar]

Would you be willing to implement it? I can send a PR too if you need me to

[evanshortiss]

@gunar it sounds like you'd like to be able to have the required() function behave differently based on a specific condition - in your case that condition is the value NODE_ENV?

Would you mind providing a code example of how you would like to see this feature work?

[gunar]

@evanshortiss My unit tests require files that require the config.js file, which forces me to have the env vars set in order for tests to pass.

Unit tests don't depend on any environment variable (e.g. AUTH_TOKEN), but I still want to use env-var ❤️

---

Code example

// src/config.js
import * as env from 'env-var'

export const AUTH_TOKEN = env.get('AUTH_TOKEN').required().asString()

// src/businessLogic.js
import * from src/config

// ... business logic code ...

// test/businessLogic.spec.js

import * from src/businessLogic

// ... tests ...

[evanshortiss]

I understand now. I don't think NODE_ENV=test is standard so I would be very cautious adding it to env-var since people will not expect that behaviour, right?

I have some thoughts:

1. Use stubs or mocks in your tests. This is probably the best choice in general.
2. Modify the config.js to change behaviour in test mode.
3. Add a new feature to env-var.
4. Use dependency injection - I list this since it's an option, but might need you to restructure modules

Option 1

Using mocks in your unit tests will allow you to stub/mock out config.js entirely. This is a good approach since you can adjust it for each test case if necessary. I'm not sure what text framework you use, but Jest supports class mocks and has a host of other mocking features. If not using jest, then maybe use proxyquire with mocha or another test runner?

Option 2

You could use fake values if in test mode:

import * as env from 'env-var'

const isTest = env.get('NODE_ENV').asString() === 'test'

const AUTH_TOKEN = isTest ? 'FAKE_VALUE' : env.get('AUTH_TOKEN').required().asString()

Option 3

Add a feature like this in env-var where required accepts an optional parameter function to customise the behaviour.

import * as env from 'env-var'

const isRequired = () => env.get('NODE_ENV').asString() !== 'test'

// required only throw if NODE_ENV is != "test"
export const AUTH_TOKEN = env.get('AUTH_TOKEN').required(isRequired).asString()

[evanshortiss]

option 4

// src/businessLogic

// We do not require config.js here, instead we have it passed by the callee
export default function (config) {
  // use config.AUTH_TOKEN
}

Then in the test:

// test/businessLogic.spec.js

import businessLogic from src/businessLogic

const bl = bl({ AUTH_TOKEN: 'fake token for testing' })

Or in real code:

import businessLogic from src/businessLogic
import * from src/config as config

const bl = bl(config)

[evanshortiss]

@gunar let me know your thoughts

[evanshortiss]

@gunar closing this, but if you have any further input feel free to reopen.

[evanshortiss]

@gunar, check out the new "required()" function behavior. It can support this now.

[gunar]

Thanks @evanshortiss !

[gunar]

const SECRET = env.get('SECRET', 'bad-secret').required(NODE_ENV === 'production').asString()

Very smart.