voldern / get-env-var

Get environment variable

get-env-var

A little function that reads an environment variable from process.env with support for default values and a optional mapping function applied to the data read from the environment.

It will throw an exception if key can't be found and no default value is supplied.

Example

var getEnvVar = require('get-env-var');

getEnvVar('SOME_VAL', 'defaultValue');
getEnvVar('SOME_INT_VAL', Number.parseInt);
getEnvVar('SOME_INT_VAL', 20, Number.parseInt);

Shorthands

The following shorthand methods currently exists. They have the same API as the generic method. The mapping function is applied to the transformed value.

Boolean

getEnvVar.boolean is a shorthand method that returns true if the value equals 'true' and false in all other cases.

Integer

getEnvVar.integer is a shorthand method that calls parseInt(value, 10).

License

MIT

get-env-var's Issues

Ability to apply mapping function over env var

Idea is to be able to apply mapping function on retrieved values. My idea is to have something like this:

const intEnv = getEnvVar("SOME_INT_ENV").map(Number.parseInt).required();

and for optional values with default

const intEnv = getEnvVar("SOME_INT_ENV").map(Number.parseInt).orDefaultValue(42);

but that breaks backwards compability. The other way could be to introduce third argument, but then you can't stack applied functions, and it looks a bit of awkward (esp. when you want to have a mapping function over a value that is required).

getEnvVar.boolean should ignore case

getEnvVar.boolean currently only supports the string true in lowercase as true, it should instead ignore the case of the text string.