env

What is this?

Uses Tagged Templates to get environment variables, instead of process.env.

Usage

import { env, envStr } from '@rpappa/env';

console.log({
    envResult: env`TEST`,
    envStrResult: envStr`TEST`,
});

The subtle difference is that envStr returns the empty string when the environment variable isn't set.

> node test.js
{ envResult: undefined, envStrResult: '' }

> TEST=hello node test.js
{ envResult: 'hello', envStrResult: 'hello' }

If a variable is required, you can also use envRequired or envRequiredNonEmpty:

import { envRequired, envRequiredNonEmpty } from '@rpappa/env';

try {
    const TEST_A = envRequired`TEST`;
} catch (e) {
    console.error("envRequired threw an error")
    console.log(e);
}

try {
    const TEST_B = envRequiredNonEmpty`TEST`;
} catch (e) {
    console.error("envRequiredNonEmpty threw an error")
    console.log(e);
}

In this case, envRequired will throw an error if the variable is not set, and envRequiredNonEmpty will throw an error if the variable is not set or is set to the empty string.

Note on escaping

Under the hood both env and envStr call String.raw, so substitutions are processed, but escape sequences are not. This is likely an edge case for environment variables, but nonetheless this gives the following test case:

process.env[String.raw`TEST\ENV`] = 'test';

expect(env`TEST\ENV`).toBe('test');
expect(env`TESTENV`).toBe(undefined);
expect(env`TEST\\ENV`).toBe(undefined);